TM-5-6115-545-34

Micrometers, Inside 5210-00-225-9763 and Outside 5210-00-221-1921

12-3

14-40

14-48

P u l l e r K i t ,

U n i v e r s a l

Gage, Thickness

5180-00-701-8046

( o r e q u i v a l e n t )

5210-00-222-1999

( o r e q u i v a l e n t )

Grinding machine, v a l v e f a c e

T e s t S t a n d , V a l v e

Spring

G r i n d i n g K i t ,

Valve Seat

S e a l I n s t a l l a t i o n t o o l

Allen Wrench

5/32

TESTER CYLINDERI

COMPRESSION

I n j e c t i o n n o z z l e

H o l d i n g f i x t u r e

2-2

Change 6

4910-00-540-4679

( o r e q u i v a l e n t )

5120-00-449-8028

( o r e q u i v a l e n t )

4910-00-473-643 14-39

( o r e q u i v a l e n t )

5120-00-198-5392

( o r e q u i v a l e n t )

4710-00-785-6437

( o r e q u i v a l e n t )

J-6999 (33287)

T e s t r a d i a t o r f o r l e a k s

T e s t n o z z l e h o l d e r a s s e m b l i e s

T e s t f u e l i n j e c t i o n p u m p

M e a s u r e d i m e n s i o n , c l e a r a n c e t h i c k n e s s , a n d u n i f o r m i t y

Remove gears, flywheel and

P u l l e y s

M e a s u r e c l e a r a n c e

R e s u r f a c e v a l v e f a c e

T e s t v a l v e s p r i n g s

Resurface valve seats

F l y w h e e l h o u s i n g s e a l i n s t a l l a t i o n

F u e l i n j e c t i o n p u m p , t r a n s f e r pump delivery valve disassembly

Compression Test

D i s a s s e m b l y o f f u e l i n j e c t o r

Figure 2-0.

Breakout Cable (Sheet 1 of 2)

Change 9

2-2.1

2-2.2

Change 9

Figure

2-O.

Breakout Cable (Sheet

2 of 2)

Table 2-1. TOLLS AND SUPPORT EQUIPMENT, TEST, REPAIR CALIBRATION AND HANDLING

Item

NSN or

Part No

Pin Vise J-4298-1 (33287)

(or equivalent)

Nozzle cleaning J-8537-3 (33287)

Wire (or equivalent)

Injection Nozzle J-21609-7 (33287) bore cleaner (or equivalent)

Snap ring pliers 13337 (84760)

(or equivalent)

Water pump cool5120-00-197-4920 ant seal installer (or equivalent)

Seal Installer

Handle

5120-00-677-2259

(or equivalent)

Soft Faced Ham-

5120-00-900-7882 mer (or equivalent)

Spring Compres5120-00-239-8686 sion Tool (or equivalent)

Valve Seat Instal- 5120-00-473-7393 lation Tool (or equivalent)

Valve spring Test- 5120-00-449-8028 ing Tool

(or equivalent)

Cold box

Fig

Reference

Para

Connecting rod 4910-00-733-2487 checking fixture

(or equivalent)

Piston pin installation and removal tool

Plastic head ham- 5120-00-900-7882 er (or equivalent)

Cylinder honing

001

5130-00-473-6236

(or equivalent)

Depth Micrometer

5120-00-619-4045

(or equivalent)

Use

Disassembly and cleaning fuel injectors

Cleaning injector valve body orifices

Cleaning nozzle bore with cleaning solution

Fuel injection pump governor disassembly

Water pump coolant seal installation

Timing gear cover removal

Crankshaft end play test

Valve spring retainer removal

Exhaust valve seat installation

Intake and exhaust valve spring test

Exhaust valve seat insert installation

Connecting rod length and twist test

Piston pin installation

Connecting rod cap installation

Honing cylinder

Cylinder sleeve sleeves protrusion

(standout) measurement.

Change 3

2-3

TABLE 2-1.

TOOLS AND SUPPORT EQUIPMENT, TEST, REPAIR CALIBRATION AND HANDLING (CONT)

REFERENCE

Item

NSN or

Part No

Fig

Para

Use

14-87

Cylinder sleeve installation Cylinder sleeve installation tool

Brass wire brush 16488 (84760)

(or equivalent)

Holding fixture 5120-00-816-7030

(or equivalent)

14-39

14-45

Cleaning fuel injector nozzle valve body

Facilitates assembly of leaf springs in hydraulic head and rotor assembly.

Kit centrality gage

16182 (84760)

(or equivalent)

Enables adjustment of rollers in hydraulic head and rotor assembly.

Enables installation of delivery valve in fuel injector pump

Delivery valve ex tractor

13383 (84760)

(or equivalent)

Piston ring installation tool

Linkage gage

16199 (84760)

(or equivalent)

13389 (84760)

(or equivalent)

Drive shaft seal assembly tool

13369 (84760)

(or equivalent)

Multimeter

6625-00-553-0142

(or equivalent)

14-45

14-49

Enables adjustment of power piston

Enables adjustment of throttle linkage on fuel injector pump.

Enables installing drive shaft in fuel injector pump

Check resistance

Control box relay testing

Control box relay assembly

Testing

Current transformer testing

Electro-hydraulic governing system malfunction

Electro-hydraulic governing system resistance test

Permissive parallel relay test

Excitation system assembly test

Generator, removal disassembly and test

Battery charging alternator inspection and test.

Speed switch test

14-9

Battery charging alternator Test Set, Gen4910-00-092-9136 erator and voltage (or equivalent) regulator automotive

2-4

Change 3

TABLE 2-1.

TOOLS AND SUPPORT EQUIPMENT, TEST, REPAIR CALIBRATION AND HANDLING (CONT)

Item

NSN or

Part No

REFERENCE___

Fig Para

3-7

8-7

Use

Thermal watt converter testing

Overload relay test

AC Power Supply 17 BU-3 Superior

120/208 Vat, 3

Electric (58474)

Phase, 4 wire (or equivalent)

60 H

C Voltmeter

0-120 VAC

3-4

8-11

Model 904 Weston

(65092) (or equivalent)

8-8

8-19

Model 116B Superior 8-10 8-7

Test stand Actua- 4940-00-152-2107 tor (or equivalent)

AC Ammeter

Model 433

Weston (65092) or equivalent

Short circuit relay test

Excitation system assembly test

Load measuring unit test

Hydraulic actuator test

Overload relay test

Test Set, Gen &

4910-00-092-9136

Voltage Regulator

(or equivalent)

Test Set, armature 6625-00-828-5810

(or equivalent)

Variable voltage Model 1308

Variable frequency General Radio power supply (0-

(24655)

160) VAC, 20-450 (or equivalent)

Battery charging alternator inspection and test

14-28

Electric starter inspection and test

8-7

Short circuit (Bench Test) relay test (400HZ)

Overvoltage relay test

8-7

7-6

Underfrequency relay test (50/60

Hz)

Underfrequency relay test (400HZ

Undervoltage relay test (400 HZ)

Permissive parallel relay test

Electro-hydraulic governor

Magnetic amplifier bias test

50/60 HZ

Electro-hydraulic governor frequency sensing test (50/60 Hz)

Electro-hydraulic governor rectifier bridge and-feedback wind ing test (50/60 Hz)

Electro-hydraulic governor parallel winding test (50/60 Hz)

Electro-hydraulic governor magnetic amplifier bias test (400 H

Electro-hydraulic governor frequency sensing test (400 Hz)

Electro-hydraulic governor rectifier bridge and feedback winding test (400 Hz)

Electro-hydraulic governor parallel winding test (400 Hz)

Change 3

2-5

TABLE 2-1. TOOLS AND SUPPORT EQUIPMENT, TEST, REPAIR CALIBRATION AND HANDLING (CONT)

REFERENCE

Item

NSN or

Part No

Fig

Para

Use

3-10

DC Power Supply

(24 vdc)

DC power supply

27 ± .5 Vdc

DC Power Supply variable voltage(0-5 Vdc)

Model MP40

(98853) (or equivalent)

Model MP4-0

(98853) (or equivalent)

Model MP40 (98853)

(Or equivalent)

13-13

Control box relay assembly test ing

Frequency meter and transducer test

Current transformer testing

Short circuit relay test (bench test)

Overvoltage relay test

Reverse power relay test

Overload relay test

Underfrequency relay test

Undervoltage relay test

Electric governor control unit parallel winding test

Permissive parallel relay

DC relay assembly test

Hydraulic actuator test

Electro-hydraulic governor magnetic amplifier bias test (50/

60 Hz) (Bench Test)

Electro-hydraulic governor frequency sensing test (50/60

Hz)

Electro-hydraulic governor rectifier bridge and feedback winding test (50/60 Hz)

Electro-hydraulic governor parallel winding test (50/60 Hz

Electro-hydraulic governor magnetic amplifier test (400Hz

Electro-hydraulic governor frequency sensing test (400 Hz)

Electric-hydraulic governor receptacle bridge and feedback winding test (400 Hz)

Electro-hydraulic parallel wind ing test (400 Hz)

Reverse power relay test (bench test)

AC Power Supply variable voltage

0-10 VAC)

Electric (variac)

58474) (or equivalent)

Miliammeter dc,

0-1000 ma

6625-00-883-9734

(or equivalent)

7-3 7-6

Reverse power relay test (bench test)

Electro-hydraulic governor magnetic amplifier bias test (50/

2-6

Change 3

TABLE 2-1. TOOLS AND SUPPORT EQUIPMENT, TEST, REPAIR CALIBRATION AND HANDLING (CONT)

REFERENCE

Item

NSN or

Part No.

Fig

Para

Use

7-4

7-6

Electro-hydraulic governor frequency sensing test (50/60Hz)

Voltmeter O-5

Vdc

Model Weston (65092

(or equivalent)

Frequency meter

6625-00-893-0021 set

(or equivalent)

Model 329 (65092)

Electro-hydraulic governor rectifier bridge and feedback winding test (50/60 Hz)

Electro-hydraulic governor parallel winding test (50/60 Hz)

Electro-hydraulic governor magnetic amplifier bias test (400

Hz)

Electro-hydraulic governor frequency sensing test (400 Hz)

Electro-hydraulic governor rectifier bridge and feedback winding test (400 Hz)

Electro-hydraulic governor parallel winding test (400 Hz)

Hydraulic actuator test

Reverse power relay test (bench test)

Underfrequency relay test (400

Hz)

Control box relay assembly test ing(frequency meter and transducer test)

Underfrequency relay test (50/

60 Hz)

3-6 AC Wattmeter testing

AC Wattmeter

Three Phase

Voltmeter 0-10

Vac

Model 904 (65092)

8-18 Load measuring unit test (bench

Test)

Change 3

2-7

TABLE 2-1.

TOOLS AND SUPPORT EQUIPMENT, TEST, REPAIR CALIBATION AND HANDLING (CONT)

REFERENCE

ITEM

NSN or

PART NO Fig Para

USE

Voltmeter 0-50

Vdc

Model 901 (65092)

8-18

Load measuring unit test (Bench test)

Auto transf ormer

5625-00-124-7254

(or equivalent)

Electro-hydraulic governor rectifier bridge and feedback winding test (50/60 Hz)

Electro-hydraulic governor rectifier bridge and feedback winding test (400 Hz)

Miliammeter dc, zero center -10,

0, +10 ma

6625-00-883-9734

7-5

7-9

7-6

Electro-hydraulic governor rectifier bridge and feedback winding test (50/60 Hz)

Electro-hydraulic governor rectifier bridge and feedback winding test (400 Hz)

Solder gun 3439-00-517-0603

(or equivalent)

9-2

Generator removal, disassembly and test

Test Gage and Hose

4910-00-774-9343

(or equivalent)

13-3

13-2

Hydraulic speed control actuator

14-5

14-14

14-16

Hydraulic pump assembly (class

1 precise sets)

Hydraulic pump reassembly, installation and adjustment

Test Stand, Actuator

4940-00-152-2107

(or equivalent)

Test Stand, Magnetic

1910-00-912-3690

(or equivalent)

13-3

13-6

Hydraulic actuator test (bench test)

14-19

Testing speed switch (bench test)

Voltmeter 0-300

Vac

Model 904 (65092)

8-18

Load measuring unit test (bench test)

Power supply 208

Vat, 3 phase 47-

430 Hz

14-12 14-28 Electric starter inspection

8-18

Load measuring unit test (Bench test)

Wheatstone bridge

3625-00-927-4451

(or equivalent)

Megger 500 Vdc

5625-00-581-2466

(or equivalent)

14-12

9-2

and test

14-2

14-29

Electric sater motor repair

14-10

Generator, and test removal, disassemble

Battery charging alternator inspection and test

2-8 Change 3

TABLE 2-10

TOOLS AND SUPPORT EQUIPMENT, TEST, REPAIR CALIBRATION AND HANDLING (CONT)

REFERENCE

Item

NSN or

Part No.

Fig Para Use

Double Kelvin

Bridge

9-2

Generator, removal, disassemble and test

Engine support

Stand

4910-00-808-3372

(or equivalent)

14-3

Support engine after removal from skid base

Engine Stand Adapter plate

J22289-1 (33287)

(or equivalent)

14-3

Support engine after removal from skid base

Engine stand adapter plate spacers

J22289-2 (33287)

(or equivalent)

14-3

Engine jacking stud support angle

70-1419 (93742)

(or equivalent)

Engine jacking stud support angle bol

5/8-11x 1-1/2 ts cap screw (or equivalent)

Engine Jacking stud

70-1420 (93742)

(or equivalent)

Generator lifting 70-1930-(12532) eye bolt

2-1

2-11

Hoist chain, 3 ton 3950-00-292-9879 capacity

(or equivalent)

Dial indicator

0-.1.00

5210-00-277-8840

(or equivalent)

2-1

CR3 (para 14-10). Replace defective

Wrench, socket 5120-00-596-1199

(or equivalent)

Wrench, box 5120-00-930-6346 cylinder short head (or equivalent)

Dial Indicator apdaptor

J-21886 (33287)

Kent-Moore (or equivalent earing retainer installation tool

JD-274 (00713) (or equivalent)

Magnifying glass 6650-00-252-6271

(or equivalent

14-42

Voltage-freqnency

Recorder

6625-00-498-9984

(or equivalent

Support engine on skid base hen removing generator

Provide generator lifting point

Lift generator skid base

Fuel injection or engine from pump reassembly installation of connecting rod cap screws

Torquing cylinder head bolts

Turbocharger end play radial

Turbocharger assembly

Nozzle assembly valve

To evaluate set performance

Change 3

2-9

Table 2-2. Generator Set Troubleshooting

Malfunction

Engine fails to crank when

START-STOP-RUN switch is moved to START position

2. Engine cranks but fails to start

Probable cause

Corrective action

Defective crank relay a.

With START-STOP-RUN switch a.

(K3).

(S2) in START position, check for

24 Vdc across relay K3 (two small terminals) X1 and X2 in set special box If voltage is present, check for voltage across relay contacts, two large terminals.

If voltage is present, relay K3 is defective. Replace relay K3

(para 8-7).

b. Defective CR3 diode.

Gain access to set special relay

assembly (para 8-6).

Test diode

diode.

Defective ring gear.

Inspect ring gear. Replace defective

ring gear (para 14-69 and 14-70).

Starter motor brushes d.

Replace starter motor brushes worn or not contact-

(para 14-26, and fig. 14-10).

ing properly.

Defective starter motor e.

Replace starter motor solenoid solenoid.

(para 14-27 and fig. 14-10) and

adjust (para 14-30 and fig. 14-14).

Defective starter motor.

Replace starter motor (para. 14-25,

and fig. 14-9).

Time as shown in figure 14-34.

a. Incorrect valve and injector timing.

b. Valves burned or sticking.

Valve clearance incorrect.

Check valves (para 14-77). Replace valves (para 14-77 and 14-79),

. Check clearance. Adjust fuel injector (Operator and Organizational Maintenance Manual).

Governor actuator improperly positioned.

Defective solenoid on fuel injection pump.

Dc relay control assembly (A5) defective.

d. Check governor (para 7-2),

Adjust governor actuator

(para 7-8).

Replace defective solenoid

(para 14-46),

NOTE

Gain access to set special relay assembly.

With S2 in START position, measure dc voltage between

A5 terminal 21 and ground stud

It should read 24 Vdc. Measure dc voltage between A5 terminal

23 and ground stud. If no voltage exists, replace dc relay control

circuit assembly (A5) (para 8-6).

2-10

Table 2-2. Generator Set Troubleshooting (Cont)

Malfunction

Engine runs when START -

STOP-RUN switch is held in START position, but stops when switch is put in

RUN b.

Probable cause a _. Defective stoprun relay (Kl).

Defective overvoltage relay (K2).

Corrective action a. Replace defective relay Kl in generator control assembly

(fig

3-3 and 3-5).

defective relay (para 8-6).

Engine runs rough

Engine runs erratically or misfires

Engine runs but fails to reach rated speed c.

Defective fuel level relay the special relay assembly

(para 8-6).

— a.

Incorrect timing.

Defective fuel injection pump.

Nozzle injector d.

assembly mal function.

Sticking valves.

figure 14-25.

b. Check fuel injection pump

(para. 14-44). Repair or re-

place fuel injection pump

(para 14-44 and 14-45).

— c. Repair or replace nozzle

injector assemblies (para

14-38 thru 14-41).

d. Check valves and springs

(para. 14-77). Repair or replace valves (para 14-77 thru 14-78).

e. Replace cylinder head gasket

(para 14-79. )

— f. Replace cylinder sleeve (para

14-85 thru 14-87).

Blown cylinder head gasket.

Defective cylinder sleeve.

Defective piston.

Broken or bent push rod.

14-81 thru 14-83).

Improper fuel timing.

Improper governor adjustment.

Defective fuel injection pump.

anism. Replace defective push

rod (para 14-77).

a. Time fuel injection pump

(para 14-4 9).

b. Adjust governor (para 7-8).

c. Inspect fuel injection pump,

Replace or repair (para

14-49, 14-44 and 14-45).

Deleted e. Worn camshaft bear e. Replace camshaft bearing ings.

(para 14-85 and 14-87).

Improper governor adjustment.

a. Adjust governor (para 7-8).

Change 5 2-11

2-12

Malfunction

Engine runs but fails to reach rated speed.

(Continued)

10.

Low oil pressure

High oil pressure

Engine lubricating oil consumption high

Engine noisy

Table 2-2. Generator Set Troubleshooting (Cont) b.

Probable cause

Lack of fuel.

Defective fuel injection pump.

Defective oil pump.

Worn main bearing.

Main bearings worn.

Oil leaks at crankshaft seals

Main bearings worn.

Connecting rod bearings worn.

Piston pins loose.

Piston or rings broken.

Timing gears worn.

Corrective action b. Check fuel level. Replenish if necessary. (Operator and organizational maintenance manual).

Inspect fuel injection pump. Repair or replace as required

(para 14-44 and 14-45).

Replace oil pump (para 14-65

thru 14-67).

Replace main bearings (para

14-85 thru 14-87).

— c.

Replace defective valve in

cylinder block (para 14-78

and 14-87).

Defective oil regulating valve (oil pressure below 45 psi).

Defective oil regulating valve. (oil pressure above 45 psi)

Pistons, sleeves or rings worn or defective.

Crankshaft journals eccentric or out of round.

Connecting rods miss.lined.

Incorrect valve adjustment,

Replace defective valve in cylinder

block (para 14-78 and 14-87).

Replace pistons and rings (para.

14-81 thru 14-83). Replace

cylinder sleeve (para 14-85

thru 14-87).

Replace main bearings (para

14-85 thru 14-87).

Replace seal (para 14-85 thru

14-87).

Replace if required (para 14-85

thru 14-87).

Replace if required (para 14-81

thru 14-83).

— c.

Replace the piston or rings

(para 14-81 thru 14-83),

— d.

Replace pistons or rings

(para 14-81 thru 14-83).

Inspect gear fit and replace

gears if required (para 14-72

thru 14-74).

f. Inspect crankshaft and repair

or replace (para 14-85 thru 14-

87).

g. Realine connecting rods (para

14-82).

h. Check valve adjustment.

Adjust valves (Operator and

Organizationl Maintenance

Manual).

10.

11.

12.

13.

Excessive generator set vibration

14.

Malfunction

Engine noisy

(Continued)

Engine overheats

Engine lacks power

Noisy turbocharger

Table 2-2. Generator Set Troubleshooting (Cont) i.

Probable cause

Flywheel loose.

Corrective action i.

Inspect flywheel attaching bolts

and tighten if required (para

14-69 and 14-70).

Deleted b.

Water pump defective.

Radiator leaks or is clogged.

Defective shutter or shutter linkage.

Defective actuator.

Valves burned or sticking.

Piston rings worn or defective.

Defective nozzle injector assembly.

Defective fuel injection pump.

Repair or replace water pump

(para 14-57 thru 14-50).

Repair or replace radiator

(para 12-2 thru 12-4).

Repair or replace shutter and

shutter linkage (para 12-2

thru 12-4).

Isolate trouble (para 13-2).

Repair or replace actuator

(para 13-3).

Isolate trouble (para 14-77).

Replace valves (para 14-77

thru 14-79).

Replace piston rings (para

14-81 thru 14-83).

Repair or replace nozzle

inject or assembly (para

14-38 thru 14-41).

Isolate trouble (para 14-43).

Repair or replace and test fuel injection pump. (para 14-

43 thru 14-45 and 14-48).

Improper engine timing.

Defective valves.

Time engine as shown in figure

14.25.

Isolate trouble (para 14-77),

Replace valves (para 14-77

thru 14-79).

Fuel injector pump assembly malfunction.

Isolate trouble (para 14-43).

Clean, repair or replace

injectors (fig. 14-21).

Loose flywheel or flywheel housing mounting.

Loose vibration dampener.

Worn turbocharger bearings c.

Tighten flywheel bolts or

housing bolts (para 14-69).

Inspect vibration dampener.

Tighten vibration dampener

(para 14-60, 14-61 and 14-63).

Inspect turbocharger. Repair or rebuild turbocharger (para

14-52 thru 14-55).

Change 3 2-13

Malfunction

14.

Noisy turbocharger (Continued)

15.

16.

17.

18.

Turbocharger leaks oil

Excessive gear noise around front of engine

Low engine compression

Main generator output voltage too low

Table 2-2. Generator Set Troubleshooting (Cont) d.

Probable cause b. Excessive turbocharger impeller end play.

Worn or broken turbocharger shaft seal ring.

Worn or broken turbocharger oil pressure and drain seal rings.

Defective vibration dampener.

Excessive timing gear backlash.

Defective piston rings.

Defective pistons and cylinder sleeves.

Leaking or defective valves.

Exciterregulator defective.

Rotor assembly defective.

c. Stator defective.

Exciter rotor defective.

Exciter stator defective.

Corrective action

Measure end play (para 14-52).

Disassemble and add correct

number of shims (para 14-52

and 14-55).

Inspect turbocharger. Replace

shaft seal ring (para. 14-53,

thru 14-55).

Inspect turbocharger. Replace turbocharger oil pressure and

drain seal rings (para 14-53

thru 14-55).

Inspect vibration dampener.

Replace vibration dampener

(para 14-60,14-61 and 14-63).

Inspect timing gears (para

14-73). Replace timing

gears (para 14-72 and 14-75).

Replace piston rings (para

14-81 thru 14-83).

Replace pistons (para 14-81 and

14-83) and cylinder sleeves

(para 14-85 thru 14-87).

Isolate trouble (para 14-77).

Replace valves (para 14-77

thru 14-79).

Check exciter regulator (para 8-3).

Replace exciter voltage regulator

(para 8-10 thru 8-14).

Check rotor resistance.

Check for shorts or grounds. Replace, repair

or rebuild if required (para 9-2,

9-3,9 -4,9-6 and 9-7).

Check stator resistance.

Check for grounds or shorts.

Replace, repair or rebuild

if required (para 9-2, 9-3, 9-4,

9-6 and 9-7).

Check exciter resistance.

Check for shorts or grounds

(para 9-2). Replace exciter

if defective. (para 9-5, 9-6

and 9-7).

Check exciter stator resistance.

Check for shorts or grounds

(para 9-2). Replace exciter

stator (para 9-5,9-6 and 9-7).

2-14

19.

20.

21.

22.

too high.

fluctuates or drifts.

Main generator fails to flash.

Table 2-2. Generator Set Troubleshooting (Cont)

Malfunction

18.

Main generator output voltage too low.

Main generator output

Main generator noisy.

Main generator frequency

Probable cause f.

Rotating diodes defective.

Exciter-regulator a.

defective.

Defective bearing.

Generator fan loose or defective.

Governor system defective.

Engine malfunctioning.

Field flash circuit defective.

Corrective action

Check diodes (para 9-3). Re-

place diodes as required.

(Operator and Organizational

Maintenance Manual).

Check exciter regulator

(para 8-3). Replace

exciter voltage regulator

(para 8-10 thru 8-14).

Replace bearing (para 9-2

and 9-6).

Inspect generator fan.

Tighten, repair or replace

fan (para 9-2, 9-3 and 9-6).

Adjust governor system (para

7-2). Repair or replace as

required (para 7-3 thru 7-6).

See items 4, 5, and 6.

Defective exciter rotor.

Defective exciter stator.

Defective rotating diodes.

Defective generator stator.

Defective speed switch.

Defective excitation assembly.

Check field flash relay (K5)

(fig.1-11).

Disconnect battery negative . Disconnect

J9 on regulator. Apply 24 Vdc to terminals 13(+)and 15(-) on

A5 assembly.

Check continuity between terminals 1-14 and 2-15.

If circuit is open, replace K5 relay on A5.

Check R219 and

CR207 in exciter regulator

(para 8-3). Replace defective

components as required (para

8-10 thru 8-14).

Check resistance of exciter rotor.

Check for short or ground. Re-

place as required. (para 9-2,

9-3,9 -5,9-6 and 9-7).

Check resistance of exciter stator. Check for short

or ground (para 9-2).

Replace as required. (para 9-2,

9-3, 9-5, 9-6 and 9-7).

Check rotating diodes (para

9-3). Replace any defective

diode (para 9-2 and 9-6).

— e.

Check generator - stator resis-

Check for short or ground

para 9-2).

Repair or rebuild as required.

(para 9-3,9 -4,9-6 and 9-7).

Check S9-1, normally open, for

proper operation (para 14-19).

Check R225 and R226

(para 8-12).

Change 5

2-15

23.

240

25.

26.

Malfunction

Table 2-2. Generator Set Troubleshooting (Cont)

Probable cause

Corrective action

Frequency meter fails to register.

Frequency meter defective.

Replace meter and transducer

(Refer to Operator and Organizational Maintenance Manual).

b. Frequency transducer defective.

Replace frequency meter and transducer (Refer to Operator and Organizational Maintenance

Manual).

Engine speed too low.

— c.

Raise engine speed to rated value.

(Refer to Operator and Organizational Maintenance Manual).

Percent power meter fails to register.

Percent power meter defective.

Thermal watt converter defective.

Set operating at no-load.

Replace meter (Refer to Operator and Organizational Maintenance

Manual).

Replace thermal watt converter

A1 (para 3-7).

Adjust load bank or apply load.

(Refer to Operator and Organizational Maintenance Manual).

Units paralleling out of phase (B2) (contactor closing when paralleling lights are bright).

Permissive paralleling relay (K16) defective.

Remote sensing inoperative.

Measure ac voltage between 1 and 2 on K16. When lights are the brightest, 120 volts should exist; voltage should decrease toward zero, as lights dim. If voltage is

OK, remove leads from relay pins 7 and 8. Measure continuity across pins 7 and 8 while observing volt meter connected at pins 1 and 2. Continuity should exist at 9 volts and below.

There should be no continuity at 9 volts and above. Replace

defective relay K16 (para

8-6 and 8-7).

Place switch in correct position.

Check switch for continuity in all positions.

(Refer to Operator and Organizational Maintenance

Manual).

Local - Remote voltage switch

(S5) on control panel in local position or defective.

Remote sensing leads not connected to sensing point.

K6 relay defective.

Control panel relay (A4) components

(R10 and CR1) defective.

Check connections. Make correct connections,

Check relay K6. Replace if

defective (para 3-5 and 3-10).

Replace R10 or CR1 if defective

(para 3-3 thru 3-5).

2-16

Change 5

Malfunction

27.

Generator runs at 130 percent or more rated current for longer than 10 minutes,

CB2 does not open and overload indicator does not light.

Table 2-2. Generator Set Troubleshooting (Cont)

Probable cause a.

Defective overload relay (K14).

Defective resisters R23, R24 or R25.

Defective current transformer CT1,

CT2 or CT3.

Defective overvoltage relay K2.

Corrective action a.

Replace K14 (para 8-6

and 8-7).

Replace resistor R23, R24 or

R25, if ohmmeter test indi-

cates defect (fig. 8-2 and 8-3).

Replace defective current’ transformer CT1, CT2 or

CT3 (para 6-7 thru 6-8).

Replace overvoltage relay (para 8-6

and 8-7).

28.

Generator runs at overvoltage (130 percent.

Set does not shut down and overvoltage indicator does not light.

29.

Generator runs under voltage (85 percent of rated voltage or less).

CB2 does not open and undervoltage indicator does not light

(Class I only)

30.

Percent power meter reads down scale with

2 or more sets paralleled.

Defective undervoltage relay Kil o

Reverse power relay

(K15) defective.

Replace undervoltage relay K11

(para 8-6 and 8-7).

Measure dc voltage at K15 terminals

3 and 4. It should be 24 volts

(positive on terminal 3). Check for Vdc at pins 1 and 2. If 2 or more Vdc are present with 1 positive

replace reverse power relay (para

8-6 and 8-7).

31.

Set starts but will not run unless protection bypass switch (S7) is closed.

System fault as indicated by fault indicator panel.

Correct indicated fault.

If no lamp is illuminated, press fault indicator test switch to ensure that all lamps are working.

Overvoltage relay K2.

NOTE

If the corrective action in a and b above does not correct the malfunction, proceed to determine if one of the following components are defective by placing jumpers across their contacts as follows: c.

Replace any defective lamps.

Terminals 3 and 4 of K2.

Low oil pressure switch OP and high coolant temperature switch WT.

Terminal 3 of K2 and 4 of AS.

Change 5

2-17

2-18

Malfunction

32.

Paralleling lights, DS4 and/or DS5, will not light with S6 in parallel position

33.

Improper governor operation (i. e., load sensing)

Table 2-2. Generator Set Troubleshooting (Cont)

Probable cause

Corrective action e.

Fuel level relay K8.

Terminals 4 and 16 of A5.

NOTE

Start the generator set and open the protection bypass switch S7.

Remove the jumpers installed in c, d, and e above. If the set stops when one of the jumpers is removed, that component is defective and must be replaced.

If the set shuts down when the jumper in step d is removed test OP and WT and replace the defective component.

DC relay control circuit assembly

(A5) defective.

Current transformer resistor board (A7) defective.

With set stopped, check resistance between A5 terminals 7 and 8 for

DS5, and terminals 19 and 20 for

DS4. Resistance should be 7500

Ohms ±5.0 percent. If no continuity,

replace dc relay board (A5) (para 8-6

and 8-7).

Measure resistance of R23, R24, and R25 on A7 (located in precise relay box on Class 1, Mode

1 sets - in set special box on other sets). Replace any resistor that does not read 7.5 ohms ±0.5

percent (fig. 8-2 and 8-3).

34.

Generator set hunts

35.

Main AC contactor (CB2) will not close

Governor resistor board capacitor (Cl ) defective

(Class I only) a.

Defective short circuit relay

K13.

Defective overload reload relay K14.

Defective reverse power relay K15.

Defective undervoltage relay K11.

(Class I only) e.

Defective underfrequency relay K12.

Defective permissive paralleling relay K16.

Defective contactor switch S3.

Check capacitor (C1) on A6, between pins 5 and 6. Replace a defective capacitor. (60 mfd non-polarized)

(fig. 8-4 and 8-5).

Check relay K13. Replace if

defective (para 8-6 and 8-7).

“ d.

Check relay K11. Replace if

defective. (para 8-6 and

8-7).

Check relay K12. Replace if

defective. (para 8-6 and

8-7).

Check relay K16. Replace if

defective (para 8-6 and 8-7).

Check relay K14. Replace if defective.

Check relay K15. Replace if

defective (para 8-6 and 8-7).

Check switch S3. Replace if

defective. (para 6-2).

Malfunction

36.

Electric governor not controlling set.

(Class I only)

37.

Generator sets will not parallel and share real (kw) load.

38.

Generator sets wilI not parallel and share reactive load.

Table 2-2. Generator Set Troubleshooting (Cont)

Probable cause a.

Defective electric governor control unit .

Corrective action

– a.

Isolate (para 7-2).

Adjust, repair or replace as

required (para 7-2 and 7-4).

Low hydraulic pressure.

Defective hydraulic actuator.

Isolate (para 14-14 and correct

trouble. (para 14-15 and 14-16).

Isolate (para 13-2).

Repair or replace actuator

as required (para 13-3 thru 13-5).

For a Class 1 set, Precise,

refer to paragraph 7-2.

Governor is not adjusted correctly.

Fuel injection pump is not adjusted properly.

For a Class 11 set, Utility,

refer to paragraph 14-45.

Exciter regulator system

Refer to paragraph 8-14 for correct

including the reactive adjustment procedures.

load sharing potentiometer (R29) is not correctly adjusted.

NOTE

Additional troubleshooting procedures

are contained in Tables 8-1 and 14-1.

Change 5

2-19

2-10. General.

This section contains instructions for removal and installation of major components of the generator set to facilitate repair and overhaul procedures.

Removal of assemblies and repair and overhaul instructions are covered in subsequent sections of this manual.

2-11. Generator Removal.

See figure 2-1 for location of major components.

— a. Disconnect the ground cable from the battery.

b. To remove the following refer to the Operator and Organizational Maintenance Manual.

(1) Receptacle panels (as required).

(2) Manual speed control.

(3) Fault indicator.

(4) Control cubicle.

(5) Rear grille.

(6) Rear panels and doors.

(7) Rear roof and corner posts.

(8) Main load contactor.

(9) Load terminal board.

(10) Reconnection board.

(11) Air cleaner.

c. See figure 6-2 for removal of main generator

leads from current transformer assembly. Before removing current transformer assembly, tag 18 harness wires from terminal strip and identify the leads which are passed through the current transformers more than once.

d. See para 6-8 for removal of current trans-

former assembly.

e. On Class I sets only, remove the governor

control unit and mounting bracket. (See para 7-3. )

f. Remove the relay table group. (See para 8-5.)

g. Remove generator.

See figure 2-2 and proceed

as f

O ll

OWS

(1) Position engine jacking supports on the engine flywheel housing. Adjust engine jacking studs by hand until firm contact is established with skid base.

Section IV. REMOVAL AND INSTALLATION OF MAJOR COMPONENTS

(2) Insert generator lifting eye bolt in top of generator housing and attach suitable lifting device.

(3) Remove two screws and two flat washers and two lockwashers on each side of generator housing near forward end and remove access cover and screen.

(4) Remove 4 generator mounting screws, 8 washers and 4 nuts.

(5) Adjust jacking studs to support the weight of the engine, approximately 1/2 turn beyond hand tight.

(6) Reaching through inspection holes in generator housing, bend lockstrips away from heads of eight fan-coupling screws securing generator coupling. Remove the screws to separate the engine and generator at the coupling. Removal of these screws also frees the fan. To facilitate access to the screws, rotate the engine.

(7) Reaching through inspection holes in forward end of generator, remove 12 rim coupling screws and washers around perimeter of flange mating engine to flywheel housing.

2-12. Generator Installation.

Using a suitable lifting device, position main generator mounting pads in skid base and line up generator mounting flange with flywheel housing.

b. Install 12 screws and washers through generator front flange into flywheel housing. Torque screws to 35 foot-pounds.

c. Reach through generator inspection holes, support fan to line up holes and install eight fan coupling screws each with a lockstrip. Before tightening make sure lockstrip extension is in small hole adjacent to threaded screw hole. Torque bolts to 110 foot-pounds.

Bend lockstrip corners against screw head flats.

d. Install four main generator mounting screws and washers and secure with four nuts and 8 washers.

Do not torque screws at this time.

e. Loosen and remove engine support brackets.

f. Torque generator mounting screws to 440 foot-pounds.

g. Install screen and access cover on generator and secure with two screws, two flat washers, and two lockwashers on each side.

h. See figure 8-1 and install relay table group in

reverse order of removal.

2-20

Change 3

Figure 2-1.

Component Locations (Right and Left Side)

2-21

Figure 2-2. Generator Removal i. On precise sets, install the governor control unit and mounting bracket in reverse order of re-

moval (fig. 7-1).

j. See figure 6-3 and install current trans-

former assembly in reverse order of removal.

k. See figure 6-2 and thread generator output

cables through current transformers in reverse order of removal. Connect 18 tagged harness wires to terminal strip on transformer assembly.

l. Refer to the Operator and Organizational

Maintenance Manual and install the following:

(1) Air cleaner.

(2) Reconnection board.

(3) Load terminal board.

(4)

Main load contactor.

(5)

Rear roof and corner posts.

(6) Rear panels and doors.

(7) Rear grill.

(8) Control cubicle.

(9)

Fault indicator.

(10)

Manual speed control.

(11)

Receptacle panels (as required).

2-22 Change 1

m. Connect tagged cables and harness wires to lugs on rear of voltage reconnection panel. Mount reconnection board with attaching hardware on left side. Right side of panel will attach to load contactor. Reconnect the ground cable to the battery.

n. If the generator has been renewed or repaired

refer to Chapter 16, Section II and conduct the follow-

ing tests.

(1) Phase balance test.

(2) Regulator and governor stability and transit response.

2-13. Engine Removal.

a. Drain the engine cooling and lube systems and-the hydraulic sump, as instructed in the

Operators and Organizational Maintenance

Manual.

b. Disconnect the ground from the batteries.

c. Drain fuel from the day tank and secondary fuel filters.

d. Refer to the Operator and Organizational

Maintenance Manual for sequential removal of the following items:

(1) Crankcase breather cover and tubing.

(2) Rain cap and exhaust system.

(3) Receptacle panels.

(4) Housing and cooling groups.

(5) Manual speed control.

(6) Interconnecting wiring harnesses.

(7) Fuel filters, day tank, mounting bracket, and related fuel lines.

(8) Engine drain lines.

filter.

(9) On precise sets only, hydraulic sump and

(10) Winterization kits (if installed).

e. Remove all components of the relay table group and load connection group as instructed in

paragraph 2-11.

f. Remove the top bracket from the lifting frame

assembly. (fig. 11-1)

Position jacking studs under rear of engine

an adjust to support engine weight (fig. 2-2).

Remove four fan coupling screws (para 2-11)which

are to be used as attaching hardware for the jacking support bracket. Remove alternate fan coupling screws only at this time.

h. Attach suitable lifting device to engine hoist brackets,

i. Uncouple generator from engine (para 2-11).

Remove the remaining four coupling screws.

j. Remove two screws securing engine front

mounting bracket to skid base (fig. 2-3).

k. Hoist engine up and forward to clear generator, and lift out of skid base. Place engine on flat surface with a supporting block under front support or place in engine support stand.

2-14. Engine Installation.

a. Place jacking studs on engine flywheel housing with mounting hardware.

b. Hoist engine with suitable lifting device and lower engine into mounting position.

c. As engine front mounting bracket nears engagement with skid base, adjust jacking studs, lower engine until it rests on the skid base and its flywheel housing mates with generator front mating flange.

d. Secure front mounting bracket with attaching hardware. Torque engine mount bolts to 90-100 foot-pounds.

f. Install relay table with attaching hardware.

g. Install control relay boxes and excitation system assembly with attaching hardware.

h. Install top bracket with attaching hardware.

(fig.11-1.)

i. Install housing.

Refer to the Operator and

Organizational Maintenance Manual and install the following: filter.

(1) Winterization kits (if installed).

(2) On precise sets only, hydraulic sump and

(3) Engine drain lines.

(4) Fuel filters, day tank, mounting bracket and related fuel lines.

(5)

(6)

(7)

Interconnecting wiring harnesses.

Manual speed control.

Housing and cooling groups.

(8) Receptacle panels (as applicable).

Change 1 2-23

2-24 Change l

Figure 2-3. Engine Removal

(9) Rain cap exhaust system.

(10) Crankcase breather cover and tubing.

2-15. Engine Generator Assembly Removal.

a. Follow all instructions for disassembly given

in paragraphs 2-11 a thru 2-11 f and 2-13 a thru 2-13 f.

b. Insert the lifting eye in the socket on top of the generator.

c. Attach a suitable lifting device to the front engine hoist bracket and the generator lifting eye.

(fig. 2-4.)

d. Remove the four screws securing the generator to the skid base.

e. Remove two screws securing the engine front support to the skid base.

f. Hoist assembly up and out of skid base. Place on a flat surface with supporting block under engine front support.

2-16. Engine Generator Assembly Installation.

Install and reassemble in reverse order of removal.

Torque engine mount bolts to 90-100 foot-pounds and generator mounting bolts to 440 foot-pounds.

2-25

2-26

Figure 2-4. Engine Generator Removal

CHAPTER 3

GENERATOR SET CONTROLS REPAIR INSTRUCTIONS

3-1. General.

This chapter includes repair instructions for the fault indicator panel and the control cubicle. Test procedures for the control cubicle include individual tests for the converter, control box, relay assembly, frequency meter and transducer, ac wattmeter and ac ammeter.

Section I. INTRODUCTION

3-2. Generator Set Controls Description.

The generator set controls are mounted at the rear of the set, and provide all monitoring and control devices required to operate the set. Controls consist of the fault indicator panel, the control cubicle, and the manual throttle control.

Refer to the Operator and Organizational Maintenance Manual for manual throttle control repair instructions.

3-3. Removal, Disassembly and Repair, a. Removal. Refer to Operator and Organizational Maintenance Manual and remove the fault indicator panel.

b. Disassembly. See figures 3-1 and 3-2 and

disassemble t he fault indicator panel.

cloth.

Section II.

FAULT INDICATOR PANEL

(1) Clean all components with low pressure compressed air, or wipe clean with dry, lint free

(2) Inspect for broken fuseholders, cracked or broken lamp holders, damaged wire insulation, broden wires and bent or broken connector pins.

(3) Remove any components that show visual damage, such as broken fuseholder, or broken lamp

holder (fig. 3-1).

(4) Replace circuit board if broken, cracked or distorted.

(5) Resistors may be checked by breaking connection at one end to prevent feedback resistance and touching both ends with ohmmeter probes. Re-

sistors R1 through R10 (fig. 1-2) should read 2. 2K

ohms ±10 percent.

Resistors R11 through R20 should read 1K ohms ±10 percent. Any variation in excess of 10 percent indicates that the resistor should be replaced.

If any connections are opened or bared for test purposes or if any defective components are replaced, the affected area must be coated with polyurethane resin to prevent oxidation or other corrosion. The coating must be of a minimum thickness of O. 007 inches and air bubble entry into the applied polyurethane must be controlled so that the legibility of component coding and identification is not impaired.

The polyurethane resin to be utilized will correspond to MIL-I-46058 grade S,

Type PUR.

(6) Unplug relay 17, (fig. 3-1) in fault indica-

tor panel and check resistance of relay coils with ohmmeter probes across pins 3 and 7. Reading should be 300 ohms ±10 percent. Replace relay if variation exceeds 10 percent. Plug relay into circuit board.

(7) Rebuild wiring harness if inspection reveals 30 percent or more defective wires. Wiring harness rebuilding instructions are described in

Chapter 5. Otherwise replace damaged wires.

3-4. Reassembly, Testing and Installation.

a. Reassembly. See figures 3-1 and 3-2 and re-

assemble the fault indicator panel.

b. Testing. See figure 1-2. To test the fault in-

dicator panel, proceed as follows:

(1) Connect 24Vdc, positive to pin A of terminal board.

(2) Connect 24Vdc negative to pin B and case.

light.

(3) Operate reset switch. All lights should

(4) Connect pin C to pin D. Low oil pressure light should light.

(5) Open C to D connection. Low oil pressure lights should remain on.

(6) Connect pin C to pin E. Low oil pressure light should remain on.

(7) Operate reset switch. Low oil pressure light should go out and overspeed switch should light.

3-1

1. Screw

2. Fuseholder

3. Switch

4. Tiedown strap

5. Tiedown strap

6. Capacitor

7. Lampholder

8. Cover

9. Screw

10. Cover

11. Screw

12. Plate assembly

13. Screw

14. Component board assembly

15. Screw

16. Washer

17. Relay

18. Screw

19. Wiring harness

20. Chassis

ME 6115-545-34/3-1 C7

3-2 Change 7

Figure 3-1.

Fault Locating Indicator

1. Socket

2. Nut

3. Washer

4. Washer

5. Spacer

6. Resistor

7. Resistor

8. Rectifier

9 .

Rectifier

10. Capacitor

11. Terminal

12. Board

13. Insulation

14. Wire

15. Wire

Figure 3-2. Assembly, Fault Indicator

ME 6115-545-34/3-2 C7

Change 7 3-3

TM 5-6115-545-34

(8) Repeat paragraphs (5), (6), and (7) above for other lights, connecting pin C to pins F, G, H, I, K, L, M, and N.

c. Installation. Refer to Operator and Organizational

Maintenance Manual and install the fault indicator.

Section III. CONTROL CUBICLE

3-5. Removal, Disassembly and Repair.

WARNING

To avoid serious injury to personnel before doing any work in the control cubicle, be sure all power circuits are disconnected. Never work in the control cubicle while the engine is running.

Killing voltages are present.

a. Removal. Refer to Operator and Organizational Maintenance Manual and remove the control cubicle.

b. Disassembly. Refer to Operator and Organizational

Maintenance Manual and disassemble the control cubicle,

See figure 3-3 and disassemble the relay assembly.

c. Vary load and compare the readings of the ac wattmeter on the set with readings of the master wattmeter.

d. The operating set wattmeter error must not exceed 10 percent of full scale value. If it does, replace the ac watt-

meter. If it does not, proceed to para 3-7.

3-7. Transducer Testing.

To test the control cubicle watt transducer, proceed as follows; a. Connect the watt transducer to the test equipment

as illustrated in figure 3-4. Use a calibrated % of rating

meter.

b. Adjust all autotransformers T1, T2 and T3 to their

MIN positions.

c. Close switch S1 and open switches S2 and S3.

(1) Clean all components with low pressure compressed air, or wipe clean with dry, lint free cloth.

(2) Inspect for broken fuseholders, cracked or broken lamp holders, damaged meters, broken terminals on components, damaged wire insulation, broken wires and bent or broken connector pins.

(3) Replace any components which show visual damage, such as cracked or broken meters, broken lamp holders, or cracked or broken switches and rheostats.

(4) Inspect control panel relay assembly for damage.

Replace component (fig. 3-3) if damage is evident. If any

connections are opened or bared for test purposes, or if any defective components are replaced, the effected areas and components must be coated with polyurethane resin to prevent oxidation or other corrosion. The coating must be a minimum of 0.007 inches and air bubble entry into the applied polyurethane must be controlled so that the legibility of component coding and identification is not impaired. The polyurethane resin to be utilized will correspond to MIL-

I-46058 grade S, Type PUR.

3-6. AC Wattmeter Convertor Testing.

To test the ac wattmeter of the control cubicle proceed as follows: a. Connect a master 3-phase wattmeter of known accuracy (1/2 of 1 percent) and a suitable variable load to the output of terminal lugs of the generator set.

3-4

Change 8 e. Adjust T1 until 600 milliamperes is indicated on ammeter A1. The % of rating meter of known accuracy should indicate approximately 33%.

f. Close switch S2 and adjust T2 until 600 milliamperes is indicated on ammeter A2. The % of rating meter should indicate approximately 66%.

g. Close switch S3 and adjust T3 until 600 milliamperes is indicated on ammeter A3. The

% of rating meter of known accuracy should indicate 100%.

satisfy the above requirements.

i. If the transducer meets the above requirements, replace the wattmeter.

3-8. AC Ammeter Testing.

To test the ac ammeter of the control cubicle, proceed as follows: with the set ac current meter.

terminals and compare the readings of the two meters.

c. The generator set ac ammeter error must not be greater than 2 percent of full scale value. If it is, replace the ac ammeter.

1. Screw

2. Relay

3. Socket

4. Nut

5. Washer

6. Washer

7. Spacer

8. Screw

9. Nut

10. Washer

11. Terminal board

12. Rectifier

13. Resistor

13A. Capacitor

14. Board

ME 6115-545-34/3-3 Cl

Figure 3-3. Relay Assembly

Change 1 3-5

TM 5-6115-545-34

Figure 3-4. Control Cubicle Transducer, Test Setup

3-9. Frequency Meter and Transducer Test.

3-10. Control Box Relay Testing.

To test the frequency meter and transducer of the control cubicle, proceed as follows:

To test the control box relay assembly of the control cubicle

(see figure l-l) and proceed as follows:

CAUTION

—

NOTE

The frequency meter and transducer are a matched set and must be tested as a set.

to the ac side of the frequency transducer,

When applying the 120 Vac to control box relay assembly terminals, insure correct placement of power supply leads. Damage to other components could result if leads are inadvertently misplaced.

b. Connect a master frequency meter across the input.

The master frequency meter shall have inaccuracy of a minimum of 3/4% or greater of the set frequency meter and transducer (l/20 of l percent).

a. With no power applied, check continuity across following terminals of the control box relay assembly: terminals

10 and 11; 5 and 6; and 1 and 3 (fig. l-l).

c. Vary the frequency from lowest scale reading to full scale reading.

b. Apply a dc voltage of 24 volts to terminals 2 and 8.

The normally open contacts between terminals 7 and 9, and the normally closed contact between terminals 1 and 3

should transfer (fig. l-l).

d. The error at any point infrequency meter shall not be greater than l percent.

e. If the above requirements are not satisfied, replace both the frequency meter and transducer.

c. Apply an ac voltage from 50 to 80 volts, 50/60 Hz or

400 Hz to terminals 4 and 12. The normally open contacts between terminals 4 and 6, and terminals 10 and 12 and the normally closed contacts between terminals 5 and 6, and

terminals 10 and 11 should transfer (fig. l-l).

3-6 Change 8

d. Connect 120 Vac 60 Hz power supply to terminals 4 and 12 of the control box relay assembly.

Measure voltage at terminals 6 and 10. Voltage

should be 120 Vac (fig. 1-1).

e. Measure dc voltage across relay K6. Voltage

should be above 18 Vdc (fig. 1-1).

3-11. Control Cubicle Wiring Harness.

Rebuild wiring harness if inspection reveals 30 percent or more defective wires. Wiring harness re-

building instructions are described in Chapter 5.

Otherwise replace damaged wires.

3-12. Control Cubicle Reassembly, Testing and

Installation.

a. Reassembly. Refer to Operator and Organizational Maintenance Manual and reassemble the control cubicle.

b. Testing. Refer to the Operator and Organizational Maintenance Manual (Control cubicle, s thematic diagram) to test the assembled control cubicle.

(1) The following control cubicle component

tests are described in paragraphs 3-6 through 3-10

respectively

Ac Wattmeter

Converter

Ac Ammeter

Frequency meter and transducer

Control box relays

(2) Wiring test.

( a ) Using an ohmmeter, check the wiring from each-pin of receptacle J1 to the last point of its connection.

( b ) Where the wiring of two or more pins of the receptacle can be tested by a switch closure, close the switch and complete the teat. After completing the test, return the a switch to its normal position.

(3) Oil pressure gag e test.

( a ) Connect the positive lead of a variable dc power supply, adjusted for 28.5 Vdc, to pin small w of receptacle J1.

( b ) Connect the negative lead of the power supply via a 0-50 ohm 100 watt potentiometer adjusted for 15 ohms to pin V or receptacle J1.

minutes.

( c ) Turn on the power supply and wait 3

( d ) After 3 minutes have elapsed, the oil pressure gage should indicate 60 psi.

( e ) Turn off the power supply and disconnect the test circuit.

(4) Water Temperature gage test.

( a ) Connect the positive lead of a variable voltage dc power supply, adjusted for 28.5 Vdc, to pin small w of receptacle J1.

( b ) Connect the negative lead of the power supply via a 0-2K ohm S watt potentiometer adjusted for 917 ohms, to pin W of receptacle J1.

minutes.

( c ) Turn on the power supply and wait 3

( d ) After 3 minutes have elapsed, the water temperatike gage should indicate 180 degrees F.

( e ) Turn off the power supply and disconnect the test circuit.

(5) Fuel Level gage test.

( a ) Connect the positive lead of a variable voltage dc power supply adjusted for 28.5 Vdc, to pin small w of receptacle J1.

( b ) Connect the negative lead of the power supply via a 0-50 ohm 100 watt potentiometer adjusted for 15 ohms to pin X of receptacle J1.

minutes.

( c ) Turn on the prover supply and wait 3

( d ) After 3 minutes have elapsed, the fuel level indicator should indicate one-half tank

( e ) Turn off the power supply and disconnect the test circuit.

(6) Total Time indicator test.

(8) Connect the positve lead of a variable voltage dc power supply adjusted for 28.5 Vdc , to pin small w of receptacle Jl.

( b ) Connect the negative lead of the power reapply to pin small r of receptacle J1.

( c ) Turn on the power supply.

( d ) Observe the tenths column of the indicators digital read out.

( e ) The indicadicator shall display one-tenth after six finutes of operation.

(f) Turn off the power supply and remove the test leads.

3-7

(7) Panel light test.

( a ) Connect the positive lead of a variable voltage dc power supply, adjusted for 24 Vdc, to pin small v of receptacle J1.

( b ) Connect the negative lead of the power supply to pin small r of receptacle Jl

( c ) Place the PANEL LIGHT switch to the

ON position and observe the illumination of three panel lights.

( d ) Place the PANEL LIGHT switch to the

OFF position.

( e ) Turn off the power supply and disconnect the test leads.

(8) Air cleaner condition light test.

( a ) Connect the positive lead of a variable voltage de–power supply, adjusted for 24 Vdc to pin small c of receptacle J1.

( b ) Connect the negative lead of the power supply to pin small r of receptacle J1.

( c ) Turn on the power supply.

( d ) The AIR CLEANER CONDITION light does not illuminate.

( e ) Depress the AIR CLEANER CONDITION light, the light illuminates.

( f ) Turn off the power supply and connect the position lead to pin small u of receptacle J1.

( g ) Turn on the power supply.

( h ) The AIR CLEANER CONDITION light illuminates.

( i ) Turn off the power supply and disconnect the test leads.

(9) Circuit breaker light test.

( a ) Connect the positive lead of a variable voltage dc power supply, adjusted for 24 Vdc, to pin small v of receptacle Jl.

( b ) Connect the negative lead of the power supply to Fin small r of receptacle Jl.

( c ) Turn on the power supply.

( d ) The CKT. BRKR. light does not illuminate.

(e) Depress the CKT. BRKR. light, the light illuminates.

(f) Turn off the power supply and connect the position lead to pin small a of receptacle J1.

3-8

( g ) Turn on the power supply.

( h ) The CKT. BRKR. light illuminates.

( i ) Turn off the power supply and disconnect the test leads.

(10) Battle short light test.

( a ) Connect the positive lead of a variable voltage dc power suppy adjusted for 24 Vdc, to pin small v of receptacle J1.

( b ) Connect the negative lead of the power supply to pin small r of receptacle J1.

( c ) Turn on the power supply.

( d ) The BATTLE SHORT light does not illuminate.

( e ) Depress the BATTLE SHORT light, the light illuminates.

( f ) Turn off the power supply and connect the position lead to pin R of receptacle J1.

( g ) Place the BATTLE SHORT switch to the ON position, the BATTLE SHORT light illuminates.

( h ) Place the BATTLE SHORT switch to the OFF position.

( i ) Turn off the power supply and disconnect the test leads.

(11) Synchronizing lamp test

( a ) Connect one lead of a 120 Vac power supply to pin J of receptacle J1.

( b ) Connect the remaining lead of the power supply to pin G of receptacle J1.

( c ) Turn on the power supply.

( d ) Place the unit operation switch to the

PARALLEL position.

( e ) One of two synchronizing lamps (DS4) shall illuminate.

( f ) Place the unit operation switch to the single unit position.

( g ) Turn off the power supply and disconnect the test leads.

( h ) Repeat the procedure b (11) (a) through

(g) for the-second synchronizing lamp (DS5) utilizing pins K and H of receptacle J1.

(12) DC ammeter test

(a) Connect a Simpson 260 or equivalent

ohmmeter, with the R x 10,000 scale selected, to pins Z and Y of receptacle J1.

( b ) With the positive lead connected to pin

Y and the negative lead to pin Z, the ammeter will read approximately 6 amperes up scale.

( c ) Reverse the connections at receptacle

J1 so that the positive lead is connected to pin Z and the negative lead is connected to pin Y.

( d ) The ammeter will read approximately

6 amperes down scale.

( e ) Disconnect the ohmmeter and test leads.

(13) Voltage adjusting rheostat test

( a ) Connect a Simpson 260 or equivalent ohmmeter; with the R x 100 scale selected, across pins small z and large U of receptacle J1.

( b ) Place the VOLTAGE SENSING switch to the LOCAL position.

( c ) Rotate the VOLTAGE ADJUST rheostat from stop to stop, the resistance will vary from 0 to 250 + 10 percent ohms,

( d ) Rotate the VOLTAGE ADJUST rheostat until 125 ohms are indicated on the ohmmeter and disconnect the test leads.

(14) Frequency adjust rheostat test

( a ) Connect a Simpson 260 or equivalent ohmmeter; with the R x 100 scale selected, across pins N and T of receptacle Jl. The resistance indicated should be 500 ohms ± 10 percent.

( b ) Remove the test lead from pin T and place it in pin M.

( c ) Rotate the FREQUENCY ADJUST rheostat from stop to stop, the resistance should vary from 0 to 500 ± 10 percent ohms.

c. Installation. Refer to Operator and Organizational Maintenance Manual and install the control cubicle.

3-9/(3-10 blank)

4-1. General.

CHAPTER 4

HOUSING GROUP REPAIR INSTRUCTIONS

The engine generator set housing provides a protective enclosure during set operation or storage.

Doors permit sufficient access to all areas of the engine generator set for operating and routine maintenance procedures.

4-2. Housing Removal and Cleaning.

Refer to Operator and Organizational Maintenance

Manual.

4-3. Housing Inspection, Servicing, and Repair.

a. Refer to Operator and Organizational Maintenance Manual for inspection and servicing procedures.

b. Repair any minor covers, and panels.

sheet metal dents in doors, c. Sheet metal tears can be repaired by welding.

d. Paint scratches that reveal bare metal or paint that is removed during repair should be touched up as follows:

(1) Smooth edges of remaining paint with fine sandpaper.

(2) Clean area with Federal Specification P-

D-680 solvent and wipe dry with clean cloth.

(3) Treat area and paint in accordance with service requirements.

e. Replace any cover, door, panel, or hardware that is damaged beyond repair.

4-4. Housing Installation.

Refer to Operator and Organizational Maintenance

Manual.

4-1/(4-2 blank)

5-1. General.

Electrical interconnection of control devices and indicators is accomplished through wiring harnesses.

Wires in the harnesses are bundled and secured to prevent unnecessary movement and chafing, and to conserve space. Internal wiring harnesses for the relay boxes, kits and other electrical assemblies are also provided in this section.

5-2. Wiring Harness Removal and Inspection.

a. Refer to Operator and Organizational Maintenance Manual for harness removal procedures.

b. Refer cooperator and Organizational Maintenance Manual for inspection procedures.

5-3. Wiring Harness Repair and Rebuild.

a. Repair.

(1) Repair procedures for individual wires are covered in the Operator and Organizational Maintenance Manual.

(2) If a wiring harness has sustained damage to 30 percent or more of the wires in the harness, the wiring harness must be completely rebuilt.

Rebuild.

of the set.

(1) Figures 5-l through 5-40 are illustrations

wiring harnesses installed on the generator

(2) Each illustration includes a wire run list providing wire origination, destination, identification number, wire length, and preparation requirements, and end preparation. Find numbers

(circled) related to specific components.

CHAPTER 5

WIRING HARNESS REPAIR INSTRUCTIONS

(3) Refabricate anew wire harness using the illustration for dimension and the wire run list for proper wire connection.

(4) If a wiring harness cannot be identified, compare it with the illustrations until proper identifications made. Check numbers stamped on wires against those in the wire run list to insure proper identification before proceeding with refabrication.

(5) Wiring shall be neatly laced through the use of self-locking nylon straps, located at intervals not to exceed three inches, and also at each wire break out.

(6) Soldering shall be in accordance with requirement 5 of MIL-STD-454 using SN60 solder.

(7) Wire numbering shall be in accordance with MIL-W-5088, except that length between adjacent groups of numbers shall not exceed six inches.

(8) Cut insulation tubing in one-half inch pieces and install around wires at pins of connectors and receptacles.

(9) Install nylon filler plugs MS25251-16 in unused openings of connectors.

5-4. Installation.

Refer to Operator and Organizational Maintenance

Manual for installation procedures.

5-1

5-2 Change 1

Figure 5-1. AC Power Control 50/60 Hz Wiring Harness

Figure 5-2. AC Power Control 400 Hz, Wiring Harness (Sheet 1 of 2)

Change 1 5-3

5 - 4

Figure 5-2. AC Power Control 400 Hz, Wiring Harness (Sheet 2 of

2 )

ange 1 5-7

Figure 5-4. DC Power Cables Wiring Harness (Sheet 1 of 2)

ME 6115-545-34/5-4(1) C1

5-8 Change 1

Figure 5-4. DC Power Cables Wiring Harness (Sheet 2 of 2)

ME 6115-545-34/5-4(2) Cl

(DELETED)

Change 1 5-9

5-10

Figure 5-6. Convenience and Paralleling, Wiring Harness (Sheet 1 of 2)

Figure 5-8. Fault Indicator Panel, Interconnecting Wiring Harness

5-15

5-16

Figure 5-9. Control Cubicle, Interconnecting Wiring Harness (Sheet 1 of 2)

Figure 5-9. Control Cubicle, Interconnecting Wiring Harness (Sheet 2 of 2)

5-17/(5-18 blank)

Figure 5-11. Special AC Power Cables

Change 1 5-25/(5-26 blank)

Change 1 5-29

Figure 5-13.

Current Transformer Assembly Mode II Sets Wiring Harness

ME 6115-545-34/5-13 Cl

5-30

Figure 5-14.

Electric Governor Control (Class 1 Mode I) Sets, Wiring Harness (Sheet 1 of 2)

Figure 5-14.

Electric Governor Control (Class 1 Mode I) Sets, Wiring Harness (Sheet 2 of 2)

5-31

5 - 3 2

Figure 5-15. Electric Governor Control (Class 1 Mode II) Sets, Wiring Harness

Figure 5-16.

Electric Governor Control To Actuator Wiring Harness, Class 1 Sets

5-33

5-34

Figure 5-17.

Electric Governor Control To Actuator Class 1 Sets Feedback Cable

Figure 5-20. Tactical Relay Assembly, Interconnecting Wiring Harness

5 - 3 9

5-40 Change 4

Figure 5-21. Load Bank Interconnect, Tactical Relay

Figure 5-23.

Precise Relay Assembly (Class 1 Mode I) Sets, Wiring Harness

5-43/(5-44 blank)

Figure 5-25. Excitation System Assembly Interconnecting Wiring Harness

5-47

5-48 Change 1

Figure 5-26.

Voltage Regulator Wiring Harness

ME 6115-545-34/5-26 Cl

TM 5-6115-545-34

Figure 5-27. Set Special Relay Assembly (Class 1, Mode I) Sets. Wiring Harness (Sheet 2 of 5)

ME 6115-545-34/5-27(2)

5-51

TM 5-6115-545-34

5-52 Change 8

Figure 5-27. Set Special Relay Assembly (Class 1, Mode I) Sets, Wiring Harness (Sheet 3 of 5)

Figure 5-27.

Set Special Relay Assembly (Class 1, Mode I) Sets, Wiring Harness (Sheet 4 of 5)

Change 1 5-53

ME 6115-545-34/5-27(5)

5-54

Figure 5-27. Set Special Relay Assembly (Class 1, Mode I) Sets, Wiring Harness (Sheet 5 of 5)

TM 5-6115-545-34

Figure 5-28. Set Special Relay Assembly (Class 1, Mode II) Sets, Wiring Harness (Sheet 2 of 5)

Change 8 5-57

TM 5-6115-545-34

5-58 Change 8

Figure 5-28. Set Special Relay Assembly (Class 1, Mode II) Sets, Wiring Harness (Sheet 3 of 5)

Figure 5-28. Set Special Relay Assembly (Class 1, Mode II) Sets, Wiring Harness (Sheet 4 of 5)

Change 1 5-59

5 - 6 0

Figure 5-28. Set Special Relay Assembly (Class 1, Mode II) Sets, Wiring Harness (Sheet 5 of 5)

Figure 5-29.

Load Measuring Unit Interconnecting, Wiring Harness

5-61/(5-62 blank)

5-65

Figure 5-30.

Engine Accessories, Wiring Harness (Sheet 2 of 3)

M E 6 1 1 5 - 5 4 5 - 3 4 / 5 - 3 0 ( 2 )

5-66

Figure 5-30. Engine Accessories, Wiring Harness (Sheet 3 of 3)

ME 6115-545-34/5-30(3)

Figure 5-31. Paralleling Cable Assembly

5-67

5-68

Figure 5-32.

Fuel Burning Winterization Kit, Wiring Harness

Figure 5-33.

Fuel Burning Winterization Control, Wiring Harness

ME 6115-545-34/5-33

5-69

5-70

Figure 5-34.

Electric Winterization Kit, Wiring Harness (Sheet 1 of 2)

6115-545-34/5-34(1)

5-71

Figure 5-34.

Electric Winterization Kit, Wiring Harness (Sheet 2 of 2)

ME 6115 545-34/5-34(2)

5-72 Change 1

ME 6115-545-34/5-35(1) Cl

Figure 5-35. Electric Heater Control Box, Wiring Harness (Sheet 1 of 2)

ME 6115-545-34/5-35(2)

Figure 5-35. Electric Heater Control Box, Wiring Harness (Sheet 2 of 2)

5-73/(5-74 blank)

Figure 5-36. Load Bank, Wiring Harness (Sheet 2 of 3)

Change 4

5-77

5-78

Change 4

Figure 5-36. Load Bank, Wiring Harness (Sheet 3 of 3)

5-79

Figure 5-37.

Load Bank Capacitor (Sheet 1 of 2)

5-80

Figure 5-37.

Load Bank Capacitor (Sheet 2 of 2)

Figure 5-38. Load Bank Control Panel, Wiring Harness (Sheet 1 of 2)

5-81

5-82

Figure 5-38. Load Bank Control Panel, Wiring Harness (Sheet 2 of 2)

Figure 5-39. Special Purpose Cables Assembly - 70-1274 for Generator

Set to Load Bank Main Power Cable

Change 6

5-83

5-84

Figure 5-40. RFI Capacitors, Wiring Harness

CHAPTER 6 LOAD CONNECTION GROUP REPAIR INSTRUCTIONS

Section I. INTRODUCTION

6-1. Scope.

This chapter contains repair instructions for the main load contactor and current transformer of the load connection group.

6-2. Load Connection Group Description.

a. The load connection group consists of the main load contactor, load terminal board assembly, current transformer assembly, and reconnection board.

b. The main load contactor connects the main generator output to the load. The contactor closes when the load contactor switch (S-3) (refer to Operatar and Organizational Maintenance Manual) is placed in the on position momentarily.

c. The load terminal board provides a means of connection to the generator set load. The contactor connects the generator output to the load through the load terminal board.

d. The output cables of the generator pass through the cores of the current transformers. When the generator is connected to a load, a proportional current is induced in the current transformer secondary.

This secondary current is used by the excitation system as a current boost during a short circuit and cross current compensation during parallel operation

The current transformer secondary is also used to operate the ammeter and wattmeter circuits in the control panel and it is used in the load measuring unit circuit.

e. The reconnection board permits reconnection of the generator phase windings to give optional output voltages. Both ends of each coil of each phase winding run from the generator to a stud on the reconnection board. A changeover board, with copper bus bars, is mounted so that the studs contact the bus bars. The bus bars are so designed that by moving the changeover board to one of two positions, the generator phase coils may be connected in series or parallel for 120/208 volt or 240/416 volt operation f. Refer to the Operator and Organizational Maintenanance Manual for maintenance instruction procedures covering the load terminal board and reconnection board.

Section II. MAIN LOAD CONTACTOR

6-3. Removal and Disassembly.

a. Removal. Refer to Operator and Organizational Maintenance Manual and remove the main load contactor.

b. Disassembly.

See figure 6-1 or figure 6-1 D

(used on Serial Numbers FZ-01639 on, for 50/60 Hz and Serial Numbers FZ-06463 on, for 400 Hz) and disassemble the main load contactor as illustrated.

6-4. Cleaning, Inspection, and Testing.

a. Cleaning.

Clean all components with cloth dampened in cleaning solvent, Federal Specification

P-D-680.

b. Inspection.

Refer to Operator and Organizational Maintenance Manual.

c. Testing. Refer to Operator and Organizational

Maintenance Manual.

6-5. Repair.

b. Replace contacts in contactor if badly pitted or burned. When one contact is damaged, all contacts must be replaced.

c. Repair damaged threads with a die or by filing with a fine mill file.

6-6. Reassembly and Installation.

Reassembly.

See figure 6-1 and reassemble

the-main load contactor observing the following:

(1) After assembly of the operator assembly

(23) refer to figure 6-1A and perform the

following adjustment procedures:

Change 3 6-1

6-2 Change 1

10.

11.

12.

13.

14.

15.

Plate

Screw

Washer

Cover

Screw

Washer

Screw

Washer

Cover assy

Contactor assy

Gasket

ME 6115-545-34/6-1(1) Cl

Figure 6-1.

Main Load Contactor

(Sheet 1 of 3)

Figure 6-1.

Main Load Contactor

(Sheet 2 of 3)

16. Screw

17. Washer

18. Washer

19. Chamber

20. Gasket

2 1 . N u t

22. Washer

23. Operator assy.

24. Ring, retaining

25. Bushing, locating

26. Spring

27. Shim

28. Shim

29. Shim

30. Bridge assy.

31. Operator

32. Bushing, adjusting

3 3 . N u t

34. Washer

35. Washer

36. Screw

37. Washer

38. Base assy.

3 9 . N u t

40. Washer

41. Washer

42. Contact assy.

4 3 . A r c c h u t e

44. Grommet

45. Spacer

46. B a s e

ME 6115-545-34/6-1(2) Cl

Change 1 6-3

47. Screw

48. Screw

49. Washer

50. Washer

51. Clamp

52. Connector aux.

contact assy.

53. Connector and wire assy.

54.

55.

56.

57.

58.

59.

60.

61.

Connector 62.

Aux. contact assy 63.

Au. contact assy 64.

Screw

Washer

Switch

Screw

Washer

65.

66.

67.

68.

69.

Washer

Bracket

Actuator assy

Nut

Washer

Terminal

Rod

Spring

74.

75.

76.

77.

70.

71.

72.

73.

Operator a

SS y

Nut

Washer

Screw

Bracket

Nut

Washer

78.

79.

80.

81.

82.

83.

84.

85.

86.

Operator aux.

Core and rod

Screw

Washer

End Plate

Washer

Coil

Core and frame

ME 6115-545-34/6-1(3) C1

Figure 6-1. Main Load Contactor

(Sheet 3 of 3)

6-4 Change 1

(a) Check each individual contact at its edge (insert A) with a force gauge. Preload should be between 1-1/2 -2 1/2 lbs. This can be attained

by adding or removing shim (see chart, figure 6-1A).

(b) Preload is checked by the initial

breakaway of the E ring at point B, figure 6-1A.

Preload should be between 1-1/2 to 2-1/2 lbs. This can be obtained by adding or removing shim (See

chart, figure 6-1A).

(2) After assembly of the actuator assembly

(64, figure 6-l), refer to figure 6-lB and per-

form the following adjustment procedures

(a) Leave four screws (1) loose.

(b) Clamp assembly at points A and B to assure no-air gap at points C and D.

(d) Remove clamp.

(e) Insert feeler gauge (0. 150 + 0.010 in.) into movable core gap and adjust guide screws (2) evenly until gauge is snug throughout the parimeter.

(f) Secure after adjustment by tightening two nuts (3).

(3) Contactor adjustment.

(a) Contact overtravel. Refer to figure

6-lC and proceed as follows:

(1) Attach indicator lamp on ohmeter to terminal A1-A2 & C1-C2.

(2) Insert 0.035 gauge into movable core cap (A).

(3) Apply 24 VDC to coil.

(4) Adjust carrier bushings at point (B) until continuity is made on A1-A2 & C1-C2.

(5) Secure by tightening nuts (l).

(6) Recheck continuity at 0.035. No continuity at 0.040 readjust if necessary.

(b) Economizing switch. Refer to figure

6-lC and proceed as follows:

(1) Adjust switch bracket (3) to transfer switch. Check that white button is fully depressed and allow approximately 0.010 clearance between white button and tap operator (point C).

Secure screws on bracket.

(2) Insert 0.010 gauge into movable core gap (A).

(3) Apply 24 VDC to coil.

(4) Adjust lower tap (D) by bending to transfer switch.

(5) Recheck

0.010 gauge transfer

0.018 gauge no transfer

Readjust if necessary

and proceed as follows:

(1) Before adjustment, set lift comb item

(5) so that the deflector on the guide leaf springs

(6) are near equal in energized and de-energized position. Secure by tightening nuts (4).

(2) Normally closed. Insert 0.018

guage between guide rod head and operator plate,

(point D 2 places).

Adjust stationary contacts to just touch the movable contact (use indicator light) recheck with 0.025 gauge at point (D). No continuity.

Readjust if necessary.

(3) Normally Open. Same as normally closed except shims are inserted into movable core gap (point A).

Change 1 6-4A

Figure 6-lA Operator Assembly- Main Contact Adjust Procedure

6-4B Change 1

Figure 6-1B. Actuator Assembly Adjustment Procedure

Figure 6-1C. Contactor Adjustment

Change 8 6-4C

1. Identification plate

2. Wiring diagram plate

3. Screw

4. Lock washer

5. Flat washer

6. Shield

7. Contactor subassy

8. Screw

9. Lock washer

10. Screw

11. Lock washer

12. Flat washer

13. Screw

14. Lock washer

Figure 6-lD. Main Load Contactor (Sheet l of 3)

15.

16.

17.

18.

19.

20.

Cover

Switch-Connector assy

Aux switch

Connector

Gasket

6-4D Change 8

21.

Locking spacer

22.

Lock washer

23. Flat washer

24.

Chamber

25. Gasket

26.

Nut

27.

Lock washer

28. Flat washer

29.

Base assy

30.

Screw

31.

Lock washer

32.

Flat washer

33.

Flat washer

34.

Nut

35. Bus bar

36.

Insert

37.

Base

38.

Gasket

39. Nut

40.

Lock washer

41.

Flat washer

42.

Spacer

43.

Bushing

44.

Bushing

45. Bridge assy

46.

Housing

47.

Bridge

48.

Spring

49. Bushing

50. Arc chute

51. Screw

52. Lock washer

53.

Metallic washer

54.

Insulation

55.

Detent

Figure 6-lD. Main Load Contactor (Sheet 2 of 3)

Change 3 6-4E

56.

57.

58.

59.

60.

61.

62.

63.

64.

65.

66.

67.

Operator

Screw

Lock washer

Screw

Lock washer

Nut

Spring

Solenoid subassy

Moveable core-rod assy

Lock washer

Nut

68. Rod

69. Core assy

70. Stud

71. Operator

72. Frame-core assy

73. Frame assy

74. Screw

75. Flat washer

76. Frame

77. Screw

78. Lock washer

79. Flat washer

80. Frame

81. Frame

82. Screw

83. Flat washer

84. Micro switch assy

85. Screw

86. Lock washer

87. Flat washer

88. Switch

89. Bracket

90. Plate

91. Coil

Figure 6-1D. Main Load Contactor (Sheet 3 of 3)

6-4F Change 8

Section III. CURRENT TRANSFORMER

6-7. On Equipment Test.

a. The following resistance readings should be precent for good current transformers. Use a Simpson 260 or equivalent meter, (properly zeroed) with the R x 1 scale selected for making the measurements.

b . Current transformer secondary resistance

readng. (fig. 6-2)

Percent of

Rated Load

Meter

CT1 . . .

CT2 . . .

CT3 . . .

2.5 ohms same as CTl same as CTl

LMU

CT4 . . .

CT5 . . .

CT6. . .

0.2 ohms pins 1 to 3, 0.1

ohm center pin to 1 and center pin to same as CT4

3 same as CT4

Cross Current

Compensation

CT7 . . .

0.5 ohms pins l and 2

6-8. Removal and a . Removal

Disassembly.

(1) Remove and tag the generator output leads and pass them through the associated current transformers freeing the current transformer assembly

for removal. (fig. 6-2)

(2) Remove the generator harness wiring from terminal block TB16, identifying each lead with the terminal block post number from which it was removed.

(3) Remove the current transformer assem-

bly (7, fig. 6-3) by removing hardware items 3,

4 and 5.

b . Disassembly.

See figure 6-4 and disassemble

the current transformer as illustrated.

Figure 6-2. Routing Main Generator Leads Through Current Transformers

Change 1 6-5

6-6 Change l

Figure 6-3. Current Transformer Assembly and Load Connecting Group Mounting Brackets

Figure 6-4. Current Transformer Assembly

Change 1 6-7

6-9. Cleaning, Inspection, and Testing.

a . Cleaning. Clean all components with a cloth dampened in cleaning solvent, Federal Specification

P-D-680.

b . Inspection. Refer to Operator and Organizational Maintenance Manual.

(1) To test CTl, CT2, and CT3 on either Mode

I or Mode II sets, proceed as follows:

(a) Wrap 10 turns of a conductor around the coils of cm.

(b) Apply an ac current of 10 amperes to the conductor.

(d) Repeat steps (a) through (c) on CT2 and

CT3. Measure CT2 at terminals B1 and B2; measure CT3 at terminals Cl and C2.

(2) To test CT4, CT5, and CT6 on either Mode

I or Mode II sets, proceed as follows

(a) Apply 20.7 volts (rms) 60 Hz across terminals l and 3.

(b) Voltage between terminals 1 and 2 shall measure 16. 5 ± 1 percent Vac.

36 ma.

(d) Apply 50 amperes 60 Hz through 1 primary turn.

Secondary current should be 180 ma

± 1% at terminals 1-3.

(3) To test CT7 on Mode II sets, proceed a follows:

(a) Apply 15 volts (rms) 400 Hz across, terminals 1 and 2.

(b) The excitation current shall be less than

45 ma (rms).

Secondary current should be 250 ma

± 1%.

(4) To test CT7 on Mode I sets, proceed as follows:

( a ) A p p l y 1 5 v o l t s ( r m s ) 6 0 l b a c r o s s t e r - minals 1 and 2.

(b) Excitation current shall be less than

60 ma (rms).

Secondary current should be 250 ma

± 1%.

6-10.

Repair.

Replace defective current transformers.

Replace worn grommets.

Replace all gaskets with new ones.

6-11.

Reassembly and Installation.

a. Reassembly

See figure 6-4 and reassemble

the current transformer assembly.

b. Installation. See paragraph 6-8 and install the

current transformer assembly.

6-8 Change 1

CHAPTER7

ELECTRO-HYDRAULIC GOVERNING SYSTEM

(CLASS I, PRECISE SETS ONLY)

7-1. General a . The electro-hydraulic governing system is a speed (frequency) sensing stem used to maintain prime mover speed constant and therefore generator output frequency, during periods of unchanging load and when load additions or deletions occur.

b . The system consists of a control unit, load measuring unit and hydraulic throttle actuating unit.

c . The control unit inputs are the generator output voltage, and a dc voltage (0-9. 8 Vdc) proportional to the generator load, supplied by the load measuring unit.

The generator voltage input is applied to a frequency sensing network and reference voltage network, The differ ential output of these two networks determines the control current of two magnetic amplifiers whose outputs drive separate coils of the hydraulic actuators pilot valve. The actuator pilot valve positions the actuator power piston which is connected to the input arm of the fuel injection pump. The actuators hydraulic system is comprised of a reservoir, engine driven pump (300-320 psi, 2 gpm), cooler and filter.

d. Any deviation of engine speed, reflected as a change in frequency at the input of the governor, produces a change in the magnitude and direction of magnetic amplifier control field current. This change in ccntrol field current will increase the strength of one coil of the pilot valve while decreasing the strength of the other,

The resultant difference repositions the pilot valve in turn repositioning the power piston which changes the output of the fuel injection pump, changing engine speed and consequently restoring generator frequency to its nominal value.

The load measuring units (LMU) input to the governor control provides for automatic load sharing when two or more sets are operated in parallel.

Each set is equipped with an LMU.

f. If the load added to the system is not equally divided, the LMU inputs to their respective governors will differ. The resulting difference acting through additional windings of each sets governor

(which are all connected in parallel) will reposition each sets actuator power piston such that fuel flow in the more heavily loaded set is decreased while that of the lightly loaded set is increased. Since the power input of each prime mover has been readjusted, equal division of true power (Kw) occurs with no deviation in frequency of any set.

7-2. Malfunction.

The following procedures are to be performed in the generator set unless otherwise specified.

a. If the FL - NL or NL - FL transient exceeds

1-1/2 percent of rated speed and/or does not re establish stable engine operating conditions within one second, realign the control unit in accordance

with paragraph 7-8 .

Also follow this procedure if the engine speed hunts. If the set cannot be stabilized, check sockets A and B of plug P-21

(refer to Operator and Organizational Maintenance

Manual) for 24 Vdc (A is positive).

b. If the engine speed increases to above nominal operating speed, check sockets A and B of P-17 for

120 Vat. If it is missing, troubleshoot the generator set wiring. (Refer to Operator and Organizational

Maintenance Manual). If it is present, check the resistance of the frequency adjusting circuit consisting of R4 (250 ohms) rheostat R1 frequency adjust

(500 ohms) and R5 (250 ohms) fixed resistor.

Refer to Operator and Organizational Maintenance

Manual.

Measure the total circuit resistance across N and T of harness plug P17. The circuit resistance should be 1000 ohms (5 percent tolerance).

After testing for correct total resistance, test the operation of the frequency adjust rheostat by connecting an ohmmeter across pins M and T and revolving the frequency adjust rheostat through its entire travel. The resistance should vary from

750 ohms to 250 ohms. Repeat this procedure using the ohmmeter across pins M and N of the harness plug.

If the problem persists, check sockets

A and B of plug P-21 for 24 Vdc (A is positive).

c, If the engine speed remains below the nominal operating speed, adjust R1. If there is no improvement, check the resistance of the frequency adjust circuit. Disconnect P-17 and check the resistance of the frequency adjust circuit consisting of R4 (250 ohms) fixed resistor, R1 frequency adjust rheostat (500 ohms) and R5

(250 ohms, 5 percent) fixed resistor. Refer to

Operator and Organizational Maintenance Manual.

Measure the total circuit resistance across N and T of harness plug P17.

The circuit resistance should be 1000 ohms (5 percent tolerance). After testing for correct total resistance, test the operation of the frequency adjust potentiometer by connecting an ohmmeter across pins M and T and revolving the frequency adjust potentiometer through its entire travel. The resistance should vary from 750 ohms to 250 ohms.

Repeat this procedure using the ohmmeter across pins M and N of the harness plug.

Disconnect actuator electrical connector before making this measurement. Push actuator piston all the way down and adjust engine speed with manual throttle. If this value resistance is measured, check sockets A and B at plug P-21 for 24 Vdc (A is positive).

d. If the set is operating at a constant load and voltage and during an eight-hour period the change in ambient temperature does not exceed 60°F, the set frequency should not drift beyond 1/2 of one percent of rated frequency. The above requirement assumes that the set temperatures were stabilized

7-1

at the initial and final ambient temperatures.

NOTE

If the drift in paragraph d is excessive, realign the control unit following the procedure out-

lined in paragraph 7-8.

e. At constant ambient temperature, constant load, constant voltage and constant barometric pressure, the set frequency should remain within a bandwidth of 1 percent of rated frequency for a period of 4 hours.

If this bandwidth has been exceeded, realign the

control unit in accordance with paragraph 7-8.

f. If the preceding solutions to the specific problem do not resolve the problems, replace and

repair the control unit, actuator (para 13-3 thru

13-8) or load measuring unit (para 8-15 thru

8-19) as required.

7-3. Removal.

Refer to figure 7-1 and remove in the order of

sequence numbers.

7-4. Disassembly and Repair a. Disassemble electric governor control unit,

if required, as illustrated in figure 7-2.

NOTE

Disassembly and repair of electric governor control unit at the field level is restricted to removal of the cover, connectors, potentiometers and test jacks.

further disassembly requires unpotting and the following disassembly can be performed by depot maintenance personnel only.

b. Remove cover and components installed on cover in the order of sequence numbers (1 thru 15).

NOTE

Tag and unsolder wires for the components on the cover.

(1) Replace defective test jacks, potentiometers or connectors.

(2) Repair procedures for individual wires of a wiring harness are covered in the Operator and

Organizational Maintenance Manual.

Remove six screws and lockwashers from cover of control unit.

Lift cover slightly and set at a slight angle to keep the connectors out of the potting compound.

and potentiometers d. Place the complete unit in a trolled oven, large enough to allow completely around the unit.

temperature conair to circulate

7-2

CAUTION

The melting temperature of the potting compound is 165 F. The flash point is 515°F. Do not unpot by placing unit on a hot plate type surface or by using an open flame.

e. Set the oven temperature at 180°F to 185°F and allow the unit to soak until the potting compound is melted.

The normal soak period at this temperature is 11 to 12 hours.

WARNING

Use care when handling the hot potting compound. It can cause severe injury to personnel.

f. Using heavy gloves and wearing safety glasses, remove the printed circuit board from the melted putting compound. Lift the board s1owly, allowing the potting compound to drain off the components.

g. Set the printed circuit board with transformers on the bottom on a drain board and allow it to cool to room temperature.

h. Remove screw (4) and lockwashers (5) which attach connectors (P1, J3, P5, P2) to cover.

i. Tag wiring and remove harness (6).

j. Disassemble remaining components mounted on cover in accordance with index numbers 7 through

27.

7-5. Cleaning and Inspection.

a. Clean all parts with a cloth dampened in cleaning solvent Federal Specification P-D-680 and dry thoroughly.

b. Inspect for cracks, breaks, damaged connectors, damaged terminals, defective wiring, and defective components.

Check potentiometer for continuity, resistance, and wiring for open insulation.

7 - 6 .

Tests and Repair.

a. Perform test as outlined in figures 7-3 thru

7-10.

NOTE

Mount circuit card as shown in

figure 7-11 prior to test.

b. Resistance Test (50/60 Hz) . Refer to Table

7-1 and perform resistance test.

c. See figure 1-4 and 1-5 for schematic diagrams.

d. See table 7-2 for values of individual comp-

onents. When measuring individual components, disconnect at least one lead to prevent feedback readings.

Figure 7-1.

Electric Governor Control Unit Removal

Change l 7-3

7-4 Change 1

Figure 7-2. Electric Governor Control Unit

Connection

T-N (T +)

M-N (M +)

(M +)

F-N (F +)

(F+)

E-G (E +)

R-G (R+)

F-G (F +)

J-H (J +)

T-P (T +)

(T+)

U-S (U+ )

Table 7-1.

Resistance Test (50/60 Hz)

Potentiometer

Position

Nominal

Resistance

5100

R18CCW

R16CCW

Rl5CCW

6500

5500

120

650

2180

12180

6000

31000

LESS THAN 0.2 OHMS

Allowance resistance range (ohms)

3400-6800

1950-2400

11000-13000

5000-7000

30000-32000

5500-7500

4500-6500

100-140

550-750

R14CCW

2200

2600

525

1400-3000

1800-3400

450-600

USING M1, MEASURE RESISTANCE OF EACH PIN (ALL CONNECTORS) AND

EACH TEST POINT TO GOVERNOR CONTAINER. RESISTANCE SHOULD BE

INFINITY ON 100,000 OHM SCALE REPEAT FOR REVERSE POLARITY

RESISTANCE SHOULD BE INFINITY ON 100,000 OHM SCALE.

MAGNETIC AMPLIFIER BIAS TEST

TURN R1l, R12, R14, R15, R16, R18

FULL CW.

CONNECT GOVERNOR CONTROL UNIT TO

TEST EQUIPMENT AS SHOWN.

ALMOST R11 AND Rl2 FOR BALANCED

READING OF 450 MA ON M2 AND M3.

TURN R12 FULL CW. M2 AND M3 SHALL

READ 0-300 MA, AND BE BALANCED

WITHIN 50 MA.

TURN R12 FULL CCW. M2 AND M3 SHALL

READ 600-1000 MA, AND BE BALANCED

WITHIN 50 MA.

READJUST Rll AND Rl2 FOR BALANCED

READING OF 450 MA ON M2 AND M3.

LOCK Rll AND Rl2 FOR REMAINDER OF

TEST.

ME 6115-545-34/7-3

Figure 7-3.

Electric Governor Control Unit, Magnetic Amplifier

Bias Test (50/60 Hz)

Change 1 7-5

FREQUENCY SENSING CHECK (HIGH AND LOW

FREQUENCY)

CONNECT GOVERNOR CONTROL UNIT TO

TEST EQUIPMENT AS SHOWN

TURN Ra SO THE Resistance BETWEEN

P1-M AND Pl-T IS 250 OHMS.

REDUCE THE FREQUENCY OF THE AP-

PLIED 120 ± 2 VOLT SUPPLY UNTIL M2

AND M3 BALANCE.

THE FREQUENCY SHALL BE 57-58 Hz.

TURN Ra SO THE RESISTANCE BETWEEN

P1-M AND P1-N IS 250 OHMS.

INCREASE THE FREQUENCY OF THE AP-

PLIED 120 ± 2 VOLT SUPPLY UNTIL M2

AND M3 BALANCE.

THE FREQUENCY SHALL BE 64-65 Hz.

REF DES

Rb, R

M2., M3

QUANTITY

TEST EQUIPMENT

DESCRIPTION

POTENTIOMETER, 10 TURN, 500 OHM, 5 WATT

RESISTOR, FIXED, 250 OHM, 5 WATT

MILLIAMMETER, DC, 0-1000 MA

DC POWER SOURCE

AC POWER SOURCE

ME 6115-545-34/7-4 C1

Figure 7-4. Electric Governor Control Unit, Frequency Sensing Check (High and

Low Frequency) (50/60 Hz) e. Magnetic Amplifier Bias Test (50/60 Hz).

Refer to figure 7-3 and perform the magnetic ampli-

fier bias test.

f. Frequency Sensing Check, High and Low

Frquency (50/60 Hz). Refer to figure 7-4 and

perform the frequency sensing check.

g. Rectifier Bridge, CR7 thru CR30 and Feed-

back Winding Test (50/60 Hz). Refer to figure 7-5

and perform the rectifier bridge and feedback winding test.

h. Parallel Winding Test (50/60 Hz). Refer to

figure 7-6 and perform the parallel winding test.

i. Resistance Test (400 Hz). Refer to Table 7-3

and perform resistance test.

j. Magnetic Amplifier Bias Test (400 Hz). Refer

to figure 7-7 and perform the magnetic amplifier bias

test.

k. Frequency Sensing Check, High and Low

Frequency (400 Hz). Refer to figure 7-8 and per-

form the frequency sensing check.

L Rectifier Bridge, CR7 thru CRl0 and Feed-

back Winding Test (400 Hz). Refer to figure 7-9

7-6 Change 1 and perform the rectifier bridge and feedback winding test.

m. Parallel Winding Test (400 Hz). Refer to

figure 7-10 and perform the parallel winding test.

n. Replace any component found to be defective during tests.

o. For wiring harness repairs, refer to Operator and organizational Maintenance Manual.

p. If wiring harness has sustained extensive

damage, refer to Chapter 5 for wiring harness

rebuilding procedures.

7-7. Assembly.

a. See figure 7-12 and assemble printed circuit

board. If any connections are opened or bared for test purposes, or if any defective components are replaced, the effected area and components must be coated with polyurethane resin to prevent oxidation or other corrosion .

The coating must be of a minimum thickness of 0.007 inches and air bubble entry into the applied polyurethane must be controlled so that the legibility of component coding and identification is not impaired. The polyurethane resin to be utilized will correspond to MIL-I-46058,

Component

R1, R1A, R15

R l l

R4, R8, R22

R37

R2, R10

R12, R18

R16

R14, R20

Parallel winding

Feedback winding

Frequency control winding

Table 7-2. Electric Governor Control Unit Component Values

50/60 Hz Unit

(ohms)

400 Hz Unit

(ohms)

500

5000

500

5000

Remarks

3.0% tolerance

5100

3.0% tolerance

5100

1250

10,000

25,000

3500

750

10,000

25,000

3.0% tolerance

Check for open

Bias control winding

3,000

Less than 1.0

(nominal )

Less than 1.0

(nominal)

Less than 1.0

(nominal)

Less than 1.0

(nominal)

3,000

Less than 1.0

(nominal)

Less than 1.0

(nominal)

Less than 1.0

(nominal)

Less than 1.0

(nominal)

Check for open

Grade S, Type PUR.

b. See figure 7-2 and reassemble control unit

components.

c. Reconnect cover to printed circuit board with wiring harness.

d. Place the container in a temperature controlled oven. Set oven temperature at 180 to 185°F and allow container to soak 11 to 12 hours or until potting compound is completely melted.

e. Prior to installing the printed circuit board, remove the container from the oven and make sure that insulation paper is positioned next to the container shell.

f. Using heavy gloves, and safety glasses slowly lower the printed circuit board into the potting compound,

WARNING

Use care not to splash hot potting compound om operating personnel. It can cause severe injury.

g. Position the printed circuit board and allow compound to cool.

h. When compound has cooled and is substantiality solid, install top cover and hardware.

7-8. Adjustment.

See figure 7-13 for location of adjustment and controls

and adjust electric governor according to the following procedures a .

S i n g l e S e t A d j u s t m e n t P r o c e d u r e s

(1) With engine not operating, set frequency adjust control (on control panel), R11, R14, R16, and

R18 to midpoint by turning full each way and approximating center.

Set RI 5 full counterclockwise and R12 approximately 1/4 clockwise.

(2) Start engine. Refer to Operator and Organizational Maintenance Manual for operating instructions. If engine hunts, perform following adjustments to stabilize operation

(a) If hunt is of high frequency and small amplitude; adjust R12 clockwise and/or R16 counterclockwise.

(b) If hunt is of low frequency and long amplitude; adjust Rl8 countercloclwise. If operation does not stabilize, turn R16 clockwise. It maybe necessary to adjust R12 counterclockwise in conjunction with R18 and R16 adjustments to stabilize operation.

Change 5

7 - 7

TEST EQUIPMENT

REF DES

QUANTITY

DESCRIPTION

Rf, Rg

Rh, Ri

M2, M3

RESISTOR, FIXED, 5000 OHMS, 1 WATT

RESISTOR

]

FIXED, B2 OHM, 10 WATT

RESISTOR FIXED, 15 OHMS, 5 WATT

RESISTOR, FIXED, 25 OHMS, 5 WATT

MILLIAMMETER, DC, 0-1000 MA

MILLIAMMETER, DC, ZERO CENTER,

10-0-10 MA

SWITCH, ROTARY, 3 POSITION, 1 POLE, 1 AMP

DC POWER SOURCE

AC POWER SOURCE

AUTOTRANSFORMER 2:1 RATIO

ME 6115-545-34/7-5

Figure 7-5. Electric Governor Control Unit, Rectifier Bridge and Feedback Winding Test

(50/60 Hz)

(3) Once the set has been stabilized, connect a 0 - 10 volt range dc voltmeter (high impedance type -2000 ohms per volt or more) across test points 3 and 4 with the positive lead at test point 4.

Adjust FREQUENCY ADJUST control to obtain operating frequency (400 W, or 60 Hz), and then adjust

R14 until volt e across test points 3 and 4 is zero volts, with no load on generator.

(4) Connect dc voltmeter across tests points 1 and 2 with positive lead at test point 1. Adjust R11 and the frequency adjust control until the dc voltmeter reads zero volts at nominal frequency. Repeat the adjustment until the voltage across test points 3 and 4 and across 1 and 2 is zero volts, and the set frequency is 50 Hz, 60 Hz or 400 Hz with no load on the engine. If test points 1 and 2 cannot be zeroed, they must be reduced to a minimum.

(5) Adjust RI 2 until a reading of approximately

4.5 volts is obtained across test points A and B, with no load on generator. If this voltage is too low, response will be sluggish and if it is too high, a rapid oscillation may occur.

causing oscillation,

Normal range is 3 to 6 volts.

(6) Adjust R18 clockwise as far as possible, and R16 counterclockwise as far as possible without

NOTE

Increasing the load measurement gain

R15 (turing in a clockwise direction) will improve transient performance; therefore it should be adjusted as high as possible. Transient performance must be checked using a frequency recorder.

7-8 Change 1

PARALLEL WINDING TEST

CONNECT GOVERNOR CONTROL

UNIT TO TEST EQUIPMENT AS

SHOWN.

M2 SHALL READ 0-300 MA.

M3 SHALL READ 600-840 MA.

REVERSE POLARITY OF CONNECT-

IONS TO PINS J1-E AND J1-G.

M2 SHALL READ 600-840 MA.

M3 SHALL READ 0-300 MA.

TEST EQUIPMENT

REF DES

M2, M3

QUANTITY

DESCRIPTION

RESISTOR, FIXED, 50,000 OHMS, 10 WATT

MILLIAMMETER, DC, 0-1000 MA

DC POWER SOURCE

AC POWER SOURCE

ME 6115-545-34/7-6

Figure 7-6. Electric Governor Control Unit Parallel Winding Test (50/60 Hz)

(7) The adjustment of R18 and R16 are interdependent.

For any position of R18 there is an optimum position for R16. Therefore, to improve transient performance, increase the frequent y gain by turning R18 clokwise. If hunt develops, readjust

R16 for stability. If no hunt develops, apply and reject load on the generator set to check for stability under transient conditions. Assuming that no hunt develops for an increase in frequency gain, (R18 turned clockwise) or that hunt can be removed by readjustment of R16, again increase frequency gain.

by turning R18 clockwise and note the transient performance. Finally a position may be reached where no readjustment of R16 can stabilize for the high frequency gain of R18. Then reduce the frequency gain to the stable region and optimize stability and performance with R16. The frequency gain should be reduced to a point where the system is not on the edge of instability for long-term stable operation.

(8) Transient performance improves as the frequency gain R18 is increased and the feedback gain R16 is a minimum for that particular position of frequency gain adjustment. If R16 is adjusted too far counterclockwise, there will be insufficient feedback to stabilize the operation at steady state.

If a slow oscillation occurs, turn R16 clockwise until stability is reached.

This is the optimum setting for the level of frequency gain.

(9) If R16 is turned far clockwise, a very fast oscillation may occur.

Turn R16 counterclockwise to the optimum point of stability.

b. Parallel Operation (Class 1 sets)

(1) Adjust in accordance with paragraph 16-11.

(2) If the sets will not divide load, or if they oscillate (successively interchange load) on the first attempt to parallel, check the polarity across pin

A and B of the parallel receptacle on both sets and verify, that the input circuits to pin C and D are correct and that the voltages are as specified.

7-9. Equipment Test

If the electric governor control has been renewed or

repaired, refer to Chapter 16, Section II and conduct

the following tests.

a. Frequency and voltage regulation, stability and

transient response test, short term. (para 16-15)

b. Frequency adjustment range test (para 16-16)

C h a n g e 1 7 - 9

Table 7-3. Resistance Test (400 Hz)

Connection

T-N (T +)

M-N (M +)

(M +)

F-N (F + )

(F +)

E-G (E +)

R-G (R + )

F-G (F +)

J-H (J+)

T - P ( T + )

(T +)

U-S (U +)

Potentiometer

Position

R18CCW

R16CCW

R15CCW

R14CCW

Nominal

Resistance

2550

1400

11480

4160

Allowable resistance range (ohms)

2 3 0 0 - 3 2 0 0

1200-1700

10000-12000

3500-5500

29160

4660

27000-31000

4000-5500

4500-6500 5500

120

650

100-140

550-750

1950

LESS THAN 0.2 OHMS

1400-2500

1500-2800

2150

520 450-600

USING Ml, MEASURE RESISTANCE OF EACH

TEST POINT TO GOVERNOR CONTAINER.

100,000 OHM SCALE. REPEAT FOR REVERSE

SHOULD BE INFINITY ON 100,000 OHM SCALE

PIN (ALL CONNECTORS) AND EACH

RESISTANCE SHOULD BE INFINITY ON

POLARITY. RESISTANCE

7-10

Change 5

MAGNETIC AMPLIFIER BIAS TEST.

TURN Rll, R12, R14, R15, R16,

R18 FULL CW.

CONNECT GOVERNOR CONTROL

UNIT TO TEST EQUIPMENT AS

SHOWN.

ADJUST Rll AND Rl2 FOR BAL-

ANCED READING OF 450 MA ON

M2 AND M3.

TURN R12 FULL CW. M2 AND M3

SHALL READ 0-300 MA, AND BE

BALANCED WITHIN 50 MA.

TURN R12 FULL CCW. M2 AND

M3 SHALL READ 600-1000 MA,

AND BE BALANCED WITHIN 50 MA.

READJUST Ml AND R12 FOR BAL-

ANCED READING OF 450 MA ON

M2 AND M3 AND LOCK Rll AND

Rl2 FOR REMAINDER OF TEST.

REF DES

M2, M3

TEST EQUIPMENT

QUANTITY

DESCRIPTION

MILLIAMMETER, DC, 0-1000 MA

DC POWER SOURCE

AC POWER SOURCE

ME 6115-545-34/7-7

Figure 7-7. Electric Governor Control Unit, Magnetic Amplifier Bias Test (400 Hz)

7-11

7-12

REF DES

Rb, RC

M2, M3

FREQUENCY SENSING CHECK (HIGH AND

LOW FREQUENCY)

CONNECT GOVERNOR CONTROL UNIT TO

TEST EQUIPMENT AS SHOWN

TURN Ra SO THE RESISTANCE BETWEEN

P1-M AND P1-T IS 250 OHMS.

REDUCE THE FREQUENCY OF THE AP-

PLIED 120 ± 2 VOLT SUPPLY UNTIL M2

AND M3 BALANCE.

THE FREQUENCY SHALL BE 375-380 Hz.

TURN Ra SO THE RESISTANCE BETWEEN

P1-M AND P1-N IS 250 OHMS.

INCREASE THE FREQUENCY OF THE

APPLIED 120 ± 2 VOLT SUPPLY UNTIL

M2 AND M3 BALANCE.

THE FREQUENCY SHALL BE 420-425 Hz.

TEST EQUIPMENT

QUANTITY

DESCRIPTION

POTENTIOMETER, 10 TURN, 500 OHMS, 5 WATT

RESISTOR, FIXED, 250 OHMS, 5 WATT

MILLIAMMETER, DC, 0-1000 MA

DC POWER SOURCE

AC POWER SOURCE

ME 6115-545-34/7-8

Figure 7-8.

Electric Governor Control Unit, Frequency Sensing Check (400 Hz)

REF DES

Rb, Rc

Rf, Rg

Rh, Ri

M2, M3

QUANTITY

TEST EQUIPMENT

DESCRIPTI0N

POTENTIOMETER, 10 TURN, 500 OHMS, 5 WATT

RESISTOR, FIXED, 250 OHMS, 5 WATT

RESISTOR, FIXED’ 5000 OHMS, 1 WATT

RESISTOR, FIXED, 50,000 OHMS, 10 WATT

RESISTOR, FIXED, 32 OHMS, 10 WATT

RESISTOR, FIXED, 15 OHMS, 5 WATT

RESISTOR, FIXED, 25 OHMS, 5 WATT

OHMMETER, 100,000 OHMS SCALE

MILLIAMMETER, DC, 0-1000 MA

MILLIAMMETER, DC, ZERO CENTER, 10-0-10 MA

SWITCH, ROTARY, 3 POSITION, 1 POLE, 1 AMP

GOVERNOR ACTUATOR, P/N 1321 7E5390

DC POWER SOURCE

AC POWER SOURCE

AUTOTRANSFORMER 2:1 RATIO

ME 6115-545-34/7-9

Figure 7-9.

Electric Governor Control Unit, Rectifier Bridge and Feedback Winding Test (400 Hz)

7-13

PARALLEL WINDNG TEST.

CONNECT GOVENOR CONTROL

UNIT TO TEST EQUIPMENT AS

SHOWN

M2 SHALL READ 0-300 MA.

M3 SHALL READ 600-840 MA.

REVERSE POLARITY OF CONNECT-

IONS TO PINS J1-E AND J1-G.

M2 SHALL READ 600-840 MA.

M3 SHALL READ 0-300 MA.

TEST EQUIPMENT

REF DES

QUANTITY

DESCRIPTION

M2, M3

RESISTOR, FIXED, 50,000 OHMS, 10 WATT

MILLIAMMETER, DC, 0-1000 MA

DC POWER SOURCE

AC POWER SOURCE

ME 6115-545-34/7-10

Figure 7-10. Electric Governor Control Unit, Parallel Winding Test (400 Hz)

7-14

Figure 7-11.

Electric Governor Control Unit, Test Position for Unpotted Units

Figure 7-12. Electric Governor Wiring Board Assembly (Sheet 1 of 2)

ME 6115-545-34/7-12 (1)

7-15

7-16 Change 1

Figure 7-12. Electric Governor Wiring Board Assembly (Sheet 2 of 2)

KEY to fig. 7-12

7 .

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

36.

37.

38.

39.

40.

30.

31.

32.

33.

34.

35.

Nut (2)

Lock washer (2)

Flat washer (2)

Screw

Transformer (T1)

Nut (2)

Washer (2)

Screw

Reactor (U)

N u t ( 2 )

Washer (2)

Screw (2)

Reactor (22) (L2)

Resistor (R5)

Capacitor (C7)

Resistor (R23)

Nut (2)

Washer (2)

Screws (2)

Transistor (Q1 & Q2)

Nut (2)

Washer (2)

Screw (2)

Washer (2)

Heat sink (2)

Reactor (L3)

Transformer (T2)

Rectifiers (CR3, CR4, CR5, CR6)

Capacitor (C9)

Resistor (R20)

Resistor (R22)

Nut (1)

Mug amp (ARl)

Nut (2)

Washer (2)

Board assy

46.

47.

48.

49.

50.

51.

52.

53.

54.

41.

4 2

43.

44.

45.

55.

56.

57.

58.

59.

60.

67.

68.

69.

70.

71.

72.

73.

74.

75.

61.

62.

63.

64.

65.

66.

76.

77.

78.

79.

80.

Resistor (R37)

Rectifiers (CR7, CR8, CR9, CRl0)

Capacitor (C2)

Board

Capacitor (C5)

Resistor (R4, R8)

Nut (2)

Washer (2)

Nut (2)

Studs (2)

Nut (1)

Washer (1)

Flat washer (1)

Screw (1)

Washer (2)

Resistor (R10)

Rectifiers (8)

Capacitor (C6)

Nut (2)

Washer (2)

Washer(2)

Screw (2)

Washer (4)

Resistor (1 & R1A)

Nut (1)

Washer (1)

Screw (1)

Washer (2)

Resistor (R2)

Rectifier (CR2)

Capacitor (C4)

Capaciitor (C3)

Board

Change 1 7-17

Figure 7-13.

Electric Governor Control Unit, Location of Adjustments and Controls

7-18 Change 8

7-10 GOVERNOR CONTROL UNIT (MEP-115A).

a. General.

(1) The electric governing system Is a speed

(frequency) sensing system used to maintain constant engine speed and generator output frequency during periods of unchanging load and when load additions or deletions occur. The system consists of a control unit, magnetic pickup and an electric throttle actuating unit. The engine speed signal is obtained from a magnetic pickup mounted in the flywheel housing in close proximity to the flywheel ring gear.

The frequency of the pickup signal is

proportional to engine speed. Figure 7-14 shows

the functional theory of operation.

(2) The control unit has four distinct circuits; pickup signal amplifier, frequency reference oscillator, phase comparator and output circuit.

(a) The Frequency Reference Oscillator is voltage controlled.

The frequency setting is adjusted by applying zero to 10 volts at the

Frequency Reference Oscillator input. The internal frequency adjust provides this voltage setting when the control unit is in operation. The Reference

Oscillator does not maintain a constant frequency.

It deviates from its nominal frequency as the engine speed changes during load changes. The Reference

Oscillator is forced by the Phase Comparator to track the amplified pickup signal representing engine speed.

The voltage representing speed error is the amount of voltage required to drive the Reference Oscillator off frequency in proportion to the engine speed deviation.

(b) The Phase Comparator Circuit receives signals from the Pickup Signal Amplifier and the

Reference Frequency Oscillator and compares the difference in frequency. The Phase Comparator measures the amount the engine signal is ahead or behind the Reference Oscillator signal. Its voltage output is used to force the Reference

Oscillator to the same frequency as the signal from the engine.

The Phase Comparator output is proportional to the speed error. The gain control is used to couple the Phase Comparator output to the Reference Oscillator.

By increasing the coupling, a small voltage change from the Phase Comparator represents a large frequency change and vice-versa.

It has an adjustable means to control the magnitude and time constant of the drop to match the dynamic characteristics of the engine. The output current switching portion of the circuit provides current to drive the actuator.

The output transistor is switched on and off at a frequency of 200 Hz.

This is above the natural frequency of the actuator. The actuator responds to the average current from the transistor and moves in proportion to position the engine throttle. The output transistor is switched on and off to reduce

power dissipation.

b. Malfunction.

The following procedures are to be performed with the Governor Control Unit in the generator set.

(1) Connect the breakout cable between

wiring harness plug P17 (1, figure 7-15) and the

electric governor.

(2) Using a digital voltmeter, make the

voltage readings in table 7-4 at the breakout

cable plug.

All readings are measured between the terminal and ground. Terminals F, G, H and T are ground.

Removal.

(1) Disconnect electrical connector P17

(1, figure 7-15).

(2) Remove 4 hex head screws (2), lock washers (3) and nuts (4).

(3) Remove the control unit.

Installation.

Install the Governor Control Unit in reverse order of removal procedures.

e. Adjustment Procedure.

(1) Disconnect the actuator linkage rod from the engine fuel shutoff lever.

(2) Place the generator set START-RUN-STOP switch (located on the generator set control panel in the RUN position.

(3) Place the generator set BATTLE SHORT

WITCH (located on the generator set control panel in the ON (override) position.

(4) Beginning at the fully counterclockwise position, rotate the engine fuel shutoff lever in a clockwise direction until a slight resistance is felt; hold the lever in this position.

NOTE

This resistance is the fuel injection pump’s internal governor linkage hook engaging the metering valve arm.

(5) Move the actuator 1 ever to the “full fuel” position.

This is the direction against the spring resistance (fully counterclockwise).

Change 9 7 - 1 9

7-20

Figure 7-14.

TERMINAL

NORMAL VALUE

Table 7-4.

Governor Malfunction Testing

PROBABLE

CAUSE OF NON-NORMAL READING CORRECTIVE ACTION

1.0 volt AC-RMS minimum while cranking.

Defective magnetic pickup.

Replace magnetic pickup.

Gap too large between magnetic 2. Readjust magnetic pickup.

pickup and gear teeth.

Improper or defective wiring 3. Replace wiring harness.

to the magnetic pickup.

10.1 + .20 volts DC while 1.

D.C. power not connected or 1. Connect D.C. power supply; energized (Internal regulow battery voltage.

replace D.C. battery.

lated D.C. supply).

Frequency trim potentiometer 2. Replace Control Unit.

shorted, grounded or miswired.

Wiring error.

Defective control unit.

Replace wiring harness.

Replace control unit.

Above 5.1 volts D.C. while 1.

Frequency adjust set too low. 1. Turn Frequency adjust screw running. (inverse speed clockwise.

error signal).

Defective control unit.

Replace control unit.

Above 5.1 volts is under speed signal. Below 5.1

volts is over speed signal.

On speed will indicate a steady 5.1 volts.

8.5 to 9.5 volts D.C. while 1. Battery voltage may be too cranking.

(Proportional low while cranking.

actuator voltage).

Defective Control Unit.

2.5 volts D.C. maximum while cranking. (Transister voltage).

Charge D.C. battery; replace

D.C. battery.

Replace Control Unit.

Output transistor open (defec- 1. Replace Control Unit.

tive Control Unit).

Defective Actuator.

Replace Actuator.

Error in wiring to Actuator. 3. Replace Wiring Harness.

(6) Measure the center to center distance between the hole in the fuel shutoff lever and the hole in the actuator lever. Adjust the rod ends on the threaded linkage rod so that the center to center distance of the rod ends is the same or slightly longer than that measured between the fuel shutoff lever and the actuator lever.

(The 3.75 dimension is only approximate. If the linkage is too short, the actuator lever will attain its “no fuel” position [full clockwise] before the fuel shutoff lever reaches its “no fuel” position; the fuel shutoff lever will never reach

“no fuel”.

If the linkage is too long, the actuator lever will reach its “full fuel” position

[full counterclockwise] before the fuel shutoff lever reaches its “full fuel” position; full load will not be reached.) It may be necessary to readjust the position of the fuel shutoff lever and/or the actuator lever to accommodate the center to center distance of the rod ends and to assure complete fuel shutoff and full load operation.

Fuel shutoff and actuator lever adjustments will be covered under replacement procedures.

Tighten the nuts on the linkage rod against the rod ends to maintain proper spacing.

(7) Return the generator set START-RUN-STOP switch to the STOP position and the BATTLE SHORT switch to the OFF position.

(8) Reconnect the actuator linkage rod end to the engine fuel shutoff lever.

(9) Adjust the control unit gain control to its approximate mid-range position.

(10) Adjust the control unit stability control to its fully counterclockwise position.

(11) Adjust the generator set frequency adjust potentiometer (pot) (located on the generator set control panel) to mid-range.

(12) Using a small screwdriver, turn the control unit frequency adjust screw (located on the left side vertical face of the control unit) at least 22 turns counterclockwise (opposite increase arrow).

This will give the lowest possible engine governed speed.

NOTE

Two people will be rewired to adjust the control unit.

Ensure that the actuator linkage rod and all levers are securely fastened and move freely (without binding) before operating the engine. Manually overcome the actuator until adjustment of the control unit is completed and the governor is in control. Adjustment of the control unit will be made with the engine operating in a no-load condition.

(13) Start the engine, manually operating the fuel shutoff lever.

Change 9

7-21

(14) Turn the control unit frequency adjust screw clockwise until the proper engine speed is obtained.

Several turns may be required. The generator set frequency adjust pot should now have sufficient adjustment travel to cause the generator set frequency meter to indicate beyond both of its extreme limits (388-412

Hz).

(15) If the engine is unstable as indicated by continuous movement of the actuator lever, turn the control unit gain control counterclockwise until stability is obtained as indicated by a stationary actuator lever. Readjust the control unit frequency adjust screw to the proper engine speed.

(16) Turn the control unit gain control clockwise until the engine becomes just unstable; back the gain control counterclockwise until the engine is again stable.

(17) Turn the control unit stability control clockwise until the engine becomes just unstable; back the stability control counterclockwise until the engine is again stable.

NOTE

The governor is now set to a nominally good operating point.

(18) Adjust control unit gain, stability and frequency under various load conditions and load changes to obtain the desired governing characteristics.

(19) When the electric governor system is properly adjusted, the locknuts on the control unit gain and stability controls should be tightened.

7-11. ACTUATOR UNIT.

a. Removal.

(1) Disconnect electrical connector P22, (1, figure

7-16).

(2) Disconnect the actuator lever from the actuator linkage rod by removing the hex head cap screw (2), flatwasher (3), and the self-locking nut (4).

NOTE

It may be necessary to remove the actuator bracket to gain access to the hardware securing the actuator to the actuator bracket. If this is not necessary, proceed to paragraph (3). If removal is required, then proceed as follows:

(a) Loosen the drive belt of the engine alternator.

(b) Remove the two hex head screws (5) and lock washers (6) securing the actuator bracket, through spacers (7), to the engine through the alternator mounting bracket.

(3) Disconnect the actuator from the actuator bracket by removing two hex head screws (8), flatwashers (9), lock washers (10) and nuts (11).

Remove the actuator.

b. Testing.

(1) Using an ohmmeter, check for continuity between pins A and B and pins C and D. Replace actuator if there is no continuity.

(2) Check for short circuit between each pin on the connector and the housing. Replace actuator if any pin is shorted to case, c. Installation.

(1) Position the actuator lever (12, figure 4-30.3) roughly horizontal by loosening the nut on the splined shaft end of the actuator lever, rotating the lever and tightening the nut.

(2) Align the actuator with the two holes in the actuator bracket, secure the actuator to the actuator bracket with two ¾-inch long hex head screws (8), flatwashers (9), lock washers (10) and nuts (11).

NOTE

If the actuator bracket has not been removed, proceed with paragraph (3). If the bracket must be installed, proceed as follows:

(a) Insert the spacers (7) through the alternator mounting bracket.

(b) Secure the actuator bracket to the engine by inserting the two 1½-inch long hex head screws (5), lockwashers (6), into the appropriate holes in the actuator bracket, through the spacers (7) and into the threaded holes in the engine; tighten the two screws.

(3) Attach the actuator lever to the actuator linkage rod with the 1½-inch long hex head cap screw (2), two flatwashers (3) and the self-locking nut (4).

(4) Connect electrical connector P22 (l).

7-12. ELECTRIC GOVERNOR MAGNETIC PICKUP.

a. Removal.

(1) Disconnect electrical connector P23 (1, figure

7-17).

(2) Loosen locknut (2) and unscrew the threaded magnetic pickup from the flywheel housing (3). Remove the magnetic pickup.

b. Testing.

(1) Using an ohmmeter, test for continuity between pins A and B on the connector.

(2) If the circuit is open discard the magnetic pickup.

c. Installation.

(1) Rotate the engine until the top land of one gear tooth is in line with the center of the threaded hole in the flywheel housing.

(2) Replace the magnetic pickup (3) into the threaded hole in the flywheel housing until the tip contacts the top of the gear tooth. Back the magnetic pickup out onehalf to three-quarter turn and secure with the locknut (5) provided.

(3) Connect electrical connector P23 (1),

7-22 Change 10

Figure 7-15.

Governor Control Unit Removal and Installation

Change 9

7 - 2 3

7-24

Figure 7-16.

Figure 7-17.

7-25

7-26 Change 9

Figure 7-18.

400 Hz Electric Governor System Wiring

Harness Assembly Drawfing No. 84-704

(Sheet 1 of 2)

CHAPTER 8

RELAY TABLE GROUP REPAIR INSTRUCTIONS

8-1. Scope.

a . Section I of this chapter includes a brief description of the assemblies that make up the relay table group, overall functional operation, symptoms of relay table group malfunction, and relay table group equipment tests.

b . Subsequent sections of this chapter include repair instructions for the assemblies which are part of the relay table group.

8-2. Relay Table Group Description.

a. The relay table and related parts (fig. 8-1)

intrudes the control relay assemblies, the excitation assembly exciter and the load measuring unit. The load measuring unit, and the excitation assembly exciter are common to all modes and classes of sets.

Control relay assemblies include the tactical relay assembly (used on all sets), precise relay assembly

(used on Mode 1, Class 1 sets), and two different special relay box assemblies (one used on Mode I sets and the other used on Mode II sets).

b. The tactical, precise, and special relay box assemblies contain control relay modules for overvoltage, short circuit, and reverse power on all sets. Class 1 sets also contain additional control

Section I. INTRODUCTION

relay modules for underfrequency, undervoltage, and permissive paralleling.

c. The excitation assembly exciter system provides control of excitation voltage to the main generator to produce voltage buildup in the generator field coils.

The excitation system assembly contains a voltage regulator that senses the generator output voltage and uses it as a reference to control field current in the generator and thus regulate the generator output voltage level.

d. The load measuring unit (LMU) is supplied on all sets. The LMU provides a dc signal proportional to the real power (kw) being delivered by the main

generator. Refer to paragraphs 7-1 and 7-2.

8-3. Relay Table Group Symptoms and Isolation of

Malfunction.

Malfunctions in the relay table group will be electrical in nature, and will affect the generator output voltage, via the excitation system assembly, and normal systern operation due to a malfunctioning protection relay in the tactical precise or set special relay box assembly. If the set is in operable condition, the equip-

ment tests listed in table 8-1 can be performed to iso-

late the malfunction.

Section II. CONTROL RELAY ASSEMBLIES

8-4. Scope

This section includes repair instructions for the tactical relay assembly, precise relay assembly, and special relay box assemblies.

(a) Remove screws (1) and washers (1A) and remove cover (2).

(b) Tag and disconnect all wiring harness

8-5. Removal.

leads.

See figure 8-1, unscrew electrical connectors, and

remove the tactical relay assembly (2), precise relay assembly (4), special relay assembly (14), excitation assembly (18), and relay table (52), as required.

8-6. Disassembly.

NOTE

Tag all electrical connections removed during disassembly for position identification during reassembly.

a . Tactical Relay Box Assembly.

(1) See figure 8-2 and disassemble the tactical

relay assembly as follows:

with figure 8-2.

(2) See figure 8-3 and disassemble the tactical

relay resistor assembly.

(1) On Class 1, Mode 1 Sets, see figure 8-4 to

disassemble the precise relay box assembly.

NOTE

Tag and disconnect all electrical leads prior to removal of wiring harness (7).

(2) See figure 8-5 for disassembly of the re-

sistor assembly.

Change 7 8-1

Table 8-1.

Relay Table Group Equipment Tests

Malfunction

1. Main generator output too low, too high, or failure to flash.

2. Generator runs at less than 130 percent of rated current for 10 minutes; CB2 drops out and overload indicater lights.

3. Generator runs at normal voltage, set shuts down and overvoltage indicator lights.

4. Generator runs at rated voltage,

CB2 drops out and undervoltage indicator lights.

5. Generator runs at rated load, CB2 drops out, and short circuit indicator lights.

6. Generator runs at rated load, CB2 drops out, and reverse power indicator lights.

7. Generator runs at rated load, CB2 drops out with no malfunction indicated.

B. Generator runs at rated frequency,

CB2 drops out, and underfrequency indicator lights.

Separately excite field with dc power supply.

Place battle short switch in on position.

On equipment test a. Output normal.

b. Output low, high, or will not flash.

a. Overload indicator lights and

CB2 remains close.

b. Unit operates normally.

Place battle short switch in on position; overvoltage indicator lights but the set does not shut down.

Place battle short switch in on position; undervoltage indicator lights and CB2 remains close.

None required.

Place battle short switch in on position; reverse power indicater lights and CB2 remains close.

Place battle short switch in on position; unit operates nor mally.

Place battle short switch in on position; underfrequency indicater lights and CB2 remains close

Malfunctioning assembly a. Excitation system assembly.

b. Generator assembly.

a. Overload relay.

b. See table 2-2.

Overvoltage relay.

Undervoltage relay.

Short circuit relay.

Reverse power relay.

Permissive parallel relay.

Under frequency relay.

Location a. Relay table group.

b. Generator assembly.

a. Tactical relay

b. See table 2-2.

Tactical relay box.

Mode I - Precise relay box.

Mode 11- Special relay box.

Tactical relay box.

box.

Mode I - Precise relay box.

Mode XI - Special relay box.

Mode I - Precise relay box.

Mode II- Special relay box.

Mode I - Precise relay box.

Mode II - Special relay box.

8-2

Table 8-1. Relay Table Group Equipment Tests (Cont)

On equipment test

Malfunctioning assembly

Malfunction

9 . Paralleling lamps do not illuminate when the singleparallel switch is placed to the parallel position when attempting to parallel two generators.

10. Engine generator set cranks, but will not start.

Check resistance between connections

19 and 20, 7 and 8 of A5, dc relay assembly.

Resistance should be

7500 ± 5 percent ohms. An infinite resistance indicates a malfunction.

1. Engine-generator set will not start.

Check resistance between A5 connections 21 and 24 with the positive lead or connection 21. The value indicated will be approximately 500 ohms. Reverse the leads, the resistance shall be infinite. An infinite resistance in both directions indicates a malfunction.

Check resistance between A5 connections 11 and 10 with the positive lead on connection 11. The value indicated will be approximately 500 ohms. Reverse the leads, the resistance shall be infinite. An infinite resistance in both directions indicates a malfunction.

Dc relay assembly.

Location

Special relay box.

Key to Figure 8-1

1. Screw

1A. Screw

1B. Washer

2. Tactical relay box assy

3. Screw

4. Precise relay box assy

Mode I. Class 1 sets only

5. Screw

6. Nut

7. Load measuring unit

8. Screw

9. (Deleted)

10.

Screw

11.

(Deleted)

12.

Terminal lug

12A. Clamp

13.

Wrench

14.

Special relay box assy

15.

Screw

16.

Nut

17.

Clamp

18.

Excitation assy

1 9 .

20.

21.

22.

31.

32.

33.

34.

35.

36.

23.

24.

25.

26.

27.

28.

29.

30.

37.

38.

39.

Clamp

Screw

Chain

Nut

Screw

Clamp

Nut

Screw

Clamp

Nut

Clamp

Screw

Bracket

Screw

Nut

(Deleted)

Clamp

Screw

Nut

Bracket

Screw

40. Nut

41. Clamp

42. Screw

43. Nut

44. Clamp

45. Screw

46. Nut

47. Clamp

48. Grommet

49. Screw

49A. Washer

50. Nut

51. Washer

52. Table

53. Screw

54. Nut

55. Support bracket

56. Screw

57. Nut

Change 7 8-3

8 - 4 C h a n g e 7

Figure 8-1.

Relay Table and Related Parts

ME 6115-545-34/8-1 C7

1. Screw

1A. Washer

2. Cover

3. Screw

4. Nut

5. Screw

6. Nut

7. Wiring harness

8. Jumper

9. Screw

10. Terminal board

11. Screw

12. Nut

13. Resistor assy

14. Screw

15. Over voltage relay module

16. Screw

17. Short circuit relay module

18. Screw

19. Reverse power relay module

20. Screw

Figure 8-2. Tactical Relay Box Assembly

21. Overload relay module

22. Screw

23. Nut

24. Chassis

ME 6115 -545-34/8-2 C7

C h a n g e 7 8 - 5

8-6

Figure 8-3. Tactical Relay Resistor Assembly

ME 6115-545-34/8-3

1. Screw

2. Cover

3. Screw

4. Cover

5. Screw

6. Nut

7. Wiring harness

8. Switch

8A. Washer

9. Rheostat

10. Rivet

11. Plate

12. Rivet

13. Plate

14. Jumper

15. Screw

16. Nut

17.

18.

19.

20.

21.

22.

23.

Terminal board

Screw

Nut

Resistor assy

Screw

Under frequency relay module

Screw

Figure 8-4. Precise Relay Box Assembly

24. Permissive parallel relay module

25. Screw

26. Under voltage relay module

27. Chassis

ME 6115-545-34/8-4 Cl

Change l 8-7

8-8 Change 1

Figure 8-5. Resistor Assembly (A6)

(1) See figure 8-6 and disassemble the special

relay box assembly as follows:

(a) Remove screws (1) which secure cover

(44) to housing (79).

(b) Remove screws (1) which secure panel

(2) to housing (79).

24, 26, arid 28) and nuts (12, 15, 17, 19, 21, 23, 25,

27, and 29) which secure wiring harness connectors to, cover (44) and housing (79), and remove gaskets (31,

32, 33, 34, 35 and 37) and cover (44).

(d) Remove attaching hardware from all components within the special relay box and remove wiring harness (30) with components connected.

(e) Tag and disconnect wiring harness leads from components.

(2) See figure 8-5 to disassemble the resistor

assembly of the special relay box assembly (Mode II

Sets only).

(3) See figure 8-7 to disassemble the dc relay

assembly of the special relay box assembly.

8-7. Inspection and Testing.

a. Tactical Relay Box Assembly.

(1) Inspect all components for signs of physical damage.

(2) Test the short circuit relay as follows:

(a) Connect a light and a 24 Vdc power supply in series with terminals 5 and 6 (DS1), also with terminals 7 and 8 (DS2). Relay trip will be indicated by the two lights.

DS1 shall extinguish; DS2 shall light.

See figure 8-8 for test setup.

(b) Connect a variable (0 to 120 volts) ac voltage source (50 to 400 Hz) between terminals 1 and

4 and slowly increase the voltage. The relay shall transfer lights when voltage equals 24 volts - 1 volt.

Repeat the test with the input connected to 2 and 4, and then again, between 3 and 4 by moving switch S2. The trip points should be within 1 volt of each other.

2, 3, 4 shall be electrically isolated with the relay in either position.

(3) Test the overvoltage relay as follows.

(a) Connect a variable (0 to 160 volts) ac voltage source and variable frequency (50 to 450 Hz)

source to terminals 1 and 2. (See fig. 8-9. )

(b) Connect a lamp and 24 Vdc power supply in series with terminals 3 and 4 (DS1), also with terminals 7 and 8 (DS2).

1 and 2 and vary the frequency from 50 to 450 Hz.

DS1 should stay lit and DS2 shall remain extinguished.

(d) Slowly increase the voltage to 149 volts.

Vary the frequency from 350 to 450 Hz. DS1 should stay lit and DS2 shall remain extinguished.

Vary the frequency from 50 to 100 Hz. DS1 should stay lit and DS2 shall remain extinguished.

(f) Set the frequency at 50 Hz and increase the voltage to 156 volts.

DS1 shall extinguish and

DS2 shall light.

Repeat for the frequency at 60, 70 and 100 Hz. After each trip, remove ac power to clear the relay.

(g) Set the frequency at 350 Hz and increase the voltage to 151 volts.

DS1 shall extinguish and DS2 shall light.

Repeat for the frequency 400 to 450 Hz.

After each trip, remove ac power to clear the relay.

(h) Terminals 3, 4, 5, and 6, 7, 8 and terminals–l and 2 shall be electrically isolated.

8-10.

(4) Test the reverse power relay as follows:

(a) Connect relay as illustrated in figure

(b) With all switches open, energize 5 Vdc variable power supply and adjust until V1 reads 3 volts .

Vdc supply and close switches S4, S1, and S5. Lamp

DS2 should light and DS1 should be extinguished.

(d) Energize 0 to 10 Vac power supply and adjust voltage until V2 indicates 5 volts. Adjust O to

5 Vdc supply to a value less than 1 Vdc shown on V1.

Position switch S2 to A and close switch S3. Raise voltage of 0 to 5 Vdc power supply until DS2 extinguishes and DS1 lights.

DS1 should light when V1 indicates 1 to 3 volts.

(5) Test the overload relay as follows:

(a) Connect the relay in the test setup shown

in figure 8-11.

(b) With the 120/208 Vac power source energized, turn on the 24 Vdc power supply and close switch

S1. Lamp DS1 should light and DS2 should be extinguished.

DS1 and DS2 should not change states.

(d) Adjust autotransformer T1 until ammeter

Al indicates O. 975 ampere. After ± 2 minutes, DS1 and DS2 should transfer states.

Change 1 8-9

Key to fig. 8-6.

Screw

Panel

Screw

Nut

*5.

Connector assy

*6.

Connector

*6A. Screw

*7.

Chain

Screw

Nut

10.

Dust cap

11.

Screw

12.

Nut

13.

Dust cap

14.

Screw

15.

Nut

16.

Screw

17.

Nut

18.

Screw

19.

Nut

20.

Screw

21•

Nut

22.

Screw

23.

Nut

24.

Screw

25.

Nut

26.

Screw

27.

Nut

28.

Screw

29.

Nut

30.

Wiring harness

31.

Gasket

32.

Gasket

33.

Gasket

34.

Gasket

35.

Gasket

36.

Gasket

37.

Gasket

38.

Screw

39.

Nut

72.

**73.

74.

**75.

76.

77.

**78.

79.

59.

60.

61.

62.

63.

64.

65.

66.

67.

68.

69.

70.

**71.

54.

55.

56.

57.

58.

48.

49.

50.

51.

52.

53.

40.

41.

42.

43.

44.

**45*

**46.

**47.

Washer

Nut

Washer

Cover

Rheostat (R28)

Rivet

Plate

Rheostat (R29)

Rivet

Plate

Nut

Screw

Transformer

Screw

Nut

Resistor

Bracket

Nut

Dc relay assy

Jumper

Screw

Terminal board

Screw

Terminal board

Screw

Shunt

Nut

Screw

Relay

Nut

Relay Permissive Parallel

(K16)

Screw

Relay Underfrequency (Kl2)

Screw

Relay Under voltage (Kl1)

Nut

Screw

Resistor assy (A6)

Housing

- Mode I sets

** - Mode II sets

8-10 Change 1

Figure 8-6.

Special Relay Box Assembly (Sheet 1 of 2)

ME 6115-545-34/8-6(1) Cl

Change l 8-11

8-12 Change 7

Figure 8-6. Special Relay Box Assembly (Sheet 2 of 2)

Figure 8-7. DC Relay Assembly (A5)

ME 6115-545-34/8-7 Cl

Change 1 8-13

ME 6115-545-34/8-8 Cl

Figure 8-8. Short

Circuit Relay Test Set-up

(e) Repeat paragraph (d) for autotransformers T-2 and T3. The test results should be the same as for T1. Repeat paragraph (d) for all

3 autotransformers.

The test results should be the same.

(6) Make a point-to-point check of all wiring and chassis -mounted components. (See schematic

diagrams in Chapter 1.)

8-14 Change 1 b. Precise Relay Box Assembly (Mode I, Class

1 Sets).

(1) Inspect all components for signs of physical damage.

(2) To test the underfrequency relay, see

figure 8-12 and test as follows:

Figure 8-9. Overvoltage Relay Test Set-Up

ME 6115-545-34/8-9 C1

Change l 8-15

8-16 Change 1

Figure 8-10.

Reverse Power Relay Test Set-Up

ME 6115-545-34/8-10 Cl

REF DES

DS1 , DS2

R1, R2, R3

Tl, T2, T3

DESCRIPTION

INDICATOR LIGHT

RESISTOR, FIXED

SWITCH, DC POWER

3 PHASE VARIAC

ME 6115-545-34/8-11 C1

(a) Connect an external switch across terminals and 8. Close switch.

(b) Adjust the frequency to 50 Hz and the input voltage to 120 volts. Relay contacts should pick up; lamp DSl should light and DS2 should extinguish.

(d) Raise frequency slowly until contacts pick up (DS1 should light and DS2 should extinguish).

Contacts should pick up at 45 to 49 Hz.

(e) Raise voltage to 132 volts and check for drop out lights transfer). Drop out should occur within + 1 Hz of drop out at 120 volts.

(f) Lower voltage to 108 volts. Drop out

(lights transfer) should occur within ± 1 Hz of drop out at 120 volts.

Figure 8-11. Overload

Relay Test Set-Up

(g) Open switch between terminals 7 and 8, and adjust input frequency to 60 Hz. Repeat steps

(b) through (f). Drop out should occur at 55 ± 1 Hz; pick up at 58 + 1 Hz.

(3) To test the undervoltage relay, see figure

8-13 and refer to paragraph 8-7c (4), but adjust

frequency for 50/60 Hz operation.

(4) To test the permissive parallel relay,

perform the procedure in paragraph 8-7c (6), but

adjust frequency for 50/60 Hz operation.

(4a) To test the resistor assembly (A6), refer

to figure 1-7 and proceed as follows:

(a) Check the resistance of R4 between points 1 and 2 on terminal board TB1 06. Resistance should be 250 ohms.

(b) Check the resistance of R5 between points 3 and 4 on terminal board TB106. Resistance should be 250 ohms.

Change 1 8-17

REF DES

DS1, DS2

DESCRIPTION

INDICATOR LIGHT

FREQUENCY METER, 0-400 Hz

SWITCH

6 on terminal board TB106. Capacitance should be 60 uf.

(d) Replace components found to be defective.

(4b) Test the total resistance of rheostat (R28).

Total resistance should be 15,000 ohms + 10%. Test resistance between wiper arm and either–end of rheostat. Resistance should vary between 0 and

15,000 Ohms.

(5) Make a point-to-point check of all wiring and chassis mounted components.

c. Special Relay Assembly.

(1) Check all components for signs of physical damage.

(2) To test the crank relay (K3), apply 24-28

Vdc across the two small terminals and check for continuity across the two large terminals.

(3) See figure 8-12 and connect the under-

frequency relay (Kl2) (Mode II Sets) as shown.

Test as follows:

ME 6115-545-34/8-12 C1

Figure 8-12. Underfrequency Relay Test Set-Up

(a) Adjust the frequency to 400 Hz and the input votage to 120 volts. Relay contacts should

“pick up”; lamp DSl should light and DS2 should extinguish.

(b) Lower frequency slowly until relay contacts drop-out (lights transfer). Contacts should drop out at 370 + 5 Hz.

Contacts should pick up at 370 to 395 Hz.

(d) Raise voltage to 132 volts and check drop out (lights transfer). Drop out should occur within ± 1 cycle of drop out at 120 volts.

(4) To test the undervoltage relay (Kll),

(Mode XI) connect the relay in a test circuit as illus-

trated in figure 8-13, and proceed as follows:

(a) Adjust ac power supply to 120 volts,

400 Hz. Lamp DSl should extinguish and DS 2 should light.

(b) Reduce voltage slowly to 104 volts and hold for 2 minutes. Lamp DS1 and DS2 shall maintain states.

8-18 Change 1

ME 6115-545-34/8-13 Cl

Figure 8-13.

Undervoltage Relay Test Set-Up

DSl and DS2 shall transfer states within 4 to 8 seconds.

aneouss.

(d) Increase voltage slowly to l13 volts.

Lamps DSl and DS2 shall transfer states.

(e) In one step, lower voltage to 48 volts.

Transfer of states of DSl and DS2 shall be instant-

(f) Reduce frequency to 50 Hz and repeat same results.

(5) T

O test the DC relay assembly (A5), connect the dc relay assembly in a test circuit as

illustrated in figure 8-13A and proceed as follows:

(a) Connect 120 VAC, 400 hertz supply across terminals 18 and 22 of dc relay assembly and close Sl switch. Measure resistance between terminals 7 and 8 and 19 and 20. Measured resistance should be 2500 ohms for both measurements. If this reading is not obtained check for defective resistors

R3, R7, R8, defective rectifier CR4 or defective relay K7.

(b) Remove power from assembly and measure resistance between terminals 19 and 20, and 7 and 8 of dc relay assembly. Resistance should be 7500 ohms for both measurements. If this reading is not obtained check for defective relay K7.

(c) Check continuity. between terminals 11 and 10 and 21 and 23. (Ohmmeter + lead placed on terminals 11 and 21). There should be continuity.

If there is no continuity check for defective diode

CR3 or CR6.

Change 1 8-18A

Figure 8-13A. DC Relay Assembly (A5) Test Setup

(d) Connect 24 vdc across terminal 6 (+) and 15 (—) and close S2 switch. There shouldn‘t be continuity between terminals 4 and 16, and there should be continuity between terminals 5 and 17. If this is not obtained, check for defective relay K8.

(6) T

O test the permissive parallel relay (K16) (Mode

11 Sets), see figure 8-14 and test as follows:

(–).

(a) Apply 24 vdc to terminals 3 (+) and 4

(e) Remove 24 vdc from terminals 6 and 15 and connect across terminals 13 and 15 and close S3 switch. Measured voltage between terminals 3 and 15 should be 24 vdc; zero between terminals 3 and 13. Continuity should exist between terminals 1 and 14 and 2 and 15. If these readings are not obtained, check for defective relay K5.

(b) Apply 20 volts, 400 Hz across terminals

1 and 2.

8-18B Change 10

(d) Slowly decrease the voltage at terminals

1 and 2. The relay must reset when the voltage is

8 ± vo1t ac.

(7) To test the current transformer, proceed as follows:

(a) Connect an ohmmeter across terminals

1 and 2, and across 3 and 4. In each case, the resistance must be 0.34 ohms ± 10 percent.

(b) Apply 15 Vac to terminals 1 and 2 with secondary open circuit. The existing current must be less than 0.24 ampere.

The voltage across terminals 3 and 4 must be 15 volts ac ± 1 percent.

(7a) Test the total resistance of rheostat

(R28), (Mode II). Total resistance should be

15,000 ohms ± 10%. Test resistance between wiper arm and either end of rheostat. Resistance should vary between 0 and 15,000 ohms.

(7b) Test the total resistance of rheostat

(R29). Total resistance should be 12 ohms. Test resistance between wiper arm and either end of rheostat. Resistance should vary between 0 and

12 ohms.

(7c) To test resistor assembly (A6) (Mode II) refer to paragraph (4a) and proceed as instructed.

(7d) Check resistance of resistor (R31). Resistance should be 10 ohms.

Change 1 8-19

ME 6115-545-34/8-14 C1

Figure 8-14. Permissive Parallel Relay Test Set-Up

(7e) To test shunt (R13), apply 20 amperes to input of shunt and measure output with a millivoltmeter. Output should be 50 millivolts.

(8) Make a point-to-point check of all wiring and chassis mounted components. (See schematic

diagrams in Chapter 1.)

8-8. Repair, Reassembly, and Installation.

a. Repair.

(1) Replace during testing.

any relay found to be defective

(2) Replace and transformers.

all defective diodes, resistors,

8-20 Change 1

(3) If any connections are opened or bared for test purposes, or if any defective components are replaced the effected area and component must be coated with polyurethane resin to prevent oxidation or other corrosion. The coating must be of a minimum thickness of 0.007 inches and air bubble entry into the applied polyurethane must be controlled so that the legibility of component coding and identification is not impaired.

(4) Replace defective connectors.

(5) Repair or rebuild wiring harnesses as

required. See wiring schematics in Chapter 1 and

wiring harness diagrams in Chapter 5.

b . Reassembly.

(1) See figure 8-6 and 8-7 and paragraph 8-69

and reassemble the special relay box assemblies in reverse order of disassembly. The dc relay assembly will be coated in accordance with the requirements of

paragraph 3-3c(5).

(2) See figures 8-4 and 8-5 to reassemble the

precise relay assembly.

(3) See figures 8-2 and 8-3 to reassemble the

tactical relay assembly. Rewire relay resistor

assembly as shown in figure 8-3.

c . Installation.

(1) See figure 8-1 and install special relay

box, precise, and tactical relay assemblies on the relay table.

(2) See figure 8-1 and install relay table.

8-10. Removal.

exciter (18) as follows: to relay table (52).

8-11. Disassembly.

NOTE

Tag all electrical leads removed during disassembly for positive identification during reassembly.

a. Excitation Assembly Exciter. To disassemble

excitation assembly exciter. See figure 8-15 and

proceed as follows: to chassis (3) and remove cover.

(2) connector

(8).

(3)

(4)

5 )

Remove screws (4) which secure harness to chassis (3).

Unscrew connector from voltage regulator

Remove screw (9) and clamp (10).

remove wiring harness (6).

Section III. EXCITATION SYSTEM ASSEMBLY

Key to fig. 8-15.

8-9. Scope.

This section contains repair and adjustment instructions for the excitation assembly exciter.

See figure 8-1 and remove the excitation assembly

b. Remove screws (19) which secure exciter (18)

(1) Remove screws (1) which secure cover (2)

Tag and disconnect all electrical leads and

(6) Remove semiconductors (11, 12 and 13).

(7) Remove heatsinks (18, 19, and 24) by removing associated hardware (14 thru 17 and 20 thru 23) and remove insulators (25 and 26).

(8) Remove resistors (29, 30 and 31) by removing screws (27) and washers (28).

1. Screw

1A. Washer

2. Cover

3. Chassis

3A. Screw

4. Screw

5. Nut

6. Wire harness assy

7. Screw

8. Voltage regulator (A10)

9. Screw

10. Clamp

11. Semiconductor

12. Semiconductor

13. Semiconductor

14. Screw

15. Nut

16. Screw

17. Washer

18. Heats ink

19. Heatsink

2 0

S c r e w

21. Nut

22. Screw

23. Washer

24. Heatsink

25. Insulator

26. Insulator

27. Screw

28. Washer

29. Resistor

30. Resistor

31. Resistor

32. Screw

33. Bracket

34. Bracket

35. Screw

36. Terminal block

37. Screw

38. Transformer

39. Screw

40. Electronic component assy

41. Spacer

42. Bracket

43. Screw

44. Screw

45. Filter

Change 7 8-21

8-22 Change 7

Figure 8-15. Excitation System Assembly

ME 6115-545-34/8-15

(9) Remove screws (32) which secure brackets

(33 and 34) to chassis (3) and remove brackets.

(10) Remove screws (35) which secure terminal board (36) to chassis (3) and remove terminal board.

(11) Remove screws (37) which secure transformer (38) to chassis (3) and remove transformer.

(12) Remove screws (39) which secure electronic component assembly (40) to bracket (42) and remove electronic component assembly and spacers (41).

(13) Remove screws (43) which secure brackets

(42) to chassis (3) and remove brackets.

(14) Remove screws (44) which secure filter

(45) to chassis (3) and remove filter.

b. Voltage Regulator. See figure 8-16 to disas-

semble the voltage regulator.

c. Voltage Regulator Printed Circuit Board Assem-

bly: See figure 8-17 to disassemble the voltage regu-

lator printed circuit board assembly.

d. Electronic Component Assembly. See figure

8-13 to disassemble the electronic component

assembly.

8-12. Inspection and Testing, a.. Inspection.

Proceed as follows:

(1) Inspect the complete assembly and all components for signs of physical damage.

(2) Inspect electrical components for signs of overheating.

b. Testing. See figure 1-8 and proceed as follows:

(1) Disconnect diodes CR201 through CR206

from heat sinks and test each diodes per paragraph

14-10.

(2) Refer to table 8-2. Disconnect one side of

each resistor, and use ohmmeter to check resistance.

(3) Check A201 RFI filter by disconnecting filter leads and checking resistance across terminals

1 and 1A, and across terminals 2 and 2A. Resistance should be less than two ohms.

(4) Check SCR (Q205) as follows:

(a) Disconnect lead from terminal 1 of voltage regulator circuit card assembly.

(b) Set ohmmeter to RI scale. Connect meter positive lead to stud of SCR and negative lead to large terminal of SCR. Ohmmeter should indicate open circuit. Reverse leads.

(5) Check voltage regulator and electronic component circuit board assemblies as follows:

(a) Interconnect excitation system assembly

to test setup as shown in figure 8-19.

(b) Adjust variac for 70 volt ac input indication on ac voltmeter. Dc voltmeter should read approximately 25 volts.

(d) Increase ac input gradually. At approximately 95 volts input, dc voltmeter should drop to zero (indicating zero field voltage output). If dc voltage does not drop to zero, replace both the electronic component and voltage regulator circuit boards and repeat steps (a), (b), (c), and (d).

(6) See figure 1-8 and check the 50/60 Hz

electronic component assembly as follows:

(a) Connect one end of a 1000 ohm 1/2 watt carbon resistor to terminal 4.

Table 8-2. Excitation Assembly Resistor Values

Reference Mode I Sets

Mode 11 Sets

Designation (50/60 Hz) (ohms) (400 Hz) (ohms)

R201

R202

R203

R204

R205

R206

R207

R208

R209

R210

R211

R212

R213

R214

220

2000

100

3300

680

100

1000

2700

50000

10000

3000

5000

220

2000

100

3300

680

100

1000

2700

50000

10000

3000

5000

Reference Mode I Sets

Mode II Sets

Designation

(50/60 Hz) (ohms) (400 Hz) (ohms)

R215

R216

R217

R218

R219

R220

R221

R222

R223

R224

R225

R226

R227

150

1000

5100

5000

0.5

300

100

120

150

1000

5100

6.8

5000

0.5

300

100

120

Change 6

8-23

8-24 Change 1

Figure 8-16. Voltage Regulator

ME 6115-545-34/8-16 Cl

10.

1. Transistor

Transistor

Semiconductor

Resistor

Capacitor

Resistor

11.

12.

13.

14.

15.

16.

Resistor

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

Resistor

Transistor

Resist or

Transformer

Resistor

(Deleted)

Transipad

Screw

Washer

Nut

Terminal board

Printed circuit board

ME 6115-545-34/8-17 C7

Figure 8-17. Voltage Regulator Printed Circuit Board Assembly

Change 7 8-25

Screw

Nut

Washer

Terminal block

Semiconductor

Resistor

Semiconductor

10.

11.

Capacitor

12.

Clip

13.

14.

15.

Transistor

Pad

Eyelet

Capacitor

Resistor

16.

17.

18.

Resistor

Capacitor

18A. Capacitor

18B. Clip

18C. Eyelet

19.

Printed circuit board

ME 6115-545-34/8-18 Cl

Figure 8-18.

Electronic Component Assembly

(b) Connect the positive output terminal (4) of a variable 24 Vdc power supply to the other end of the resistor. Connect the negative (-) terminal of the power supply to terminal 3.

10 volts.

(d) Adjust the dc power supply voltage to

8-26 Change 1

(e) Slowly raise the ac power supply to

37 volts rms.

The dc voltage at terminals 3 and 4 shall drop sharply to below 1 volt.

(f) For the 400 Hz electronic component assembly, repeat steps (a) thru (e) using a 400 Hz v a r i a b l e a c p o w e r s u p p l y .

ME 6115-545-34/8-19

8-13.

Figure 8-19.

Excitation Assembly System Test Set-Up

Repair. Reassembly and Installation.

Repair.

(1) Relay circuit board assemblies found to be defective during testing.

(2) Replace all defective diodes, resistors, and transformers.

(3) Replace defective connectors.

(4) Repair or rebuilt wiring harnesses as re-

quired. See wiring schematics in Chapter 1 and

wiring harness diagrams in Chapter 5.

b . Reassembly.

(1) See figure 8-18 to reassemble the electronic

component assembly.

(2) See figure 8-16 and 8-17 to reassemble the

voltage regulator assembly.

(3) See figure 8-15 and refer to paragraph 8-11,

and reassemble the excitation system assembly in reverse order of disassembly, c.

Installation.

See figure 8-1 and refer to para-

gragh 8-10 to install the excitation system assembly.

8-14. Adjustments.

After the excitation system assembly is reinstalled, perform the following operational adjustments:

(1) With Voltage Adjust control on generator control panel set at approximately midpoint, start generator set.

8-27

TM 5-6115-545-34

(2) Adjust Set Point (R212) control to obtain rated voltage at generator output terminals.

(2) Perform checks in accordance with paragraph 16-11.

e. Equipment Test. If the excitation assembly has been

replaced, repaired or adjusted refer to Chapter 16, Section II and

conduct the following tests.

c. Gain. Adjust R211 for 14K ohms nominal.

(1) Regulation range test. Refer to paragraph 16-14.

d. Parallel Adjustment Procedures - Reactive Load

Sharing.

(1) Connect an external load bank capable of loading the generator set to full load at 0.8 power factor.

(2) Frequency and voltage regulation, stability and transient

response test, short term. Refer to paragraph 16-15.

8-15. Scope.

This section contains repair instructions for the load measuring unit.

8-16. Removal.

See figure 8-1 and remove the load measuring unit (7) as

follows:

Section IV. LOAD MEASURING UNIT b. With 120 volts on M3, no load on load bank (Rd), and 0 volts indicated on voltmeter (M1), voltmeter (M2) shall in-

dicate 0 to 0.4 Vdc. Resistor RI (17, fig. 8-20), internal to

load measuring unit, may be adjusted to obtain this reading.

c. With load on Rd, and 5.6 volts ac indicated on Ml, voltmeter M2 shall indicate 9.4 to 9.8 Vdc.

a. Unscrew electrical connector.

b. Remove screws (5) which secure load measuring unit

(7) bottom of relay table (52).

8-17. Disassembly,

NOTE

Tag all electrical leads removed during disassembly for positive identification during reassembly.

voltage relationships indicated by Ml and M2 are identical

to the relationships indicated by the graph in figure 8-22.

Adjust R1 to obtain this relationship.

e. Replace a defective load measuring unit, if voltage relationships do not match the graph.

8-19. Repair, Reassembly and Installation.

a. Repair. Replace load measuring unit that does not meet testing requirements.

See figure 8-20 to disassemble the load measuring unit.

8-18. Testing.

a. Connect load measuring unit in test circuit as illus-

trated in figure 8-21.

measuring unit.

c. Installation. See figure 8-1 and install the load meas-

uring unit (7) on relay table (52) with screws (5).

8-28

Change 8

Figure 8-20.

Load Measuring Unit Disassembly

ME 6115-545-34/8-20 Cl

Change l

8 - 2 9

REF

DESIGNATION

Ta, Tb, Tc

Ra, Rb, Rc

TEST EQUIPMENT

QUANTITY

DESCRIPTION

Power source 208 V, 3 phase, 47-430 Hz

* Current transformers

Load resistors 7.5 ohms, 10 watts

Load bank

Voltmeter 0-10 Vac

Voltmeter 0-50 Vdc

Voltmeter 0-300 Vac

* Shall be designed to deliver 0-5. 6 volts as load is varied from zero to full load.

8-30

Figure 8-21.

Load Measuring Unit Test, Schematic Diagram

ME 6115-545-34/8-21

TM 5-6115-545-34

I N S T R U C T I O N A L G U I D E F O R T H E M I L . D E S I G N G O V E R N O R

Figure 8-22.

Load Measuring Unit Test,

Voltage Relationship Graph

Change 8 8-31/(8-32 blank)

CHAPTER 9

GENERATOR ASSEMBLY REPAIR INSTRUCTIONS

9-1. General.

a. The main generator is a brushless type consisting of a stationary three-phase armature and a rotating salient pole wound field. The exciter, mounted integrally with the main generator, consists of a three-phase rotating armature mounted on the shaft with the generator field and a stationary salient pole field.

The exciter has ten poles.

b. A full wave bridge rectifier containing six diodes is mounted on the shaft. Access to test or replace the rectifiers is through the access hole on the end of the endbell assembly. Access to the exciter stator and rotor, and inspection of the main generator armature and field, require disassembly of the generator.

c. The generator shaft is directly driven by the engine shaft through flexible metal disk coupling.

The flexible coupling compensates for misalignment between the two shafts to eliminate injurious stress on the connecting components.

d. The main generator stator is installed in the stator frame and is fastened to and spaced by longitudinal ribs which are part of the frame. An eye bolt on the stator frame provides a means of lifting the unit. The exciter stator is mounted in an endbell which positions on the stator frame rabbit.

e. The rotor is supported at one end by a single healing in an endbell bolted to the stator frame. The opposite end of the rotor is provided with a blower assembly and coupling disk which bolts directly to the engine flywheel.

The rotor is skewed to improve generator output voltage waveform.

f. The bearing is a double-seal type ball bearing, packed with grease conforming to Specification MIL-

G-23827. It provides a minimum of 5000 hours of service at continuous loads.

9-2. Generator Removal and Disassembly.

a. Insulation Resistance. To test insulation resistance, use a megohmmeter to measure the resistance between a winding and ground. The insulation resistance of each of the windings should be at least 1 megohm at 75°F.

If this value is not met, clean or dry out the winding and repeat the test. Replace if defective.

NOTE

Low insulation resistance may be caused by dirt or excessive moisture. Insulation failure may be caused by wrong voltages, induced voltages caused by opening field circuits too quickly, oil and grease, high temperatures or excessive vibration.

(1) Generator Stator- Disconnect all leads to voltage regulator and all other points to completey isolate the winding before meggering.

(2) Generator Rotor - Disconnect both field leads from the rotating diode assembly before meggering.

(3) Exciter Stator - Disconnect both field leads from terminals 15 and 16 of TB16.

(4) Exciter Rotor - Check this only if other windings have low insulation resistance as the leads must be unsoldered from all diodes before meggering.

b. Electrical Malfunctions and Isolation. A malfunction of the main generator is usually indicated by low output voltage, or no voltage output. To isolate a malfunction to the main generator, proceed as follows:

(1) Tag and disconnect the two top leads on terminals 15 and 16 of TB16 (located on the current transformer mounting plate). Connect one side of a dc ammeter to one of the terminals (15 or 16) and an adjustable dc voltage source to the other terminal and the dc ammeter.

The adjustment shouId be set to mint mum voltage.

(2) If the set is a 50/60 Hz set, select 60 Hz and start the engine.

Bring the speed up to 1800 rpm manually and turn on the adjustable dc power supply.

Adjust the dc voltage so that the output voltage (no load) reads 208 or 416 volts (depending on low or high voltage connection).

The dc ammeter should read between 1.25 and 1.55 amperes to produce either 208 or 416 volts.

(3) If the set is a 400 Hz set, start the engine and bring it up to 2000 rpm. Turn on the adjustable dc power supply.

Adjust the dc voltage so that the output voltage (no load) reads 208 or 416 volts, (depending on low or high voltage connection). The dc ammeter should read between 3.0 and 3.65 amperes to produce either 208 or 416 volts.

(4) If the dc ammeter indicates incorrect input exciter current to obtain rated voltage in steps

(2) or (3) above, the generator has failed. Proceed with the following steps. If the output is as specified, the excitation system assembly has failed (re-

fer to paragraph 8-1).

The following steps are presented to enable isolation of the fault within the generator.

Only steps (5), (6) and (7) would normally be done without some disassembly of the generator.

(5) Remove six bolts securing air intake grille and remove griIle.

Remove screws, cover plate,

and gasket from generator endbell. See figure 9-1.

Remove bolts from the six diodes on the exciter rotor frame, one at a time, replacing each diode after testing.

Test diodes per paragraph 14-12b.

9-1

9-2

Figure 9-1. AC Generator Assembly

Key to fig. 9-1.

10.

11.

12.

13.

14.

15.

16.

Screw

Nut

Screw

Washer

Clamp assy

Screw

Plate

Gasket

Screw

Cover

Gasket

Screw

Cover

Gasket

Screw

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

Washer

Screen

Screw

Washer

Screw

Washer

Exciter assy

Screw

Clamp

Stator

Screw

Plate

Shield

Screw

Retainer

If any defective diodes are replaced, repeat step (2) or (3) above to determine if the generator defect has been corrected.

(6) Tag and disconnect the two top leads at pins

15 and 16 of TB16 (located on the current transformer mount plate).

Read the exciter field resistance at pins 15 and 16 with a Wheatstone bridge. The exciter field resistance should be between 2.90 and 3.55 ohms at an ambient temperature of 65°F.

(7) Check insulation resistance with megger be-

tween pins 15 and 16 and the frame (para 9-2a). Re-

connect the two leads and remove tags. Before proceeding further with fault isolation, disassemble the endbell from the generator.

(8) Disconnect generator rotor leads from the rotating diode assembly and measure the field resistance with a Wheatstone bridge. The resistance value for a 50/60 Hz generator should be 0.38 to

0.46 ohms and 1.17 to 1.43 ohms for a 400 Hz generator at an ambient temperature of 65°F.

9-2a).

(9) Megger between field leads and frame (para

(10) Disconnect diodes and use a double Kelvin bridge to read the resistance between leads on the exciter rotor. On a 400 Hz set, this value is 0.042

to 0.051 ohm and on a 50/60 Hz set, this value is

0.019 to 0.023 ohm at a 65°F ambient temperature.

(11) Check insulation resistance with megger

between exciter armature !eads and frame (para 9-2a).

(12) Check resistance of surge protector (varistor) when disconnected from one side of generator field. Value should be 1 megohm or more in each direction. Check to be sure no physical damage is evident on the surge protector.

(13) Tag and disconnect the twelve stator leads at the voltage reconnection panel and measure each of the six stator windings with a Kelvin double bridge.

39.

40.

41.

42.

43.

44.

45.

46.

47.

48.

33.

34.

35.

36.

37.

38.

Bearing

Cap

Screw

Washer

Cover

Gasket

Screen

Screw

Strip

Ring

Disc

Fan

Screw

Washer

55.

56.

57.

58.

59.

60.

61.

62.

63.

64.

49.

50.

51.

52.

53•

54.

65.

Deflector

Rotor assy

Hub

Key

Plate

Nut

Washer

Rectifier assy

Washer

Key

Rotor

Plate

Rotor

Screw

Plate

Eyebolt

Frame and stator assy

On a 50/60 Hz generator, the resistance should be

0.0216 to 0.0264 ohm in each circuit. On a 400 Hz set, the resistance value should be 0.0141 to 0.0173

ohm in each circuit, at ambient temperature of

65° F.

(14) Connect all stator leads together and read between the leads and the generator frame with a

megger (para 9-2a).

(15) Growler test

(a) Perform internal growler test on stator by applying 110 Vac to the coil which is wound on the cross bar of the H.

(b) Place the growler on the coil of the stator so that it is in direct contact with two adjacent slots.

(c) A shorted coil produces a very heavy current which is indicated by the rapid vibration of a thin piece of metal, such as a hacksaw blade, held over the other end of the coil.

(d) Perform a growler test on the rotor as described in (a) above.

(e) Place the rotor on the growler and energ i z e .

(f) Hold a thin piece of metal, such as a hacksaw made, directly over the top slot of the rotor and along the length of the slot. If the coil is shorted, the blade will vibrate rapidly and cause a growling noise.

(16) If the above test values are not within the limits specified, proceed with the removal and repair procedures.

c. Defective Bearing Replacement. If a defective bearing is indicated by vibration or noise at the bearing housing on the endbell, the bearing can be replaced without removal of the generator from the set.

Change 6

9-3

d . Removal of Bearing with Generator Installed.

(1) Disconnect the positive battery cable.

(2) Remove paralleling receptacle panel.

(a) Disconnect the paralleling receptacles.

(b) Tag each receptacle for proper location.

(3) Remove manual speed control panel.

(a) Disconnect flexible cable from manual speed control knob.

(b) Disconnect electrical connector from the Remote Control Box.

(4) Generator rear grille and access doors are now detached and may be removed.

(5) Remove transformer protective cover.

(6) Remove the load terminal board (TB6).

(7) Sequentially remove and tag each of the twelve generator leads on the rear of the load terminal board.

(8) Sequentially route the generator output leads back to the generator through their respective current transformers.

(See fig. 6-2)

(9) Disconnect the exciter field leads from

TB16 posts 15 and 16 and route the leads back to the generator.

(10) For removal of bearing, refer to f steps

(1) through (4) inclusive.

(11) Reassemble in reverse order of disassembly.

e . Removal. Refer to paragraph 2-12 to remove

main generator.

f . Disassembly.

See figure 9-1 and disassemble

in the order of sequence numbers observing the following.

(1) Break endbell fit by tapping on knock off lugs located in the 45 degree positions. Slide endbell axially off the bearing.

Pass stator leads through endbell opening as endbell is removed from the stator.

(2) The exciter stator maybe removed from the endbell assembly by removing or drilling out the dowel pin (26). only a small force is needed to remove the stator.

(3) Remove screw with an Allen wrench and then remove bearing retainer.

(4) Pull the bearing (33) with a suitable bearing puller and replace with new bearing.

(5) To remove the rotating diode assembly, bend up the lock tab on lockwasher and unscrew the locknut.

(6) Unscrew the generator field leads from the

plate (8), (fig. 9-2) and unsolder the six exciter

leads from the diodes. These leads should be tagged to maintain the polarity of the diodes when reassembled.

CAUTION

Use a soldering iron no larger than 100 watts and as little time and force as possible to unsolder the leads. The diodes can be damaged by excess heat or force sufficient to bend the stem or break the glass seal.

(7) The surge protector may be removed from the rotating diode assembly.

(8) After the leads are disconnected, the rec

tifier assembly (fig. 9-2), key and spring washer

will slide off the shaft.

(9) To remove the rotor assembly from the stator proceed as follows:

Slide the rotor through the stator toward the drive end far enough so that a sling may be placed under the generator field core. Hoist the rotor slightly to free it. Pull the rotor axially while applying leverage at the drive end to balance the rotor on the sling.

It may take one or two repositioning of the sling to get the sling near the center of the rotor core for proper balancing of the assembly,

(10) The exciter rotor may be removed from the shaft by using a bearing puller near the outside diameter. Be careful not to bear on windings if exciter rotor is to be reused.

(11) Balance plates are shrunk on the shaft and may be removed with heat. Apply heat with a torch to the hub of the balance plate. Move the torch around the periphery of the hub using care not to apply the torch to the shaft. The balance plate bore will expand and the balance plate may be removed manually.

(12) The coupling hub is shrunk fit on the shaft.

To remove, use a cutting torch to cut through the hub at the keyway to prevent shaft damage. After cutting through, use a chisel in the cut to open the bore and remove the hub.

( 1 3 ) T h e g e n e r a t o r s t a t o r c o r e i s n o t t o b e r e - moved from the stat or frame because the concentricity between bore and rabbit fits would be disturbed and cause voltage modulation problems. When removing the rotor stack from the shaft, remove in the direction, that the stack was pressed on.

9-4

1. Nut

2. Washer

3. Rectifier

4. Rectifier

9-3. Generator Cleaning and Inspection.

a. Cleaning. Clean all metal parts with Federal

Specification P-D-680 and dry thoroughly. Uses clean cloth to clean the stator frame. Use low pressure compressed air (10 to 15 pounds pressure) to remove dust and dirt from inside the frame and core, and from the rotor windings.

b. Inspection. Proceed as follows

(1) Inspect stator frame for cracks and burred mating surfaces.

(2) Inspect rotor and stator of generator and exciter for loose, frayed, or burned windings.

(3) Inspect coupling disks and fan for distortion and excessive wear.

(4) Inspect for missing or defective hardware.

(5) Inspect rotating diode assembly for broken

diode cases. Test diodes per paragraph 14-10.

9-4. Generator Repair and Rebuild.

a. Generator Repair. Proceed as follows:

(1) Replace or rebuild all defective parts (re-

fer to paragraph 9-2d for disassembly information.)

Figure 9-2. Rectifier Assembly

5. (Deleted)

6. Washer

7. Surge protector

8. Plate

ME 6115-545-34/9-2 C1

To remove coils from an iron core, it is recommended that the part be heated in a moderate oven temperature (1500 C) to facilitate removal. Single coils should not be replaced as adjacent parts of the winding may be damaged during coil removal.

(2) Apply varnish to any damaged areas of insulation.

(3) Replace damaged exciter rotor or stator.

b. Generator Rebuilding (50/60 Hz). Proceed as follows:

(1) Stator winding procedures.

(a) Single wires may be spliced by brazing.

The splice is to be insulated by sliding sleeving over the wire prior to brazing and relocating the sleeving over the splice after completion. The sleeving is to extend a minimum of 1/2-inch beyond the bare uninsulated portion of wire. The sleeting material i

S to be the same as that used for cross-overs on the connection end. Splices shall be made in the end turn of the coil only and shall not be made in the straight leg. Where more than one splice is required, the second splice must not occur on the same coil end and must not occur in adjacent coils. Where more than one splice is necessary in the same coil or an adjacent coil, the splice may be made in the connection end of the coil.

Change 1 9-5

(b) Enamel is to be cleaned from coil extensions. Cleaning is to start as near sleeving as possible. Clean a 1/2-inch section of wire end projecting from a sleeving.

Maximum uncleaned wire projecting from a sleeving section shall be 3 inches minimum to 5 inches maximum. Wire diameter is to be reduced a maximum of 5 percent. Cleaned area shall have enamel removed over 80 percent of the surface.

(c) Slot tubes should be inserted with overhang equally divided on ends. Minimum slot tube overhang (distance from core to end of slut tube) shall be 1/4 inch. Position of the tubes should be

adjusted so that height of sides is equal. (fig. 9-3)

(d) After the slot tubes have been inserted, insulating tape shall be placed into the stator to form a bridge between slot tubes. It will be placed so as to bridge every other tooth in the stator core in one continuous length by stringing it through one slot, crossing over at the end of the slot to the next slot, back through and on to the third slot, continuing until it is back at the starting point. The starting and finish ends shall be securely tied together.

This bridge is to restrain the end turn tie cord.

(e) Coils shall be inserted in slots so that overhanging ends are equally spaced. Wire bundles at entrance to slot should be brought out as straight and compactly as possible to reduce side pull on overhanging slot tube ends.

(f) Care should be taken to see that wire insulation is not scratched or otherwise damaged. Coil wires should not be kinked or crossed in the slots.

Tools inserted into slots to adjust position of wires or separators should be free from burrs or sharp edges to prevent damage to wire or slot insulation.

If it is necessary to use a mallet when tamping down wires or separators in slots, tap the slot tools lightly. Heavy pounding will ruin the insulation.

(g) After bottom coil sides are in the slots, the separators are wedged in place with their overhanging ends equally spaced. These ends should project approximately 1-1/2 inches from edge of core.

The separators should fit tightly enough to hold the coils down in the slots.

(h) Phase insulating strips are placed in the end turns to insulate between the coil groups on both ends of the winding.

These strips should be placed so that the back edge reaches the ends of the wedges approximately 1/2 inch from core. The strips will then overlap the ends of the separators. After coil ends are properly shaped, trim phase insulating strips all around so that 1/16 to 1/4 inch of edge projects beyond edge of wires.

Phase insulating strips may extend 1/2 inch beyond wire on coil outer diameters.

(i) Top sticks shall be carefully inserted so that slot fibes and wire are not damaged. The overhanging ends should be equal and they should be level.

Top sticks which are broken or split during insertion should be replaced.

9-6

Change 4

(j) Connections shall be twisted together and brazed using brazing alloy. The distance from the first twist to the film coating on the wire must not exceed 1-1/2 inches.

End of connection forming pigtail shall be fusion welded as much as possible with addition of alloy.

When coil pole leads and ends consist of multiple wires, care must be taken to insure that each wire is securely connected. All sharp wire ends or spikes of solder remaining on brazed joints should be trimmed off or flattened down to prevent puncturing of insulation tape.

(k) When connectors are used instead of brazing connections, wire must extend completely through the connector.

The connector should be located as close to the insulated portion of the wire as is possible. Connectors must be applied using a wire crimping tool -- crimping is not to be done using pliers, hammers or other make-shift arrangements.

(1) Sleeving must be positioned to cover the coil extension from the coil to which it is attached to a point at least 1/2 inch under two layers of tape.

The sleeving at the coil end must be positioned to provide a minimum of 3/8-inch creepage path from the coil extension to adjacent coils.

(m) All connections in stator winding shall be covered-with sleeving, MIL-I-3190/3. Where tape is wide enough to cover the uninsulated wire and extend a minimum of 1/2 inch over insulated portion of wire, wrap one layer of tape over the connection, pressing the two adhesive sides together for approximately

1/4 inch. The remaining length of tape should be long enough to make two or more wraps over the connection. The connection and any uninsulated part of the wires adjacent to the connection will be covered with three thicknesses of tape.

(n) Where the tape is not wide enough to provide coverage for the connection, the tape shall be wrapped around the connection such as to provide l/2-inch lap plus 1/8 inch (minimum). The overlap is to be such as to provide a minimum of two layers of tape. The double layer of tape is to extend a minimum of 1/2 inch over the insulated portion of wire.

(o) Stator windings will be tied on lead end

Only.

Use a hitch or chain stitch tie. Spacing between ties is not to exceed 3 inches. A tie must be made over each connection. Tie on either side of cable bundle will be a double lace.

Tie must pass through space between coils bridged by tape specified

(P) End turns on opposite lead side will not be tied. However, the string ties, placed on the individual coils during coil winding operation, will be left on untaped coil after insertion, to help keep wires from being displaced.

(q) Refer to table 9-1 for winding data.

(2) Stator dip and bake (50/60 Hz).

Type of winding

No. of slots and coils

No. of coils per group

Turns per coil

Span

Conductor

Connection

Resistance

Table 9-1. Stator Winding Data (50/60 Hz)

3 phase, dual voltage

84 slots 84 coils

1-15

6 of AWG #15 (0. 0571 dia)

4.2 ckt, (See fig. 9-3)

0.026 ohm at 25° (T1-T4, etc.)

(a) Preheat wound core for 1 1/2 hours (2 hours maximum) in forced convection oven maintained at 170° C.

(b) Cool core down to a temperature of 1050 to 115° C and dip at this temperature-into varnish, connection end up, until all bubbling stops, or for 3 minutes, whichever is longer.

(d) Rotate wound core so connection end is down and drain for one minute.

(e) Bake wound core with slots in horizontal position for 2 hours in forced convection oven maintained at 170° C.

(f) Repeat steps b,

, d, e and f two times so that a total of three dips and bakes are performed.

(g) The wound stator should be examined for complete coverage, uniform coverage with no strings or beads and with openings between extended position of slot tubes, free of varnish, blistering or peeling, and complete cure with tack-free surface and good bonding strength.

(3) Rotor coil winding.

(a) Inspect winding slots for any sharp corners at edge and in slot. Clean up as necessary.

(b) Screw support studs into tapped holes

at bottom on slots. See figure 9-4.

(c) Examine the bore and determine the direction in which it was removed. Place the leads on the end where the shaft left the bore. This is so the shaft can be pressed thru the bore in the direction it was removed.

The center of the rotor stack must be located 11.48 inches from the hub end of the shaft.

(d) Insert slot liners as the poles are wound.

Hold in place with sacrifice adhesive tape.

(e) With the rotor body turning on the machine, guide the wire into the slots for the specified number of turns. Hold the wire with enough tension on the tension blocks to assure a hard firm winding.

Traverse the wire at the end turns and not in the slot, as much as possible. This prevents excessive build up of the wire in the slot.

(f) Place one spacer tool at the end of stack and another in the approximate middle of the winding.

(g) Place winding clamp in position over stud and force into position so that nut can be tightened over end of stud.

(h) Connect poles and leads per connection

diagram. See figure 9-4. Use cold connectors and

insulate with tubing.

(i) Tie the end turns with glass roving.

(j) Seal all knots by momentarily pressing with “hot” pliers long enough to fuse the roving.

Heat pliers in gas flame to “Black Heat” about

300° F.

(4) Rotor dip and bake.

(a) Preback wound core for one hour in forced convection oven at 165° C.

(b) Dip hot wound core in varnish for one minute with leads up.

(d) Rotate wound core with leads down and drain for one minute.

9-11

Table 9-2. Rotor Winding Data (50/60 Hz)

Resistance 0.390 ohms at 25° C

Connection

Conductor

1 circuit (refer to fig. 9-4)

9 of AWG #16 (0.0508)

Turns per coil

No. of poles and coils

103

(e) Reverse wound core so leads are horizontal and bake for one hour in forced convection over at 165° C.

(f) Repeat steps b, c, d, and e two times so that a total of three dips and takes are performed.

(g) The varnished wound rotor core should be examined for complete coverage, uniform coverage with no strings or beads and with openings between extended position of slot tubes free of varnish, blistering or peeling, and complete cure, with tackfree surface and good bonding strength.

c. Generator Rebuilding (400 Hz). Proceed as follows:

(1) Stator coil winding procedures. See figure

9-5 and table 9-3, and perform the procedures pro-

vided in step b (1).

(2) Stator dip and bake. Perform the procedure defined in step b (2).

(3) Rotor coil winding.

(a) Inspect winding slots for any sharp corners at edge and in slot. Clean up as necessary.

(b) Examine bore and determine the direction in which the broach passed through the bore.

Place the leads on the end where the broach left the bore. This is so the shaft will be pressed through the bore in the same direction as the broach.

See figure 9-6.

(d) Insert the coils in the usual manner.

Position the coils as evenly as possible on each end.

Consult the coil limit diagram to be sure that the two ends are adjusted to allow room for the connections, which must be within the coil limit diagram.

(e) Insert tapered edge top stick and drive into position.

(f) Make interpole and lead connections as

required by internal connection diagram. See figure 9-6.

(g) Over each end, turn-wrap 20 turns of double glass roving to provide banding support of end turns.

(h) With double roving, loop over the banding and connnections and run on continuous piece of double roving over all 24 coil ends. Burn all knots with red hot duck bill pliers.

(i) Refer to table 9-4 for 400 Hz rotor

winding data.

Table 9-3. Stator Winding Data (400 Hz)

Type of winding

No. Of slots and coils

No. of coils per group

Turns per coil

Span

Conductor

Connection

Resistance

3 phase, dual voltage

108 slots 108 coils

36 groups of 2 and 36 groups of 1

1-4

AWG #16 (0.0508) and AWG #17 (0.0453)

12/6 ckt, (see fig. 9-5)

0.017 ohm at 25° C (T1-T4, etc.)

9-12

9-17

Figure 9-5. Stator Winding and Coil Connection (400 Hz)

(Sheet 2 of 2)

Resistance

Connection

Conductor

Turns per coil

Table 9-4. Rotor Winding Data (400 Hz)

No. of pole and coils

1.43 ohms at 25° C

1 ckt, series, see schematic diagram

4 of AWG #15 (0.0571)

(4) Rotor dip and bake.

— forced convection oven to 170° C.

(b) Dip hot wound core in varnish, connection end up, for three minutes.

(d) Rotate wound core so connection end is down and drain one minute.

(e) Bake wound core with slots in horizontal position for two and one-half hours, at 170° C, in forced convection oven.

(f) Repeat paragraphs (b) through (e) above two more times so that a total of 3 dips and bakes is applied.

(g) The varnished wound rotor should be examined for complete coverage, uniform coverage with no strings or bends and with openings between extended position of slot tubes free of varnish, blistering or peeling, and complete cure, with tack-free surface and good bonding strength.

9-5.

Exciter Repair and Rebuild.

Repair.

(1) Replace or rebuild any defective parts.

(2) Apply varnish to any damaged areas of insulation.

(1) Exciter stator. See figure 9-7 and table

9-5, and perform the procedures provided in paragraph 9-4 (1) and (2).

(2) Exciter rotor.

alloy per above.

Proceed as follows

(a) All wound cores will have leads connected and tied on the inside diameter of end turns.

(b) All connections will be brazed using brazing alloy per MIL-S-15395 as a filler material.

End connections forming pigtails will be fusion welded as much as possible with addition of brazing

(c) All connections in the rotor winding will be covered with sleeving MIL-I-3190/3. Tape should be 1/2-inch lapped over connections and extended 3/8- inch beyond connection.

(d) For binding end turns use glass roving.

(e) The rotor end turns and connections are bound and laced in two stages.

Table 9-5. Exciter Stator Winding Data (50/60 and 400 Hz)

Type of winding

No. of slots and coils

No. of coils per group

Turns per coil

Span

Conductor

Resistance

Connection

Salient pole, dc

10 slots 10 coils

196

1 - 2

1 of AWG #21 (0. 0285) 1 of AWG #22 (0. 0253)

3.2 ohms at 25° C

2 circuit (see fig. 9-7)

9-18

Change 4

(f) Using a zig-zag motion, place a band of one continuous piece over and near the end of the end turns.

Using enough spread to keep the band below the line of the rotor outer diameter, secure the end by lapping over the end. Binding must not be loose.

(g) After all coils are inserted and bound as in (a) above, lace continuously using at least two turns at each location with a slip tie on the second turn. Lace at each tooth, separating the top coils and the bottom coils.

(h) Place the connection bundle beneath the end turns and lace as in (g), being sure to lace in the connection bundle.

(i) Refer to table 9-6 and figure 9-8 for

exciter rotor winding data.

9-6. Generator Reassembly and Installation.

a. Reassembly.

See figure 9-1 to reassemble

the ac generator.

(1) Balance plates should be shrunk on the shaft. Heat balance plates in an oven to approximately 200° C.

Place heated balance plate on shaft and with a pipe or sleeve with a bore slightly larger than the balance plate bore, tap the balance plate onto the shaft until it registers against the shaft shoulder.

(2) The coupling hub is reassembled to the rotor assembly by placing the hub in an oven and heating to 200° C.

The hot coupling hub then slides on the shaft and key.

(3) The diodes should be placed on the rotating diode assembly, using a thermal conduction lubricant such as Burndy “Penetrox A“ or equivalent. Do not allow the lubricant on the threads of the diode or the torque measurements will be incorrect.

There are three forward polarity diodes

(arrow towards threaded stud) and three reverse polarity diodes (arrow away from threaded stud). The diodes must be assembled with the three forward polarity diodes on one heat sink and the three reverse polarity diodes on the other heat sink. Assemble the diodes with nuts and lockwashers, using a torque wrench.

Assemble with 30 inch pounds of torque.

(4) Use balance weights assembled in holes of balance plate to dynamically balance complete rotor assembly within 2 inch-ounces.

(5) Tighten screw (41) to 950-1100 inchpounds and bend up corners of strips (42) against a flat side of screw (41).

(6) At assembly apply light coating of grease

(MIL-G23827) to the bearing bore of the end shield. Also add 0.9 to 1/4 cu. in. (1.0-1.5

tablespoons) of grease to the bearing cavity on the outboard side of the bearing and 0.45 to 0.7 cu. in.

(0.5 to 0.75 tablespoons) of grease to the bearing cavity on the inboard side of the bearing.

b. Installation Refer to paragraph 2-12.

9-7. Generator Tests after Reassembly.

Perform tests 1, 2 and 3 of operating tests (refer to

table 16-1).

CAUTION

Table 9-6. Exciter Rotor Winding Data (50/60 and 400 Hz)

Type of winding

No. of slots and coils

No. of coils per group

Turns per coil

Span

Conductor

Connection

Resistance

Insertion sequence

3 phase

36 slots 36 coils

6 groups of 2 24 groups of 1

3 for 50/60 Hz -5 for 400 Hz

1-4

5 of AWG #16 (0.0508) - 50/60 H

3 of AWG #16 (0.0508) -400 Hz

Parallel 2 circuit WYE, (see fig. 9-8)

0.023 ohm at 25° C - 50/60 Hz

0.050 ohm at 25° C -400 Hz

211/112/111/121/111 and repeat

Change 4

9-25/(9-26 blank)

CHAPTER 10

10-1. General.

DAY TANK ASSEMBLY REPAIR INSTRUCTIONS

(3) Flush tank thoroughly with hot water or steam under pressure.

Clean interior with solvent and dry thoroughly.

a. The day tank is provided to receive fuel from the–main fuel tank through the fuel transfer pump and primary fuel filters and to supply fuel to the fuel injection pump via the secondary fuel filter.

b . Inspection

(1) Inspect hardware and thread areas for damage.

b. The day tank is mounted on a support bracket above the fuel injection pump on the right side of the engine. Fuel is transferred by two electric pumps from the main fuel tank to the day tank.

(2) Inspect fuel passages for obstructions.

(3) Inspect interior to insure that scale and sediment have been removed.

10-2.

Removal.

Refer nance to the Operator and Organizational Mainte-

Manual to remove the day tank.

c . R e p a i r .

(1) Repair all threaded areas with a fine mill file. Retap threaded holes.

10-3.

Cleaning, Inspect ion and Repair.

Cleaning.

(2) Use compressed air to clear fuel passages.

(1) Clean exterior of day tank with cleaning solvent, Federal Specification P-D-680 and dry thoroughly.

10.4 Installation.

Refer to the Operator and Organizational Maintenance

Manual.

(2) Remove all gasket and adhesive materials from mating surfaces.

10-1/(10-2 blank)

11-1. General.

The lifting frame provides center support for the housing and mounts to lift eye devices for hoisting.

11-2. Removal and Disassembly.

a. Remove generator set housing and lifting frame components.

Refer to the Operator and Organizational Maintenance Manual.

b. Refer to Operator and Organizational Maintenance Manual and remove the fuel tank to allow removal of bottom bolts holding supports. (30 and

31, fig. 11-1.)

c. Remove and disassemble the lifting frame as

illustrated in figure 11-1.

11-3.

Cleaning and Inspection.

Refer to Operator and Organizational Maintenance

Manual.

a. Clean the lifting frame with cleaning solvent,

Federal Specification P-D-680.

b. Use a stiff bristled brush to remove heavily concentrated grease and dirt.

c. Inspect the lifting frame for cracks and distortion.

11-4.

Repair.

Repair the lifting frame by replacement of damaged

parts. (fig. 11-1.)

11-5.

Reassembly and Installation.

Reassemble and install lifting frame in reverse order

of disassembly. (fig. 11-1.)

CHAPTER 11

LIFTING FRAME REPAIR INSTRUCTIONS

KEY to Fig. 11-1.

Nut

Washer

Screw

Bracket

Nut

Washer

Screw

Washer

Bracket

Nut

Washer

Screw

Nut

Washer

Screw

Nut

Washer

Screw

Bracket

Screw

Washer

Nut

Washer

Screw

Washer

Nut support support

Rivet

Plate

21.

22.

23.

24.

25.

15.

16.

17.

18.

19.

20.

26.

27.

28.

10.

11.

12.

13.

14.

29.

30.

31.

32.

33.

11-1

11-2 Change 7

ME 6115 545-34/11-1 C7

Figure 11-1. Lifting Frame Assembly

CHAPTER 12

COOLING GROUP REPAIR INSTRUCTIONS

12-1. General.

a. The cooling group consists of the radiator grille, shutter assembly and the shutter thermostat.

b. The radiator is mounted at the front end of the engine generator set just behind the grille and shutter assembly. It is equipped with inlet and outlet hose connections, a filler cap and an overflow tube. A drain valve is located on the lower right side of the radiator. A shroud and fan guard are mounted on each side behind the radiator, enclosing the fan.

The radiator shutter is mounted on the front of the radiator. The shutter control is mounted on the lower right side of the radiator and operates by thermal expansion.

A plunger inside the thermostat, which is affected by temperature in the radiator, actuates the linkage system to the shutter. The shutter will remain closed until the engine warms up, at which time it will open upon action of the shutter control.

A control lever is provided for manual operation of the shutter control in case of thermostat failure.

d. The fan is located behind the radiator on the front of the engine.

Driven by belts when the engine is running the fan draws cooling air through the doors at the rear of the unit and exhausts it through the radiator core, shutter and grille.

12-2. Radiator Assembly Removal.

A malfunction of the radiator, shutter assembly or thermostat is usually indicated by an abnormally high reading on the coolant temperature gauge located on the engine control panel.

To isolate the cause proceed as follows: a. If the shutter assembly is closed, operate the manual control and open it. If the temperature begins to drop toward normal, the probable cause is a faulty shutter thermostat. (Refer to the Operator and

Organizational Maintenance Manual).

b. Open the radiator fill cap and check for a suffcient amount of coolant. Add coolant if necessary and observe temperature gauge for a drop in temperature.

. Shut the engine down. Examine the pulley belts for tension. If they are tight examine the fan for bent or broken blades and freedom of motion.

d. When it is determined that there has been a failure of the radiator, fan, or shutter assembly, remove the radiator, grille, shutter assembly, shroud and fan guard. (Refer to the Operator and

Organizational Maintainance Manual).

12-3. Radiator and Shutter Repair and Test.

a. Clean all parts with cleaning solvent Federal specification P-D-680 and dry thoroughly with compressed air at 10 to 15 pounds pressure.

b. Inspect all hardware and threaded areas for damaged or crossed threads.

c. Inspect shutter control body for damage and proper operation.

d. Repair control assembly and shutter assembly

by Emplacement of defective parts. (See figures 12-1

and 12-2).

Using compressed air, remove all dirt and foreign material from the radiator core.

(1) Solder or braze any radiator core leaks.

(2) Straighten bent cooling fins.

f. Replace all worn, damaged, or defective parts.

g. Test the radiator for leaks by placing the radiator with outlet connection sealed in a tank of water.

Apply compressed air of 10 to 15 psi at filler opening and observe for leakage indicated by air bubbles in the water.

12-4. Radiator Assembly Installation.

Install the fan guard, shroud, radiator, shutter assembly, grille and shutter thermostat. (Refer to the

Operator and Organizational Maintenance Manual. )

12-1

12-2 Change 1

Setscrew

15. Pin

Ring, Retaining

16. Plunger shaft

17. Bearing

Yoke and plunger 18. Yoke a s s y 19. Power element and flange assy.

Figure 12-1. Control Assembly

Nut

Preformed packing

Retaining ring

Seat

F e l t

30. Seat

31. Spring

32. Seat

33. Bushing

34. Flange

ME 6115-545-34/12-1 Cl

1. Spring

2. Nut

3. Retaining ring

4. Rod Assy

5. Pin

6. Block

Figure 12-2. Shutter Assembly

10.

11.

12.

Spring

Rod

Tape

Rivet

Vane Assy

Shutter Assy

ME 6115-545-34/12-2

C1

Change 1 12-3(12-4 blank)

CHAPTER 13

HYDRAULIC ACTUATOR, SUMP AND FILTER REPAIR INSTRUCTIONS

Section I. HYDRAULIC ACTUATOR (CLASS I, PRECISE SETS ONLY)

13-1. General.

The hydraulic actuator (figures 13-1 and 13-2) is part

of the generator set electro-hydraulic governing

system (para. 7-1 and 7-2) and is used to control the

speed of the generator set. An error voltage sensed by the governor system control unit is magnetically amplified to control the power to energize the solenoid of the hydraulic actuator, thus changing the high pressure input oil into a differential pressure across the piston. This is accomplished by a solenoid controlled teeter bar within the actuator that controls the position of the actuator piston.

13-2. Malfunction.

A malfunction of the hydraulic throttle actuator is usually indicated by engine shutdown or overspeed when the START- STOP-RUN switch is transferred from the START to the RUN position, frequency drift observed on the frequency meters, sluggish response to load changes, or no response to load changes. To isolate the malfunction, proceed as follows a. Check for 4-6 Vdc at test points AB and CD

(see figures 1-4 and 1-5) of electric governor control

unit (A and D are positive), with engine operating. If voltage at either point is approximately 15 volts, the malfunction is a result of an opening in an actuator valve coil, or connecting circuit.

b. Check that the throttle linkage (see figure 13-1)

is not badly worn or disconnected. A worn linkage can cause sluggish response or drifting frequency. A disconnected or broken linkage can cause overspeed, shutdown, or no response. Also check linkage for binding due to dirt or distortion.

c. Check condition of hydraulic filter and the level of hydraulic oil.

Either a clogged or dirty filter or low oil level can reduce the hydraulic pressure required to operate the actuator.

d. Check pressure output of hydraulic actuator by removing plugs in ports Al and A2 and inserting

0-400 psi range gages.

The pressure at each port should be 160 + 25 psi and equal, with engine operating under governor control. Operating under manual control, with J6 disconnected, the pressure at port

A2 should be 180 + 20 psi and approximately 50 psi higher than the pressure at port Al.

e. Check the transducer in the actuator far freedom of movement. The transducer must move freely for good response.

f. If any of the above examinations indicates that the–actuator has failed, proceed with removal, disassembly and repair instructions.

13-3. Removal and Disassembly.

a. Clean all hydraulic fittings and couplings throughly to prevent contamination of system b. Remove drain plug on bottom of hydraulic sump and drain and discard hydraulic oil (Refer to

Operator and Organizational Maintenance Manual for draining procedures.) c. Remove hydraulic actuator as illustrated in

figure 13-1.

d. Remove four bolts securing bracket to activator and remove bracket.

13-2

Disassemble actuator as illustrated in figure

f .

wires

To remove connector (34) tag and unsolder all attached to connector.

13-4.

Cleaning, Inspection and Repair.

Clean all parts thoroughlv with cleaning solvent Federal Specification

P-D-680 and dry thoroughly.

b. Inspect all parts for damage or defective condition.

co wear.

Inspect ball joints and linkage for excessive d.

age;

Inspect actuator packing and piston for dam-

13-5.

Replace all defective parts.

Reassembly and Installation.

ted in

Reassemble the hydraulic actuator as illustrafigure 13-2.

Install set screw (37) in core assemblv (40) finger tight.

Then install locknut (36). Proceed with care.

. When installing connector (13), locate keyway

at 12 o’clock position. (See figure 13-2.)

d. When installing connector (34), locate keyway at 6 o’clock position, viewed from top of valve block

(48). (See figure 13-2.)

13-6. Actuator Valve and Piston Test.

13-1

13-2

1. Nut

2. Screw

3. Rod end

4. Nut

5. Rod

6. Nut

7. Screw

8. Nut

9. Rod end

10. Clevis

11. Nut

12. Screw

13. Hydraulic actuator

14. Screw

15. Washer

16. Bracket

ME 6115-545-34/13-1

Figure 13-1. Hydraulic Actuator and Related Parts

Screw

W a s h e r 1 1 .

Cover 13.

G a s k e t 1 4 .

Setscrew 15.

screw 16.

W a s h e r 1 7 .

9 .

Setscrew 19.

10. Screw 20.

Washer

Spacer

Connector

21.

22.

23.

Transducer assembly 24.

Core

25.

Retaining ring

26.

Washer

27.

Packing

Collar

28.

29.

Quad-ring

30.

Piston

Retaining ring

Washer

Packing

Collar

Quad-ring

Filter plug assy

Packing

Plug

31.

32.

33.

34.

35.

36.

37.

38.

39.

40.

Packing

Screw

Washer

Connector

Gasket

Nut

Setscrew

Screw

Washer

Core armature assembly

41.

42.

43.

44.

45.

46.

47.

48.

Valve

Restrictor

Packing

Valve

Spacer

Restrictor

Packing

Block

ME 6115-545-34/13-2

Figure 13-2. Hydraulic Actuator

13-3

a. See figure 13-3 to perform the valve and piston

test.

b. Connect dc power supply (ps) and switch (S1) to J6 as illustrated. Connect voltmeter (Ml) with resistor (Rl) to pins A and B of J4.

c. Attach gage G1 and G2 as shown. Connect hydraulic power source (310-320 psi, 2 gpm) and gage

G3 and provide a return line from port R to the hydraulic sump.

d. To adjust the valves, remove the large round cover and replace it with a similar diameter collar which will allow access to the adjustment screws and jam nuts. This is necessary to contain the hydraulic fluid which is ported within this cover.

e. With hydraulic power but no electric power, applied, adjust the valve with Allen set screw to yield 200 psi - 10 psi at Al port (gage Gl) and 150 psi

+ 10 psi at A2 port (gage G2). (See figure 13-3.)

CAUTION Avoid overadjusting to prevent pressures or forces which could bend valve push rods.

f. After adjusting, lock Allen adjusting screws with jam nuts, and install cover.

g. Set S1 to the center position (solenoid coils in series). Apply 350 ± 20 ma through the coils. Pressures at Al and A2 ports shall remain the same

(para 13-6.e).

h. Set switch Sl to connect power (PS) to coil L2 and apply 700 ma ± 40 ma. Pressure at Al port

(gage Gl) shall be 310 to 400 psi. pressure at A2 port (gage G2) shall be 0 to 20 psi.

i .

Set switch Sl to connect power (PS) to coil L1 and apply 700 ma ± 40 ma. Pressure at Al port

(gage Gl) shall be 0 to 40 psi and pressure at A2 port (gage G2) shall be 310 to 400 psi.

13-7. Throttle Position Transducer Test.

a. With voltmeter (Ml), resistor (Rl) and 120

(+ 1%, 60 Hz) power source connected as shown in

figure 13-3, move piston to fully open throttle pos-

ition.

b. With the transducer body locked in place by its set screw, loosen the transducer core set screw and move the core relative to the body until a minimum voltage (0, 5 to 2.5 volts) is obtained on the transducer secondary, as indicated on Ml.

c. Move the piston gradually towards the fully closed throttle position.

The transducer secondary voltage, indicated by meter Ml shall increase in a linear manner to a maximum of 48 to 55 volts.

d. Repeat these adjustments until the transducer secondary voltage increases linearly from the lowest possible value to a maximum value over the entire 1.0 inch displacement of the piston.

13-4 e. When final adjustment is made, lock the transducer core in place with the transducer core set screw.

f. Remove the gages, meter, and power supplies.

13-8. Installation.

a. Install the hydraulic actuator with attaching

hardware. (fig. 13-1.)

b. Connect hydraulic pressure and return lines to the–actuator pressure and return parts. Different line sizes prevent inadvertent crossing of lines.

(fig. 13-2. )

. Connect electrical connectors J24 and J25.

Electrical connectors cannot be interchanged due to

differing number of pins. (fig. 13-2.)

Attach rod-ends, shaft and clevis.

13-9

Adjust the linkage in accordance with para.

13-9.

Throttle Linkage Adjustment.

Place the Stop-Run-Start switch in the RUN position. (DO NOT

- start the set.) b. Place the battle short switch in the OVER-

RIDE or UP position.

c. Remove the bolt connecting the linkage rod to the fuel injection pump shut-off arm.

d. Starting at the full counter clockwise position, move the fuel injection pump shut -off arm clockwise until a slight resistance is felt. When this resistance is felt, hold the shut-off arm in that position.

NOTE

This resistance is the fuel injection pump linkage coming into contact with the arm which moves the metering valve and starts in the direction of no fuel.

e. Move the actuator piston to the full OPEN

(DOWN) position.

f. Make the necessary adjustment to the linkage rod, such that it will fit between the actuator piston and the fuel injection pump shut-off arm.

g. Start the generator set. Refer to the Operator and Organizational Maintenance Manual.

h. Observe the frequency meter on the panel in the control cubicle.

Figure 13-3. Hydraulic Actuator Tests, Schematic Diagram

Change 1 13-5

i. Adjust the governor in accordance with

para. 7-8.

j. (Delete)

13-10. General.

Section II. HYDRAULIC SUMP AND FILTER (CLASS 1, PRECISE SETS ONLY) a. The hydraulic sump is mounted on the left side of the engine, on Class 1 precise generator sets.

The sump acts as a reservoir for the hydraulic oil pump, used to supply hydraulic power to the hydraulic throttle actuator.

b. The hydraulic oil filter is mounted on the sump and provides predection against contaminant in the hydraulic oil pressure system.

13-11. Removal, Cleaning and Inspection.

Refer to the Operator and Organizational Maintenance

Manual.

13-12. Repairs.

a. Repair threaded holes by retapping.

b. Repair cracks by welding.

c. Replace all defective parts.

d. Replace a defective filter.

13-13. Equipment Test.

If the electro-hydraulic actuator has been renewed

or repaired, refer to Chapter 16, Section II and

conduct the following tests.

a. Frequency and voltage regulation, stability,

and transient response test, short term. (para

16-15. )

b. Frequency adjustment range test.

(para

16-16.)

13-6 Change 1

CHAPTER 14

ENGINE ASSEMBLY AND COMPONENTS REPAIR INSTRUCTIONS

14-1. General.

The engine assembly provides the mechanical power to drive the main generator. It consists of a six-cylinder, turbocharged, diesel engine; batterycharging alternator, speed switch, electric starter and fuel pump. In addition, on precise generator sets, a hydraulic pump is provided. Maintenance instructions for the components of the engine assembly are provided in Sections II through XVII.

14-2. Removal.

Refer to paragraph 2-13 and remove the engine as-

sembly, if required for the repair action to be taken.

14-3. Disassembly.

a. Place engine assembly on an engine stand utilizing engine stand adapter plate and spacers.

b. Disassemble the engine to the extent required by following procedures given in Sections 11 through

XVII.

14-4. Inspection and Repair.

Inspect and repair engine assembly assemblies, subassemblies, and components as described in

Sections II through XVII.

14-5. Reassembly.

Reassemble the engine assembly by following the procedures provided in Sections II through XVII.

14-6. Testing.

a. Service engine lube oil and fuel systems with proper oil and fuel.

(Refer to Operator and Organizational Maintenance Manual.) b. Connect engine assembly to a suitable engine dynamometer equipped with a cooling system and means of monitoring engine oil pressure, coolant temperature, and engine rpm.

c. Pre-run Checks.

(1) Manually turn engine over a minimum of two revolutions and check for binding and mechanical interference. Correct cause of any binding or interference prior to starting.

(2) With the fuel injection pump solenoid

Section I. ENGINE ASSEMBLY de-energized, crank the engine until oil pressure appears on the oil pressure gauge. Crank the engine an additional 15 seconds to insure 061 is in all parts of the lube oil system.

(3) Recheck oil level and top off lube oil sump.

d. Engine Oerational Check

(1) With the dynamometer throttle set to the idle position and the fuel injection pump solenoid energized, crank the engine until the engine starts.

(2) Allow the engine to run at idle for 30 seconds, shut down engine and inspect for signs of leakage.

(3) Restart engine and allow to run at low idle for 10 minutes.

NOTE

Monitor oil pressure and coolant temperature at all times during this test, also check for unusual noise or vibrations. If at any time the oil pressure falls below 20 psi, the coolant temperature exceeds 222° F, or if noise or vibrations occur, discontinue test run.

(4) Operate engine at 1800 rpm at 1/2 load for

30 minutes.

(5) Operate the engine at 1800 rpm at full rated load for 1 hour.

(6) Check to see that the engine the following brake horsepower.

will produce

1500 rpm -

1800 rpm -

2000 rpm -

100 bhp

120 bhp

130 bhp

(7) Operate the engine with no load for five minutes at 1800 rpm.

(8) Shut down and inspect engine for coolant, oil and leaks.

14-7. Installation.

Refer to paragraph 2-14 and install the engine as-

sembly in the generator set.

Change 6

14-1

Section II. BATTERY CHARGING ALTERNATOR

14-8. General.

a. The 28 volt, 35 ampere battery charging alternator system is specifically designed for applications which require enclosed brush and slip ring construction. All of the aluminum casting and exposed parts are coated or plated to prevent corrosion. Both front and rear bearings are sealed and lubricated for life.

b. The brush assembly, enclosed by the rear housing cover, positions the brushes and provides the necessary pressure for good electrical contact with the slip rings. The voltage adjusting rheostat is a screwdriver adjustment accessible through a hole in the rear cover of the alternator. Remove battery charging alternator in accordance with Operator and

Organizational Maintenance Manual.

14-9. On Equipment Test.

a. Rear Cover Removal.

With the engine generator get stopped remove the 3 self tapping screws securing the rear cover of the battery charging alternator to the alternator housing. Remove the

rear cover plate and leave it suspended by the attached wiring. Remove the 40 ampere fuse from its receptacle.

CAUTION

Insulate all wiring to the rear cover plate by inserting insulating material between the alternator housing and wiring to the rear cover plate.

b. Voltage Regulator Test Connections. Connect the test equipment to the alternator as shown in

figure 14-1.

(5) Shut down the engine-generator set and disconnect the test equipment.

d. Alternator Output Test Connections. Connect

the test equipment to the alternator as shown in figure

14-1.

(1) This test will determine if the alternator is capable of producing its minimum rated output. This is an evaluation of the rotor, stator and all diodes and their ability to produce current. While maximum atput depends on alternator temperature, the minimum acceptable output is used for reference. The charging system is also tested under partial load to determine if excessive voltage loss exists between the alternator and the battery through the circuit conductors.

(2) Start the engine-generator set, run the engine at approximately 750 RPM. If the test ammeter indicates less than 10 amperes charge, slowly apply the load across the battery until the ammeter indicates 10 amperes.

Let the engine run in this manner for 5 minutes to stabilize component temperatures within the alternator and its integral solid state regulator.

(3) Note voltage loss incurred by moving the positive voltmeter lead from the positive output terminal to the battery positive post, with the alternator producing 10 amperes.

If the loss exceeds 0.2 volts, check for poor connections or undersized conductors, repair as necessary.

(4) Increase set speed to rated speed (50, 60 or 400 Hz). Increase load on the battery causing the alternator to deliver its maximum current capacity of 35 amperes indicated on the test ammeter.

(5) Shut down the engine-generator set and disconnect the test equipment.

(1) Start the engine, allow a few minutes for warm up. Assure that the alternator drive sped is between 2000 to 3000 rpm. Indicated frequencies for 50, 60 or 400 Hz will provide the required battery charging alternator drive speeds for the respective engine-generator sets.

(2) Observe the test ammeter. A test ammeter reading in excess of 10 amperes is indicative of low batteries. If the test ammeter reading exceeds 10 amperes, remove the jumper from the 1/4 ohm 50 watt resistor thereby reducing alternator output current, by its insertion in the circuit.

(3) Observe the test voltmeter. The test voltmeter should indicate 28.0 Vdc ± .3 V at 75 degrees F.

(4) If the test voltmeter does not indicate the required voltage, use a small screw driver to adjust the rheostat on the voltage regulator to raise or lower the charging voltage.

(1) The voltage protector test configuration is that which occurs when the rear cover of the battery charging alternator is removed from the alternator housing, with the additional connection of the test voltmeter according to polarity, to the positive and negative output terminals.

(2) Start the engine-generator set, adjust the throttle to obtain rated speed, run a few minutes to normalize temperature of the charging system, note the charging voltage.

(3) Remove one cable from, one battery post, and note the charging voltage.

(4) If the charging voltage without the battery in the circuit exceeds 31.0 volts, the voltage protector is defective and must be replaced.

(5) Shut down the engine-generator set. Dis-

14-2

Figure 14-1. Voltage Regulator and Alternator Test

1 4 - 3

connect the test voltmeter, replace the 40 amplere fuse and reassemble the rear plate to the housing with 3 self tapping screws.

14-10. Disassembly, Cleaning and Inspection.

a. Disassembly. See figure 14-2 and disassemble

the battery charging alternator as illustrated.

b. Cleaning. Blow out all dirt from inside and wipe interior and exterior surfaces with a clean dry cloth.

c. Inspection. Inspect all components of alternator assembly for heat damage, excessive wear, broken parts, and corrosion.

seizure.

(1) Inspect bearings for rough motion or

(2) Inspect housing for distortion or cracks.

d. Diodes. Inspect diodes. Perform following check with multimeter.

(1) With multimeter on RXl scale, check continuity in opposite direction. This check should show a resistance of less than 20 ohms in one direction and

OPEN CIRCUIT in the reverse direction.

(2) A high resistance or low resistance in both directions indicates a defective diode. Replace a defective diode.

e. R o t o r .

(1) Inspect rotor shaft for scoring and distortion.

(2) Test rotor for short circuits using a growler.

shall be

(3) Check rotor resistance. Resistance value

11 to 14 ohms.

Field Assembly

(1) Inspect field assembly case for cracks or distortion.

(2) Inspect for openings in insulating materials.

(3) Check resistance with ohmmeter.

Resistance value shall be approximately one ohm.

(4) Minimum insulation resistance (one terminal to ground) shall be one megohm.

g. Voltage Regulator

(1) Inspect voltage regulator for cracks, broken leads or other physical damage.

(2) Perform the following tests for the voltage

regulator. See figure 14-3.

(a) Connect the positive lead of an ohmmeter to the yellow lead of the voltage regulator and check resistance to the red lead of the voltage regulator. The correct resistance is 600 to 900 ohms.

(b) Connect the positive lead of an ohmmeter to the red lead of the voltage regulator and check resistance to the yellow lead of the voltage regulator.

The resistance should infinite. Replace voltage regulator if it fails inspection and/or tests.

h. BrushAssembly.

(1) Inspect for excessive wear, broken leads, dirt and electrical requirements.

(2) Check brush spring tension. Tension should be 4 to 6 ounces to move brush against spring.

(3) Check assembly for excessive wear.

Replace if 3/16 or less extends beyond bottom.

(4) Insulation test, point E to A, B, C, D, no circuit, indicate no short circuit, assembly correct. See

figure 14-4.

(5) Continuity test, point A to B and C to D, continuous circuit indicates no open circuit, assembly

correct. See figure 14-4.

14-11 Repair.

a. Diodes. Discard and replace defective diodes.

b. Rotor.

(1) Smooth minor scratches, burrs, and dents on shaft with fine mill file.

(2) If shaft is bent or rotor is beyond repair, replace defective battery charging alternator rotor.

c. FieldAssembly.

varnish.

(1) Repair insulation damage with air-dry

(2) Smooth minor scratches, burrs, and dents on machined surfaces of case with fine mill file.

(3) If field assembly is beyond repair, replace defective battery charging alternator field assembly.

14-12. Reassembly, Test and Installation.

a. Reassembly. See figure 14–2 and reassemble

battery charging alternator except for cover assembly.

NOTE

After installation of pulley nut, see figure 14-2,

torque nut (item 33) to 40–50 foot pounds.

b. Tests See figure 14–3 and perform the

following tests:

(1) Remove black leads from negative terminal.

(2) Set ohmmeter to RX1 scale. Connect positive lead to regulator positive stud.

(3) Connect negative ohtnmeter lead to negative stud.

(4) Ohmmeter should indicate 30 to 40 ohms.

(5) Reverse ohmmeter leads. Ohmmeter should read infinity.

(6) Re–install cover assembly.

c. Installation

Refer to the Operator and Organ– izational Maintenance Manual and install the battery charging alternator.

14-4 Change 11

Figure 14-2. Alternator Assembly

35.

36.

37.

38.

39.

40.

41.

42.

43.

23.

24.

25.

26.

27.

20.

29.

30.

31.

32.

33.

34.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

10.

Screw

Nut

Circuit protector

Fuse

Fuseholder

Cover assy

Screw

Housing

Nut

Washer

Sleeve

Diode assy

Screw

Regulator

Electrical lead

Screw

Cover

Brush assy

Washer

Bolt

Nut

Housing

Sleeve

Washer

Diode assy

Sleeve

Washer

Diode assy

Stator

Nut

Washer

Pulley

Fan

Woodruff key

Spacer

Retainer

Bearing

Housing

Bearing

Rotor assy

14-5

M E 6 1 1 5 - 5 4 5 - 3 4 / 1 4 - 3

Figure 14-3. Regulator Excitation Test Circuit

M E 6 1 1 5 - 5 4 5 - 3 4 / 1 4 - 4

Figure 14-4. Two Terminal Brush Assembly

Section III. HYDRALIC PUMP ASSEMBLY

(CLASS 1, PRECISE SETS ONLY)

14-13. General.

The hydraulic pump assembly supplies oil under pressure to the electro-hydraulic actuator on Class generator sets.

The hydraulic pump is located on the left side of the engine at the rear of the timing gear housing and is driven by the hydraulic pump drive assembly.

The drive assembly is driven by the camshaft gear and contains two tapered roller bearings which are lubricated by engine oil splashed by other gears in the timing gear train. The pump assembly is lubricated by circulating hydraulic oil.

14-14. Hydraulic Pump Malfunctions, Removal and

Disassembly.

a. Symptoms and Isolation of Malfunction. A malfunction of the hydraulic sump is usually indicated by fluctuating frequency observed on the frequency meter as a result of erratic hydraulic oil pressure, sluggish response of the actuator to load changes as a result of low hydraulic oil pressure, or failure of the governor system due to loss of hydraulic oil pressure. To isolate a malfunction of the hydraulic oil pump, proceed as follows:

(1) Check hydraulic oil level by observing sight glass on hydraulic oil sump. Insure that oil level is sufficient.

(2) Check all hydraulic lines and fittings for signs of leakage.

(3) Carefully examine pump and mounting adapter for signs of leakage.

(4) Thoroughly clean area around fitting on pump for hydraulic line to filter and around drain valve on hydraulic pump.

(5)

Remove drain valve and drain hydraulic oil.

(6) hydraulic

Insert 0-400 psi gauge between pump and line to throttle actuator.

(7) Refill sump and start engine.

(8)

Pressure should be 310 to 330 psi. If the reading shows erratic pressure or low pressure, then there is a malfunction of the hydraulic pump assembly. Proceed to the removal, disassembly and repair procedures.

b. Removal and Disassembly.

(1) Open left hand area engine door, drain hydraulic oil pump and discard oil. Thoroughly clean area around hydraulic oil fittings. Disconnect lines from hydraulic pump.

Remove pump as illustrated

in figure 14-5. Cap all hydraulic fittings when

opened.

14-6

1. Nut

2. Washer

3. Nut

4. Washer

5. Screw

6. Screw

7. Washer

8. Screw

9. Washer

10. Hydraulic pump

11. Cap

12. Washer

13. Gasket

14. Drive assy

15. Packing

16. Screw

17. Washer

18. Gear

19. Shaft

20. Bearing

21. Spacer

22. Bearing

23. Spacer

24. Bearing race

25. Bearing race

26. Housing

27. Nut

28. Washer

29. Nut

30. Washer

31. Screw

32. Plate

33. Gasket

34. Adjustment Control Screw

ME 6115-545-34/14-5

Figure 14-5. Hydraulic Pump and Related Parts

14-7

(2) Secure the drive gear in a vise with protective copper jaws.

Remove capscrew and washer securing gear to shaft.

The fit of the gear to the shaft is 0.0017 to 0.0002 inch loose. Remove gear from shaft. If necessary, use gear puller.

(3) The clearance of the bearing assembly on the shaft is 0.0000 inch to 0.0013 inch interference fit and the clearance of the bearing in the housing is

0.000 to 0.002 inch interference fit.

The bearing outer diameter is 1.980 to 1.981 inches.

(4) Place drive assembly in a press with the hydraulic pump mounting side down and drive shaft from the housing,

NOTE

When removing the shaft from the housing, one cone will remain on the shaft and the other will fall out. The bearing races will remain in the housing.

(5) Remove front bearing cone and cone spacer from housing.

NOTE

Do not intermix front and rear bearing cones and races if bearings are to be reused.

(6) If the bearings require replacement, press rear bearing cone from shaft.

(7) Using a puller, remove front bearing race from housing.

Remove bearing race separator from its groove in the housing.

Remove rear bearing race from housing.

14-15. Cleaning, Inspection, and Repair.

a. Wash all parts in cleaning solvent, Federal

Specification P-D-680.

b. Inspect hydraulic pump drive gear and replace if gear is worn, scored, chipped, or has broken teeth.

c. Replace bearings if races or rollers are worn, pitted, or scored.

Bearings must be replaced when rebuilding pump.

NOTE

The tapered bearings must be replaced as an assembly.

The assembly consists of the bearing cones, cone spacer, races and race spacer. The spacers are factory selected to give the proper end clearance.

d. Replace all defective parts as required. Bearinga, O-rings, and gaskets must be replaced during overhaul.

14-16. Reassembly, Installation, and Adjustment.

a. Place drive assembly in a press with the hydraulic pump mounting side down and press rear bearing race into housing so that it is approximately

1/4 inch below the mounting surface.

b. Position bearing race spacer in housing next to the rear race.

Slowly press both the spacer and bearing race into the housing until the spacer snaps into place.

c. Press the front bearing race in the housing until it contacts the race spacer.

d. Press the rear bearing cone onto the shaft until it contacts the shoulder.

e. Install the shaft into the housing from the hydraulic pump side.

f. Position the cone spacer on the shaft.

g. Press the front bearing cone onto the shaft.

h. Install gear on shaft with washer and capscrew.

i. Lubricate bearings with engine oil. Tighten capscrew to 95-105 foot-pounds. Strike both ends of the shaft with a soft-headed hammer. Again tighten the capscrew to 95-105 foot-pounds. Shaft and bearings should turn freely when spun by hand.

k. Install hydraulic oil pump on hydraulic pump adapter with three screws and lock washer.

l. Use a new 0-ring and install the hydraulic pump adapter and drive assembly and pump to the front support plate with lock washer, nuts and bolts; tighten the nuts securely.

m. Connect oil return line to pump.

NOTE

To facilitate assembly and prevent galling, coat all mating and bore surfaces of bearing with clean engine oil, or other suitable lubricant.

n. Connect a 0-400 PSI gauge with tee to the output of the hydraulic pump.

o. Connect hydraulic oil line between filter and pressure gauge.

14-8

p. Fill hydraulic system with hydraulic oil MIL-

H-5606.

q. Start the engine. (Refer to Operator and

Organizational Maintenance Manual).

Remove the hex cap (11, fig. 14-5) and washer

(12) located on top of the pump housing, and adjust the slotted adjustment control screw (34) to obtain a pressure of 320 ± 10 psi.

s. Replace hex cap, shut down engine, drain hy– draulic system, remove pressure gauge, connect hydraulic output line to pump, and refill system with hydraulic oil, MIL-H-5606.

Section IV. SPEED SWITCH, TACHOMETER DRIVE AND ADAPTER

14-17. General.

a. The speed switch, driven by the camshaft through a tachometer drive assembly and an angle adapter, provides sequenced control of circuits during engine startup and protection against engine overspeed during operation. Three sets of contact elements, S9–1,

S9-2, and S9–3, contained in the speed switch, are set to open, close, or transfer by centrifugal force at certain engine speeds. The speed switch drive gear is designed to drive the speed switch at one–half engine speed b. At an engine speed of 580 to 620 rpm (accelerating) element S9–1 transfers two sets of contacts, energizing the field flash circuit and de-energizing the crank relay to stop the starting motor.

On Class 1 sets, when the engine reaches the speed range of 1180 to 1220 rpm (Mode I); 1650 to 1700 rpm (Mode H) element S9–2 closes, energizing the electro-hydraulic governor which takes over control of engine speed.

d. Speed switch element S9-3 consists of two sets of contacts which are set to transfer at an engine speed of 2425 ± 25 rpm to shut down the engine and prevent damage to the equipment. Shutdown is achieved by de-energizing the stop-run relay and the fuel solenoid, cutting off fuel to the engine.

Elements S9–1 and S9–2 reset at 100 rpm (decreasing) below actuation speed. Element S9–3 is manually reset by a pushbutton on the speed switch housing.

14–18. Speed Switch Removal.

Refer to Operator and Organizational Maintenance

Manual for removal of the speed switch.

14-19. Speed Switch Tests, Adjustment, Repair and

Installation.

a. Connect a variable speed drive device to the speed switch drive. The drive device must have a tachometer in order to determine the speed of the device in rpm’s.

b. With an ohmmeter on the R1 scale, reading from the speed switch connector, check for the contact conditions of elements S9–1, S9-2, and S9-3 illustrated

in figure 14-6.

c. When contact conditions are verified, as shown

in figure 14-6, start variable drive and gradually

increase speed, with ohmmeter connected to pins B and

A. At a speed of 300 ± 15 rpm, the ohmmeter should indicate that contact A–B opens. Hold the variable speed drive at that speed and transfer the ohmmeter leads to pins A and C. The ohmmeter should indicate a closed contact.

d. Leave the ohmmeter leads connected to pins A and C and gradually reduce speed. In the range of 190 to 210 rpm, the contacts of element S9–1 should reset to

the condition illustrated in figure 14–6. To verify

operation of element S9-1 contacts A and C, increase drive speed gradually and observe that the contacts close at 300 ± 15 rpm range.

e. Connect ohmmeter leads across pins D and E and verify an open circuit. Increase drive speed and observe that element S9–2 (contacts D and E) closes in the speed range of 600 ± 20 rpm (Mode I); 840 ± 20 rpm

(Mode II). Gradually reduce speed to 490 minimum rpm

(Mode I); 725 minimum rpm (Mode II). Observe that

element S9–2 resets to the condition shown in figure

14-6.

NOTE

(Required for P/N 70-1105-3 and P/N 70-

1105-4 switches only) In order to bench check the trip speeds, apply +24VDC to terminals E and G of the MS3102R–18-1P connector with the case negative.

f. Connect ohmmeter across pins H and G and verify a closed circuit. Increase drive speed gradually.

The contacts should open at a speed of 1200 to 1250 rpm. Hold drive speed and read contacts F and J.

Meter should indicate a closed circuit. Reduce drive speed to less than 1000 rpm, press the manual reset switch and observe with the meter that element S9–3

contacts reset to the condition shown in figure 14–6.

g. To obtain the required performance character– istics during tests c through f adjustments can be made.

By loosening screws (1, figure 14-7) and rotating the

cap and cover assembly relative to the body assembly, the trip points of all three elements can be raised or lowered. In addition, the trip speed of each individual element can be raised or lowered by removing cover

screws as shown in figure 14-6 and turning appropriate

set screw located beneath cover screws with a 1/16 inch allen wrench.

Change 11 14-9

Figure 14-6. Speed Switch Sensitivity Tests.

NOTE

No adjustments required for Speed Switch

Forester (figure 14-7A) used on Serial Num–

hers FZ–01299 on, for 50/60 Hz and Serial

Numbers FZ-06399 on, for 400 Hz. Speed setting can be checked, but not adjusted.

14–20. Speed Switch Disassembly.

14-21. Tachometer Drive and Adapter Removal and

Disassembly.

See figure 14-6 and proceed as follows:

a. Adapter. Uncouple adapter from tachometer drive.

Refer to figure 14-7; cut safety wire and disassemble in

sequence of index numbers observing the following: g. If either the rotor assembly, the body assembly or the spacer are damaged or defective, replace defective part. Reassembly is the reverse order of disassembly.

Refasten with lockwire after readjustment.

b. Tachometer drive. Remove screw and clamp.

Lift tachometer drive up and out of engine housing.

c. Disassemble tachometer drive:

(1) By means of a gear puller, remove gear from shaft.

b. Repeat the test and adjustment procedures in

paragraph 14–19.

Refer to Operator and Organizational

Maintenance Manual and install speed switch.

(2) Remove shaft from top of housing.

(3) Remove preformed packing.

14-22. Tachometer Drive and Adapter Inspection and

Repair.

14-10 Change 11

1. Screw

2. Washer

3. Rotor assembly

4. Counterweight

5. Spacer

10.

11.

Packing

Body assembly

Retaining ring

Cap and cover assembly

Screw

Plate

6115-545-34/14-7

Figure 14-7. Speed Switch

Change 8 14-10A/(14-10 blank)

1. Screw

2. Lock Washer

3. Base Assembly

4. Rotor Cap

5. Cotter Pin

6. Rotor

7. Retaining Ring

8. Retaining Ring

9. Bearing

10. Keyed Shaft

11. Base

12. Label

13. Electronics Assembly

Figure 14-7A. Speed Switch

Change 3 14-11

ME 6115-545-34/14-8 C1

Figure 14-8. Tachometer Drive

Inspect all parts for signs of chipping, cracking, and/or excessive wear. Replace as required.

14-23. Tachometer Drive and Adapter Reassembly and Installation.

See figure 14-8 and proceed as follows:

a. Reassemble shaft, retaining ring, retaining bushing, bushing and housing as shown.

b. Reassemble bushing and thrust washer by means of a small press. Refit gear to shaft.

c. Coat housing and preformed packing with film of light engine oil. Refit preformed packing.

d. Hold tachometer drive vertical and insert down into engine.

e. Install clamp (tightening action of screw will seal tachometer drive in engine).

f. Refer to Operator and Organizational Maintenance Manual and install speed switch.

14-12 Change 1

14-24. General.

Section V. ELECTRIC STARTER c. Remove four brush springs (21) by lifting end of spring from slot and sliding spring from mounting arm. Remove four brushes (22) from brush plate (18).

The engine generator set is equipped with a 24-volt shift lever type electric starter. It is mounted directly to the flywheel housing at the engine’s right rear and is connected to the batteries by a solenoid switch. It rotates clockwise as viewed from the drive end. Battery voltage is supplied to energize the starter solenoid which energizes the electric starter to crank the engine.

(1) Tag and disconnect electrical leads from brushes (22) by removing screw (19) and washer (20).

(2) Measure the length of each brush. If any brush is less than 3/8 inch long, replace the complete set of brushes with new brushes.

d. Install the brushes as follows:

14-25. Starter Replacement.

a. See figure 14-9 and proceed as follows. Remove starting motor. Refer to Operator and Organizational

Maintenance Manual as follows.

(1) Disconnect the negative cable from the battery.

(2) Tag and disconnect battery cables and electrical wires from starter (3, fig. 14-9).

(3) Remove tool box to gain access to starter screws (1).

(1) Clean all brushes with a clean, dry cloth only.

Do not permit dry cleaning solvent to come in contact with the brushes.

(2) Install brushes in reverse order of removal.

e. See figure 14-10 and install the commutator

end head (11) in reverse order of removal.

14-27. Starter Solenoid.

To replace the starter solenoid (29, fig. 14-10) proceed as

follows:

(4) Remove three 12-point screws (1) and three washers (2). Remove starter (3) and starter adapter (4).

NOTE a. Removal.

Check ring gear to assure that teeth are not damaged.

b. Installation.

Install the starter (3, fig. 14-9) on the flywheel housing in reverse order of removal.

(1) Disconnect electrical connections to solenoid.

(2) Remove screws (26, fig. 14-10).

(3) Remove plug (23) and gasket (24).

(4) Slide solenoid (29) toward brush end of motor.

14-26. Brushes Inspection and Replacement.

(5) Slip back rubber boot and insert screwdriver in slot of solenoid core to prevent core from rotating while removing nut (25).

ceed as follows: a. Gain access to the starter motor as in

paragraph 14-25.

b. Remove the starter commutator end head

assembly, (11) (fig, 14-10) as follows:

(6) Remove solenoid (29).

b. Installation.

(1) Scribe a mark on end head (11) and frame to locate relative position at assembly.

(2) Remove lead assembly (3, fig. 14-10) by mov-

ing nut (l), washer (2) and nut (4), lockwasher (5), flat washer (6), phenolic washer (7), flat washer (8), and rubber washer (9).

(3) Remove seven bolts (10).

(4) Remove commutator end head assembly (11), gasket (12), and washer (13).

(1) Install starter solenoid in reverse order of removal and perform steps (2) and (3) below.

(2) Place starter on bench and apply 24 vdc to the starter solenoid terminals.

(3) With 24 vdc applied to starter solenoid terminals, the starter drive pinion should be observed moving forward and spinning.

c. Disassemble Disassemble as illustrated in

figures 14-11 through 14-13.

(1) Refer to figure 14-11 and disassemble major

subassemblies as follows:

(15).

(5) Remove insulator (14) and insulating bushing

A l l d a t a o n p a g e 1 4 - 1 4 , i n c l u d i n g F i g u r e 1 4 - 9 , i s d e l e t e d .

Change 10

14-13

14-15

Figure 14-10.

Electrical Starter Brush and Solenoid Assembly

14-16 Change 4

1. Screw

Plug

2. Housing assy 7. Wick

3. Bearing

4. Seal

5. Plug

Screw

Washer

10. Packing

11. Screw

12. Washer

13. Pin

14. Cover

15. Gasket

16. Washer

17. Drive

18. Yoke assy

19. Screw

20, Screw

21. Housing

22. Packing

23. Packing

24. Bearing

25. Washer

26.

Washer

26A. Thrust washer

26B. Thrust washer

27.

Armature

28.

Insulator

29.

Frame-field assy

ME 6115-545-34/14-11 C4

Figure 14-11.

Electric Starter Assembly

1. Screw

2. Washer

3. Plate assy

4. Nut

5. Washer

6. Washer

7. Washer

8. Washer

9. Washer

10. Screw

11. Screw

12. Screw

13. Screw

14. Coil

15. Coil

16. Washer

17. Bushing

18. Screw

19. Plate

20. Housing

ME 6115-545-34/14-12

Figure 14-12.

Frame and Field Assembly

14-17

14-18

Nut

2. Lockwasher

3. Nut

4 W a s h e r

5. Washer

6. Bushing

7. Nut

8. Cover

9. Bushing

10. Insulator

11. Stud

12. Screw

13. Washer

14. Lug

15. Cover & Contact Assy

16. Gasket

17. Nut

18. Washer

19. Contact

20. Spring

21. Washer

22. Retainer

23. Ring

24. Retainer

25. Spring

26. Retainer

27. Boot

28. Washer

29. Core a

S S y

30. Pin

31. Shaft

32. Core

33. Case

ME 6115-545-34/14-13

Figure 14-13. Solenoid Assembly

(a) Remove item 1 through 12 as shown on

figure 14-11.

(b) Lift packing (23) and knock out pin (13).

Remove cover (14).

(2) Disassemble frame and field coil assembly

as illustrated in figure 14-12.

(3) Disassemble solenoid assembly as illustra-

ted in figure 14-13.

14-28. Cleaning and Inspection.

a. Cleaning.

(1) Blow out all dirt from inside field frame and wipe interior with a clean cloth.

CAUTION

Do not submerge armature, field coils, solenoid or clutch drive in solvent.

(2) Clean field coils and frame thoroughly with a cloth dampened with cleaning solvent Federal

Specification P-D-680.

Be careful not to damage protective insulation and fungus coating. Dry thoroughly with compressed air.

(3) Remove loose particles from armature with compressed air and wipe with a clean cloth dampened with cleaning solvent.

Clean commutator lightly with No. 00 sandpaper and remove all traces of dust with low-pressure compressed air.

(4) Clean brush holders and springs with a brush and cleaning solvent, Federal Specification

P-D-680, and dry them thoroughly with compressed air. Clean insulation and plate with a clean cloth dampened with cleaning solvent and dry with compressed air.

(5) Clean solenoid relay assembly parts with a clean cloth dampened with cleaning solvent, Federal

Specification P-D-680, and dry with low-pressure compressed air.

(6) Clean brushes with a clean, dry cloth only.

Do not permit cleaning solvent to come in contact with the brushes.

b. Inspection and Tests.

(1) Inspect drive assembly drive pinion for broken, chipped, or badly worn teeth. Replace drive assembly if defective.

(2) Inspect internal splines in drive assembly shell and pinion for cracked, chipped, or broken condition.

Replace drive assembly if defective.

(3) Inspect all drive assembly splines and pinon teeth for nicks and burrs.

(4) Test field coils for insulation breakdown with megger connected between frame and one coil terminal. Minimum resistance reading permissible is one megohm.

Replace starter assembly if coil is defective.

(5) Inspect coil terminal lugs for damaged threads.

(6) Test armature for grounds with a test light.

Touch a test light probe to the armature core and the other probe to a commutator bar riser. If test light glows, armature is grounded. Repeat test for all commutator bars.

(7) Test armature for short circuits using a growler.

(8) Check brushes for excessive wear.

14-29. Repair.

a. Pinion Housing and Commutator End Head.

(1) Smooth minor scratches, burrs, and dents on machined surfaces using a fine mill file.

(2) Repair damaged threads.

(3) Smooth minor rough spots, score marks, and scratches from inside bore of bronze bearing using a fine stone or crocus cloth dipped in cleaning solvent, Federal Specification P-D-680.

b. Brush Holder Assembly. Replace a defective brush holder assembly.

(1) Resurface commutator removing no more than 0.005 inch during any one cut and no more than

0.002 inch on final cut. Check that final diameter of commutator is not less than 1.6470 inches.

(2) If commutator diameter is satisfactory, undercut mica to a depth of 0.025 to 0.032 inch below commutator surface.

NOTE

Use care in undercutting. D

O not widen commutator slots by removing metal from segments, and do not leave thin edge of mica next to segment.

(3) After the mica has been undercut, remove all copper and mica particles with compressed air.

Polish the commutator in a lathe with number 2/0 sandpaper while the armature is rotating at 1500 rpm. After polishing the armature, check that commutator diameter is not less than 1.6470 inches.

Replace if diameter is less.

14-19

d. Drive Assembly.

(1) Smooth burrs, nicks and rough spots on splines and pinion teeth using a fine stone or crocus cloth dipped in cleaning solvent, Federal Specification

P-D-680.

(2) Smooth rough spots, scoring, scratches and nicks on inside bore of sleeve bearings and all surfaces of bronze bearings using crocus cloth dipped in cleaning solvent, Federal Specification P-D-680.

e. Solenoid Assembly Repair.

(1) Check relay windings for shorts or grounds with ohmmeter.

Replace relay if windings are defective.

(2) Replace relay if contact assembly shows defects such as warpage, cracks, or broken springs.

(3) Minor burns or pits on contact surfaces are permissible.

If conditions are severe, replace relay. Do not use a file to dress severely burned or pitted contact surfaces.

f. Field Coil Assembly.

(1) Smooth minor scratches, burrs, and nicks on machined surfaces of frame using fine mill file,

(2) Repair damaged threads in frame. Repair damaged threads on field coil terminal stud.

(3) Replace starter assembly if field coil insulation resistance is less than one megohm.

14-30. Reassembly and Adjustments.

Reassembly.

Reassemble electric starter in

reverse order of disassembly. See figures 14-11

through 14-13.

b. Adjustments.

Perform the following adjustments during reassembly.

(1) Solenoid relay plunger shaft.

(a) See figure 14-14. Connect 12 Vdc

across relay terminals A and B. Using a jumper, momentarily connect lead terminal C to terminal A to pull the relay plunger into the sealed position. Place a straight edge across the relay case as shown.

Measure the distance from the shaft shoulder to the straight edge.

This dimension should be 7/32 inch maximum for proper assembly, and the self-locking nut will be tight after assembly. Disconnect power from terminals A and B.

(b) If the shoulder to straight edge dimension exceeds 7/32-inch, the self-locking nut must be installed and tightened until the end of the nut and the end of the shaft are flush as illustrated in figure 14-

14. This procedure will provide adequate overtravel.

(2) Drive assembly pinion clearance.

(a) See figure 14-15 for adjustments.

(b) Remove motor field coil connector from the motor switch terminal stud.

(d) Remove solenoid relay lead assembly connecting battery switch terminal stud and battery solenoid relay terminal.

(e) Connect a 24-volt battery supply to battery solenoid relay terminal and motor solenoid relay terminal.

(f) Momentarily hold a jumper lead from the motor switch terminal stud to the motor solenoid relay terminal.

The pinion will now shift into cranking position and remain so until the battery is disconnected.

(g) Push pinion back toward armature to take up slack movement.

(h) Check for 0.020- to 0. 050-inch clearance between thrust washer and pinion. To adjust, remove inspection plug and gasket. Adjust clearance to 0. 020 to 0. 050 inch by turning shaft nut as

shown in figure 14-15.

(i) Connect a test light or other continuity checker between the battery switch terminal and motor switch terminal stud.

(j) Connect one of the posts of a 24-volt battery to the battery solenoid relay terminal.

Connect the other battery post to the motor solenoid relay terminal.

(k) Place a 0. 983-inch spacer block

(figure 14-15) between the pinion and thrust washer

and momentarily hold a jumper lead from the motor switch terminal stud to the motor solenoid relay terminal.

The pinion will now shift against the spacer block and remain so until the jumper lead is disconnected. The motor must not run. The motor must run when the distance between the pinion and thrust washers is 0. 500 inch.

(1) An open circuit should be indicated between the battery switch and motor switch terminals.

If continuity exists, decrease the pinion clearance

((a) above) to the minimum limit of 0.020 inch and recheck to make sure an open circuit now exists.

(m) Disconnect battery and test equipment and install motor field connector, ground lead and solenoid relay lead.

(n) Install inspection plug and gasket,

14-31. Test and Installation.

14-20

Figure 14-14.

Solenoid Adjustments

a. See figure 14-16 and connect the electric

starter in the no-load test circuit illustrated. Perform no-load test as follows:

(1) Energize the test circuit and obtain a voltage of 22 volts by varying the variable resistance.

(2) Check the speed of the armature on the tachometer.

Minimum speed should be 7000 rpm.

(3) Check the current draw on the ammeter.

Maximum current draw should be 90 amperes. If a low-speed, high-current condition exists, possible causes are excessive armature arcing, armature ground, armature short, or armature drag caused by loose pole shoes or faulty bearings. A low-speed, low-current condition indicates faulty brushes or faulty connection.

b. See figure 14-16 and setup for lock torque

ted as illustrated.

CAUTION

Never operate the electric starter with all resistance removed from the circuit. Failure to adhere to this caution will result in extreme motor speeds which can cause damage to the motor and possible injury to personnel.

The variable resistance should be one with a high current capacity.

(1) Energize the circuit and check the scale to determine the torque output of the motor.

(2) Scale should indicate 22 pound-feet (minimum), at 400 amperes and approximately four volts, as indicated on the meters.

. Installation. Install the starter motor on the flywheel housing using the disassembly steps in reverse order. See figure 14-9.

14-21

14-22

Figure 14-15. Drive Assembly Pinion, Clearance Adjustments

14-23

Figure 14-16. Electric Starter, Test Circuits

14-32. General.

Section VI.

LUBE OIL COOLER AND FILTER BYPASS VALVE faulty, the oil cooler must be replaced. If the shell is damaged it must be replaced.

The lube oil cooler is mounted on the right side of the engine cylinder block and receives coolant from the water pump.

Engine lubricating oil is pumped through a chamber in the lube oil cooler. The chamber walls are cooled by the coolant and, in turn, maintain the engine lube oil at a safe operating temperature.

b. Reassembly.

(1) See figure 14-17 and reassemble the lube

oil cooler.

14-33. Removal, Disassembly, and Cleaning of Oil

Cooler.

(2) After reassembly, place the lube oil cooler on a surface plate as if it were being mounted. Using a feeler gauge, check to see if all machined surfaces contact the plate within 0. 005 inch. Loosen and retighten screws to obtain this clearance.

a. Removal. Refer to the Operator and Organizational Maintenance Manual for removal procedures.

c. Installation. Refer to the Operator and Organizational Maintenance Manual.

b. Disassembly.

See figure 14-17 and disassem-

ble the lube oil cooler as shown.

14-36. Lube Oil Filter Bypass Valve.

c. Cleaning.

ing-solvent, Federal Specification P-D-680.

14-34. Inspection and Repair.

a. Inspection.

(1) Inspect cooler housing, bonnet, and header for cracks, distortion, and scoring of mating surfaces.

(2) Inspect cooler assembly passages for obstructions.

Clean all metallic park with cleanb. Repair.

(1) Clean passages with steam under to insure that there are no obstructions.

pressure

(2) Smooth burrs or scoring on mating surfaces with a fine mill file.

(3) Replace any parts damaged beyond repair.

(4) Discard all gaskets and preformed packing.

14-35. Test, Reassembly, and Installation.

a. General.

The lube oil filter bypass valve is part of the header block of the engine lube oil filter assembly. If the filters become clogged, such that the differential pressure across the combination of both filters rises to 45 psi the bypass valve opens permitting unfiltered oil to bypass the filters and go directly to the main oil gallery.

Cold weather induced thickening of the oil will cause the filters to be bypassed. As the engine oil warms the by-pass valve will close inserting the filter elements into the oil stream.

b. Removal.

(See figure 14-18)

(1) Both oil filters must be removed. Refer to

Operator and Organization Maintenance Manual.

(2) Remove the oil filter header block by removing six cap screws.

(3) Thoroughly clean the area at the rear of the header block where the bypass valve is located.

a. Test.

(1) Make up two plates, one with a drilled and tapped hole to accept an air hose fitting, and secure them with C clamps to cover the oil inlet and outlet openings in the side of the oil cooler.

Use the preformed packing to seal the plates.

(4) Remove the cap, gasket, spring, piston sleeve and seat.

c. Cleaning and Inspection.

Wash valve parts in cleaning solvent. Inspect carefully for wear or damage. Replace any worn or damaged parts.

d. Installation.

(2) Attach an air hose to the drilled and tapped plate; submerge the oil cooler in hot water until the oil cooler temperature is up to approximately

Test for leaks with air pressure of 100 psi.

150°F.

(3) No air bubbles shall appear at either end of the lube oil cooler.

If the cooling core open is bly.

(1) Install valve

(2) Renew filter bypass valve gasket.

in reverse order of disassemheader gaskets and lube oil

14-24

1. Screw

2. Washer

3. Header

4. Gasket

5. Screw

6. Washer

7. Bonnet

8. Gasket

9. Cooler

ME 6115-545-34/14-17

Figure 14-17.

Lube Oil Cooler

14-25

(3) Mount filter header to oil gallery with 6 cap screws.

(4) Mount engine lube oil filter to filter header.

Refer to Operator and Organizational

Maintenance Manual.

e. Test.

(1) Start engine.

Refer to Operator and Organizational Maintenance Manual.

(2) Observe the oil pressure gauge located in the control cubicle.

(3) If the oil pressure is abnormally high or low after the engine has warmed, then a failure in the relief valve has occurred.

14-26

10,

Screw

Washer

Header assembly

Cap

Gasket

Spring

Piston

Sleeve

Seat

Gasket

Figure 14-18.

Lube Oil Bypass Valve

ME 6115-545-34/14-18

Section VII. NOZZLE HOLDER ASSEMBLIES

14-37. General.

a. Each engine cylinder is provided with a multihole, differential needle, hydraulically lifted, nozzle holder assembly.

The function of each nozzle holder assembly is to direct a metered quantity of fuel received from the fuel injection pump into the corresponding engine combustion chamber in a highly atomized, pre-determined spray pattern in such reamer as to produce the most efficient performance. Each nozzle holder assembly consists of two assemblies, an injection nozzle holder and an injection nozzle.

b. The holder assembly positions the nozzle in the cylinder head and provides a means of conducting fuel received from the fuel injection pump to the nozzle. The holder consists of a steel holder body, two locating dowels, spindle, spindle spring, pressure adjusting screw, adjusting screw locknut, gaskets, cap nut, and a nozzle retaining nut.

c. The nozzle assembly consists of a nozzle valve and–a nozzle body in which are located four spray orifices equally spaced 90 degrees apart. The nozzle valve is operated hydraulically within the valve body by fuel delivered under pressure by the fuel injection pump.

The nozzle is positioned on the holder by two dowels whereby the four spray orifices are fixed on a plane parallel to the piston top, and the nozzle fuel duct is registered with the holder fuel duct .

d. Fuel enters the nozzle holder fuel inlet passage, passes through the holder fuel duct into the nozzle fuel duct via an annular groove in the nozzle body, and then into the pressure chamber above the nozzle valve seat.

At the instant the fuel pressure in the pressure chamber exceeds pressure exerted on spindle and nozzle valve by the spindle spring, the nozzle valve is lifted off its seat (popped) and fuel is forced through orifices in the valve body end and into the corresponding engine combustion chamber. The nozzle valve is returned to its seat by pressure exerted by the spindle spring when the fuel injection pump has ceased to deliver fuel to the nozzle holder.

14-38, Removal.

Refer to the Operator

Manual to remove the and Organizational Maintenance nozzle holder assembly.

14-39. Disassembly, Cleaning and Repair.

NOTE

When more than one nozzle holder assembly is disassembled, keep parts of each separate. Complete disassembly of the nozzle holder assembly is seldom necessary. In most cases, only disassembly and cleaning of the nozzle valve body and valve is required to place the nozzle holder in good operational condition.

At completion of repair, check operation in accord-

ance with paragraph 14-40.

The nozzle valve and nozzle valve body are mated parts, and must be kept together. If replacement of either part is necessary, both parts must be replaced as matched sets. Remove, clean, and inspect the nozzle valve body and valve as follows: a. Clamp nozzle holder body in a suitable holding fixture.

b. Remove cap nut (10) and gasket (11) from upper end of nozzle holder (15). Loosen pressure adjusting screw locknut (8) and turn pressure adjusting screw

(9) out sufficiently to release spring tension on spindle

spring (12). See figure 14-19.

Using a suitable socket or box wrench, loosen and remove the nozzle retaining nut (5). Remove the nozzle valve body (3) and nozzle valve (4) from the retaining nut.

Start the nut back onto the holder body to protect the lapped end of the holder body

(15).

CAUTION

Do not allow the solution to get on the hands or body; use tweezers or the basket method to handle the parts.

plate

Withdraw the valve from the valve body and it in a carbon and rust remover solution for cleaning. Normally, the valve can easily be withdrawn from the valve body, however, in some cases it may be necessary to soak the valve body and valve in carbon removing compound Type 2 per Federal

Specifications P-C-111 before the valve can be withdrawn. For faster and better cleaning results, the carbon removing compound should be heated to approximately 200° F.

The parts generally can be separated in two or three minutes; however, if necessary they can be left in the solution longer.

After removing the parts from the solution, immediately place them in clean diesel fuel for neutralizing.

Always handle the parts carefully to protect the lapped surfaces.

The valve (4) and the seat in the valve body

(3) are originally ground to slightly different angles to provide a line contact seat between the two parts.

Practically all the wear occurs in the seat in the valve body.

The valve should never be lapped to the seat in the valve body.

Using a magnifying glass, inspect condition of seat in the valve body (3). If the seat is damaged or worn in any way to prevent proper seating of the valve, the nozzle assembly (1) must be replaced.

g. The outer surfaces of the valve body (15) may be cleaned with a brass wire brush. Do not scrape carbon from the surface around the orifices in tip of valve body with any hard object as damage may result. Clean the four orifices in the valve body tip

Change 1 14-27

with a cleaning wire and pin vise.

10.

11.

12.

13.

14.

15.

Nozzle assembly

Gasket

Nozzle body

Nozzle valve

Retaining nut

Dowel pin

Locknut

Pressure adjust screw

Cap nut

Gasket

Spindle spring

Spindle

Gasket

Holder body

Figure 14-19.

Nozzle Holder Assembly

ME 6115-545-34/14-19 C7 h. Visually inspect the condition of the valve (4), preferably with aid of a magnifying glass. The lapped surface (large outer diameter) of the valve must be smooth and free of signs of scoring. Also, the valve must not show any wear or damage at seat location.

If the valve is damaged in any way, the nozzle assembly (1) must be replaced.

i. Thoroughly rinse the valve (4) and valve body (3) in clean diesel fuel. The valve must fit freely in the valve body.

To check this fit, lift valve about one third of its length out of the body. The valve should slide down to its seat without aid when assembly is held at a 45° angle.

j. If the fit of the valve in the valve body is unsatisfactory, the valve may be cleaned and polished with lapping compound and castor oil used on tissue paper. The valve may be held by its stem in a revolving chuck for this cleaning operation. An orange stick or round toothpick will be helpful in cleaning the valve.

CAUTION

Hard or sharp tools, emery cloth, crocus cloth, jeweler’s rouge, grinding compounds, or other abrasives should never be used in cleaning.

14-28 Change 7

k. Thoroughly rinse the valve (4) in clean diesel fuel before installing it in the valve body (3).

l. Examine the flat sealing surface of the valve body (surface which contacts lower end of the holder body) and make certain surface is clean and free of scratches. This surface may be lapped, if necessary, using lapping compound, castor oil, and a lapping block.

After lapping, remove all traces of lapping compound with clean diesel fuel.

m. Make certain that the bottom flat seating surface of the nozzle holder body (15) is clean and in good condition. Rinse the valve (4) and valve body

(3) in clean diesel fuel, then insert valve (4) into position in the valve body (3). Place the valve body

(3) and valve (4) in position on the end of the nozzle holder body and center the valve body with the holder body (15). Install and tighten the nut (5) to a torque of 40 to 60 inch-pounds.

NOTE

It is important that the valve body be centered in the nozzle retaining nut.

Use care while tightening the nozzle retaining nut so that the valve body remains centered in the nut.

n. If malfunctioning of the nozzle holder assembly was not corrected by removal and cleaning of the nozzle valve body and valve, disassemble and clean the nozzle holder as follows:

(1) Clamp nozzle holder (15) assembly in a holding fixture and remove the cap nut (10) and gasket (11 ) from upper end of nozzle holder. Loosen and remove the pressure adjusting screw locknut (8).

(2) Remove pressure adjusting screw (9), spindle spring (12), and spindle (13).

(3) Remove nozzle retaining nut (5), and disassemble the nozzle assembly.

(4) Place all parts in clean diesel fuel. Using filtered compressed air, blow out the fuel passages in the holder body.

(5) Visually inspect the parts for damage or wear; replace necessary parts. Examine the flat sealing surface of holder body (15) (surface which contacts upper end of valve body) and make certain the surface is clean and free from scratches. This surface should be lapped if necessary, using lapping compound, castor oil, and a lapping block. When lapping, use care to keep the nozzle holder body square with the lapping block to assure contact with the entire area being resurfaced.

After lapping, remove all traces of the lapping compound with clean diesel fuel and dry with filtered compressed air.

(6) Examine the spindle spring (12). If the spring is scratched or pitted, it must be replaced.

Also, the spring must be replaced if the ends have worn. Always replace springs when rebuilding injector.

(7) Rinse spindle (13) in clean fuel and insert it into holder body (15). Place the spindle spring (12) in position on spindle (13). Install pressure adjusting screw (9), pressure adjusting screw locknut (8), cap nut (1 O) and gasket (11); do not tighten at this time.

(8) Install nozzle valve (4), valve body (3), and nozzle retaining nut (5). Tighten nut to a torque of

40 to 60 foot-pounds.

. When rebuilding an injector assembly, the nozzle assembly, spindle (13), spring (12), adjusting screw (9), and all gaskets (2, 14, 11) must be replaced.

14-40. Test and Adjustment.

WARNING

Keep hands away from nozzle tip when popping a nozzle.

The finely atomized fuel is ejected with sufficient force to penetrate the skin and cause blood poisoning.

a. Use diesel injector test set tool (table 2-1)

and lest and adjust each nozzle as follows

(1) Bolt or clamp base of nozzle tester to a work bench.

(2) Turn nozzle tester valve handle to the open position. Loosen filler cap to prevent air lock in the tester. Operate handle until fuel flows from end of tester fuel line, then close valve.

(3) Install nozzle in tester and connect line.

Place spray collector under valve end of nozzle.

(4) Open nozzle tester valve. Operate handle a few quick strokes and observe popping pressure indicated on pressure gauge. Popping pressure for the injectors is 2900 ± 75 psi.

NOT E

New nozzles and rebuilt nozzles with new springs are set at 3100 to 3150 psi to compensate for initial set of new spindle springs.

b. Adjust nozzle to obtain popping pressure as follows

(1) Remove cap nut (12) from upper end of nozzle and loosen adjusting screw locknut (9).

(2) While operating handle, turn pressure adjusting screw (8) into increase or out to decrease popping pressure. When pressure is obtained, hold adjusting screw and tighten locknut to 60 to 75 footpounds torque.

c. Dry the nozzle tip. Operate handle slowly until pressure is approximately 200 psi below popping

Change 1 14-29

pressure.

Observe nozzle tip for fuel leakage. If nozzle does not leak, the nozzle valve is seating properly in the valve body. If drops of fuel collect at a pressure of approximately 200 psi, or less, below popping pressure, the nozzle valve is not seating properly. In this case, the valve body and valve must be removed for cleaning and inspection.

d. If the nozzle proved satisfactory when subjected to the leakage test above, operate handle at a speed of approximately 100 strokes per minute and observe nozzle spray pattern.

e. The nozzle tip has four equally spaced holes,

90 degrees apart.

Size and spacing of these holes determine the spray pattern. If fuel is discharged evenly through all four holes at specified popping pressure, the spray pattern is considered satisfactory. However, if fuel is not discharged evenly from all four holes, a plugged hole(s) is indicated, in which case, the nozzle must be removed and cleaned using a proper size cleaning wire.

f. Install nozzle holder cap nut and tighten it to

60 to 75 foot-pounds torque.

14-41. Nozzle Holder Assembly Installation.

Install the nozzle holder assembly. Refer to opera.

tor and Organizational Maintenance Manual.

14-42. General.

Section VIII. FUEL INJECTION PUMP AND RELATED PARTS a. The fuel injection pump is a single cylinder, opposed plunger, inlet metering, distributor type.

The plungers are operated by an internal cam ring.

The purpose of the pump is to accurately deliver metered quantities of fuel under high pressure to the nozzle holder assemblies through which the fuel is introduced into the engine combustion chambers, at a definite timing in relation to the engine firing cycle, and within the required injection period.

b. On Class 1, Precise Sets, the fuel injection pump is controlled by the hydraulic actuator. The hydraulic actuator operates on the shut down lever to automatically control fuel flow through the fuel injection pump, dependent upon load conditions, and thus controls engine speed and response to load changes.

c. On Class 2, Utility Sets, this fuel injection pump is manually controlled from the control located at the rear of the set. The manual control is connected to the throttle through a cable and sleeve assembly.

speed droop.

Turning the screw outward has the opposite effect.

Regulation of 2-3 percent can be easily attained and adjustment can be made while the engine is operating.

14-43. Fuel Injection Pump Removal and Disassembly.

a. Symptoms and Isolation of Malfunction. A malfunction of the fuel injection pump is usually indicated by loss of engine speed and power, erratic engine speed, failure of engine to start (when electric starter is working correctly), or sudden engine shutdown when there is no fault indication such as low fuel, high coolant temperature, or low oil pressure. To isolate the malfunction to the fuel injection pump, proceed as follows:

(1) Check fuel lines and fuel injection pump for visible signs of leakage.

(2) If engine cannot be started or if it has shut down suddenly, loosen the fuel input line to the fuel injection pump.

the coupling.

If a full line of fuel is available, it may be an indication that the pump has failed. Tighten d. The fuel injection pump also has an integral back-up governor of the mechanical centrifugal

(flyweight) type.

This governor is driven directly off the pump drive shaft without gearing.

(3) While engine is cranking, loosen the input to one of the fuel injectors. If there is no evidence of available fuel, the fuel injector pump has failed.

e. The transfer or supply pump, in the opposite end–of the rotor from the pumping cylinder, is a positive displacement vane type enclosed by the end plate. The pump is self-lubricated by the fuel supply.

(4) Remove timing cover on pump and observe that pump rotates when engine cranks.

(5) Check for 24 Vdc at solenoid terminals on top cover. of injection pump.

f. Fuel shut-off is accomplished electrically by a solenoid mechanism within the fuel pump. When energized, the solenoid opens the metering valve to permit fuel flow to the engine.

g. An external adjustment knurled screw at the rear of the pump housing provides precise control of governor sensitivity by decreasing or increasing the effective length of the governor control spring.

Turning the adjustment screw inward shortens the control spring, making it less sensitive and increasing

14-30

(6) Check solenoid (para 14-46). If no conti-

nuity, replace solenoid.

(7) Refer to table 14-1 for troubleshooting the

fuel injection pump.

b. Removal. (See figure 14-20.)

(1) Refer to the Operator and Organizational

Maintenance Manual and drain fuel day tank and disconnect fuel line to pump.

Table 14-1. Fuel Injection Pump Troubleshooting Chart

MALFUNCTION PROBABLE CAUSE

CORRECTIVE ACTION

1. Fuel not reaching pump.

ON TEST STAND FOLLOWING OVERHAUL

Transfer pump liner locating pin in wrong hole for correct rotation.

Re-install properly. (para 14-45)

2. Fuel delivered from a.

Plunger missing.

transfer pump but not to nozzles.

Cam backwards in housing.

Assemble new plunger. (para 14-45)

Reassemble correctly. (para 14-45)

Metering valve incorrectly c.

Reassemble correctly. (para 14-45)

assembled to metering valve arm.

Install as indicated in paragraph 14-45.

Metering valve spring shim missing.

Hydraulic head vent wires missing.

Head plug screws loose or missing,

3. Inadequate pressure Head plug screws loose or at nozzle missing.

4. Erratic pump output a. Delivery valve sticking,

- surge, poor missing or assembled governor regulation backwards.

Metering valve spring shim missing.

5. Insufficient pump output volume.

Head plug screws loose or missing.

Delivery valve sticking, missing or assembled backwards.

Remove, clean or replace as needed.

Install as indicated in paragraph 14-45.

Remove, clean or replace as needed.

b. Install as indicated in paragraph 14-44.

Hydraulic head vent wires missing.

Head plug screws loose or missing.

head and distributor rotor assembly. (para 14-45

14-31

Table 14-1. Fuel Injection Pump Troubleshooting Chart (Cont)

MALFUNCTION PROBABLE CAUSE

CORRECTIVE ACTION

FOLLOWING INSTALLATION ON ENGINE

Fuel not reaching pump.

Fuel delivered from a. One or more connector transfer pump but screws obstructed.

not to nozzles.

Engine starts hard.

Seizure of distributor rotor.

Failure of electrical shut-off.

Check for cause of seizure. Replace hydraulic a.

parts as necessary. (para 14-46)

Remove, inspect and adjust parts. Replace

One or more connector screws

obstructed.

Engine starts and stops .

Engine does not develop full power or speed.

Failure of electrical shut-off.

One or more connector screws obstructed.

Remove, inspect and adjust parts. Replace parts as necessary.

(para 14-46)

matter, burrs, etc. (para 14-44).

Fuel delivered from transfer pump but not to nozzles.

DURING OPERATION a.

Plungers sticking.

Disassemble and inspect for burrs, corrosion or varnishes.

(para 14-44).

Metering valve sticking or closed.

Passage from transfer pump to metering valve clogged with foreign matter.

Check for governor linkage binding, foreign

Disassemble and flush out hydraulic head.

d. Remove and replace. (para 14-45)

Governor spring worn or

broken.

Remove, replace and readjust. (para 14-45)

Governor linkage loose.

Governor not operating; parts or linkage worn, sticking or binding, or incorrectly assembled.

Rotor badly scored.

Disassemble, inspect parts, replace if

necessary and reassemble. (para 14-45)

Replace hydraulic head and rotor assembly.

a. Correct timing. (para 14-49)

Fuel reaching nozzles a.

Pump timed incorrectly but engine will not to engine.

start.

Excessive fuel leakage past plungers (worn, badly scored).

Cam, shoes or rollers worm d.

Automatic advance faulty or not operating.

c. Remove and replace. (para 14-45).

Replace rotor and hydraulic head assembly.

Remove, inspect, correct and reassemble.

Adjust per paragraph 14-45.

14-32

Table 14-1.

Fuel Injection Pump Troubleshooting Chart (Cont)

MALFUNCTION

PROBABLE CAUSE CORRECTIVE ACTION

DURING OPERATION (Cont) e.

Maximum fuel setting at low limit or too low.

2. Fuel reaching nozzles f.

Throttle arm travel not but engine will not sufficient.

start. (Cont) g.

Rotor badly scored.

Check installation and adjust throttle linkage.

3. Engine starts hard.

Replace hydraulic head and rotor assembly.

and rotor assembly as needed. (para 14-45)

Transfer pump blades worn or broken.

Delivery valve retainer screw loose and leaking or incorrectly installed, b.

Inspect delivery valve stop seat for erosion, tighten retainer screw, or replace head

4. Engine starts and stops.

Plungers sticking.

Metering valve sticking or closed.

Pump timed incorrectly to engine.

Excessive fuel leakage past plungers (worn or badly scored).

Transfer pump faulty, pressure too 1

Cam, shoes or rollers worn.

Automatic advance fault y or not operating.

Disassemble and inspect for burrs, corrosion or varnishes.

Check for governor linkage binding, foreign

Correct timing.

(para 14-49)

Replace rotor and hydraulic head assembly.

Remove and inspect parts. (para 14-45)

Remove, inspect, correct and reassemble,

Adjust governor. (para 14-44)

Governor linkage out of adjustment.

Governor not operating; parts or linkage worn, sticking or binding, or incorrectly assembled.

Maximum fuel setting at low limit or too low.

Disassemble, inspect parts, replace if

necessary and reassemble. para 14-45)

Adjust pump per paragraph 14-48.

m. Shut-off device interfering m. Check and adjust governor linkage dimensions.

with governor linkage.

n. Rotor badly scored.

Replace hydraulic head and rotor assembly.

Failure of electrical shut-off .

Remove, inspect and adjust parts. Replace parts as necessary.

(para 14-46)

14-33

Table 14-1. Fuel Injection Pump Troubleshooting Chart (Cont)

MALFUNCTION PROBABLE CAUSE CORRECTIVE ACTION

Engine starts and stops. (Cont)

DURING OPERATION (Cont) b.

Transfer pump blades worn or broken.

Plungers sticking.

Metering valve sticking or closed.

Cam, roller, or shoes sticking.

Erratic engine operation- surge, a.

Transfer pump blades worn or broken.

misfiring, poor governor regulab.

Delivery valve retainer tion.

screw loose and leaking or incorrectly installed.

Plungers sticking.

Disassemble and inspect for burrs, corrosion or varnishes.

Check for governor linkage binding, foreign

Remove, check for size and burrs and reassemble.

rotor assembly as needed. (para 14-45)

b. Inspect delivery valve stop seat for erosion, tighten retainer screw, or replace head and

Metering valve sticking or closed.

Governor spring worn or broken.

Disassemble and inspect for burrs, corrosion

or varnishes. (para 14-45)

Check for governor linkage binding, foreign

Cam, roller, or shoes sticking.

Remove, check for size and burrs and reassemble.

g. Correct timing. (para 14-49)

Pump timed incorrectly to engine.

Transfer pump faulty, pressure too low.

Automatic advance faulty or not operating.

Remove and inspect parts. (para 14-45)

Remove, inspect, correct and reassemble.

Adjust governor. (para 14-45)

Governor linkage out of adjustment.

Governor not operating; parts or linkage worn, sticking or binding.

Wrong governor spring.

Disassemble, inspect parts, replace if

necessary and repair. (para 14-45)

Pump housing not full of fuel.

Governor sleeve binding on drive shaft.

Remove and replace with proper spring.

Correct and reassemble. (para 14-45)

Operate engine for approximately 5 minutes until pump fills with fuel.

Remove, inspect for burrs, dirt, etc.

14-34

Table 14-1. Fuel Injection Pump Troubleshooting Chart (Cont)

MALFUNCTION

Erratic engine operation- surge, misfiring, poor governor regulation. (Cont)

PROBABLE CAUSE

CORRECTIVE ACTION o.

DURING OPERATION (Cont)

End plate regulating piston sticking.

Remove piston and sleeve and inspect for burrs, corrosion or varnishes. Replace

if necessary. (para 14-45)

Engine does not develop full power or speed.

Variable speed droop device incorrectly adjusted or faulty.

One or more connector screws obstructed.

Transfer pump blades worn or broken.

Delivery valve retainer screw loose and leaking or incorrectly installed.

Plungers sticking.

Replace if necessary. (para 14-47)

and rotor assembly as needed. (para 14-45)

Inspect delivery valve stop seat for erosion, tighten retainer screw, or replace head

d. Disassemble and inspect for burrs, corrosion or varnishes.

Check for governor linkage binding, foreign

Correct timing.

(para 14-44)

Metering valve sticking or closed.

Pump timed incorrectly to engine.

Excessive fuel leakage past plungers (worn or badly scored).

Transfer pump faulty, pressure too low.

Cam, shoes or rollers worn.

Automatic advance fault y or not operating.

Governor linkage out of adjustment.

Governor not operating; parts or linkage worn, sticking or binding, or incorrectly assembled.

Maximum fuel setting at low limit or too low.

n. Wrong governor spring.

Replace rotor and hydraulic head assembly.

Remove and inspect parts.

Remove, inspect, correct and reassemble.

Adjust governor. (para 14-45)

Disassemble, inspect parts, replace if

necessary and reassemble. (para 14-45)

Reset to pump specification. (para 14-48)

Remove and replace with proper spring as in

pump specification. (para 14-45)

14-35

Table 14-1.

Fuel Injection Pump Troubleshooting Chart (Cont)

MALFUNCTION

Engine does not develop full power or speed

(Cont) o.

PROBABLE CAUSE

DURING OPERATION (Cont)

Shut-off device interfering with governor linkage.

Engine smokes black.

r .

Governor high-idle adjustment incorrect

Throttle arm travel not sufficient.

Rotor badly scored.

Pump timed incorrectly to engine.

Cam, shoes or rollers worn.

Automatic advance faulty or not operating.

Maximum fuel setting too high.

Engine smokes blue or white.

Pump timed incorrectly to engine.

Automatic advance fault y or not operating.

Adjust. (para 14-45)

Check installation and adjust throttle

linkage. (para 14-45)

r .

Replace hydraulic head and rotor

assembly. (para 14-45)

Correct timing. (para 14-49)

Remove, inspect, correct and reassemble.

Reset.

(para 14-48)

CORRECTIVE ACTION

Check and adjust governor linkage dimensions.

( p a r a 1 4 - 4 5 )