Cummins EK Begin Spec D, EM Begin Spec W Generator Service manual

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EK Begin Spec D, EM Begin Spec W
Printed U.S.A.
9280505
1295
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by any means, is strictly prohibited.
Table of Contents
SECTION
TITLE
PAGE
SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
1
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
How to Obtain Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
2
AC CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standard Control Panel Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Control Panel Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage Regulator Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage Regulator Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Principle Of Generator Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
2-1
2-1
2-1
2-2
2-3
2-6
ENGINE CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Standard Control Panel Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Optional Control Control Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Control Box Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Engine Control Monitor (A11) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Engine Gauge Senders and Shutdown Switches . . . . . . . . . . . . . . . . . . . . . 3-6
Auxiliary Control Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Sequence Of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
4
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
The Engine Does Not Crank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
The Engine Cranks But Does Not Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
The Engine Runs Until Fault Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
The Engine Lacks Power Or Stable Speed . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Amber Warning Lamp On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
The Green Run Lamps Stay Off But The Set Runs Normally . . . . . . . . . 4-12
There Is No Output Voltage (Engine Speed Is Stable) . . . . . . . . . . . . . . 4-13
Output Voltage Is Too High Or Too Low . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
Output Voltage Is Unstable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
The Field Circuit Breaker Keeps Tripping . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
The Phase Currents Are Unbalanced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
i
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SECTION
5
TITLE
PAGE
SERVICING THE GENERATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Testing The Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Insulation Resistance (Megger) & Polarization Index (PI) Testing . . . . . . . 5-2
Drying the Windings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Exciter Stator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Exciter Rectifier Bridge (Rotating Rectifier Assembly) . . . . . . . . . . . . . . . . 5-5
Exciter Rotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
Main Rotor (Generator Field) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Main Stator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Removing And Disassembling The Generator . . . . . . . . . . . . . . . . . . . . . . . 5-9
Reassembling The Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
6
GOVERNORS AND CARBURETORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Electric Governor Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Linkage Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Magnetic Speed Pickup Unit Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Carburetors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
6-1
6-2
6-3
6-4
WIRING DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
ii
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Safety Precautions
• Be sure battery area has been well-ventilated
Before operating the generator set, read the Operator’s Manual and become familiar with it and the
equipment. Safe and efficient operation can be
achieved only if the equipment is properly operated and maintained. Many accidents are caused
by failure to follow fundamental rules and precautions.
prior to servicing near it. Lead-acid batteries
emit a highly explosive hydrogen gas that can
be ignited by arcing, sparking, smoking, etc..
EXHAUST GASES ARE DEADLY
• Provide an adequate exhaust system to properly expel discharged gases away from enclosed or sheltered areas and areas where individuals are likely to congregate. Visually and
audibly inspect the exhaust daily for leaks per
the maintenance schedule. Make sure that exhaust manifolds are secured and not warped.
Do not use exhaust gases to heat a compartment.
• Be sure the unit is well ventilated.
The following symbols, found throughout this
manual, alert you to potentially dangerous conditions to the operator, service personnel, or the
equipment.
This symbol warns of immediate
hazards which will result in severe personal injury or death.
WARNING This symbol refers to a hazard or unsafe practice which can result in severe personal injury or death.
• Engine exhaust and some of its constituents
are known to the state of California to cause
cancer, birth defects, and other reproductive
harm.
CAUTION
This symbol refers to a hazard or unsafe practice which can result in personal injury
or product or property damage.
MOVING PARTS CAN CAUSE SEVERE
PERSONAL INJURY OR DEATH
• Keep your hands, clothing, and jewelry away
FUEL AND FUMES ARE FLAMMABLE
Fire, explosion, and personal injury or death can result from improper practices.
•
• DO NOT fill fuel tanks while engine is running,
unless tanks are outside the engine compartment. Fuel contact with hot engine or exhaust
is a potential fire hazard.
•
• DO NOT permit any flame, cigarette, pilot light,
spark, arcing equipment, or other ignition
source near the generator set or fuel tank.
•
• Fuel lines must be adequately secured and
free of leaks. Fuel connection at the engine
should be made with an approved flexible line.
Do not use copper piping on flexible lines as
copper will become brittle if continuously vibrated or repeatedly bent.
•
• Be sure all fuel supplies have a positive shutoff
valve.
from moving parts.
Before starting work on the generator set, disconnect battery charger from its AC source,
then disconnect starting batteries, negative (-)
cable first. This will prevent accidental starting.
Make sure that fasteners on the generator set
are secure. Tighten supports and clamps,
keep guards in position over fans, drive belts,
etc.
Do not wear loose clothing or jewelry in the vicinity of moving parts, or while working on electrical equipment. Loose clothing and jewelry
can become caught in moving parts. Jewelry
can short out electrical contacts and cause
shock or burning.
If adjustment must be made while the unit is
running, use extreme caution around hot manifolds, moving parts, etc.
LS-11b
iii
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ELECTRICAL SHOCK CAN CAUSE
SEVERE PERSONAL INJURY OR DEATH
GENERAL SAFETY PRECAUTIONS
• Remove electric power before removing protective shields or touching electrical equipment. Use rubber insulative mats placed on
dry wood platforms over floors that are metal or
concrete when around electrical equipment.
Do not wear damp clothing (particularly wet
shoes) or allow skin surface to be damp when
handling electrical equipment.
• Use extreme caution when working on electrical components. High voltages can cause injury or death. DO NOT tamper with interlocks.
• Follow all applicable state and local electrical
codes. Have all electrical installations performed by a qualified licensed electrician. Tag
and lock open switches to avoid accidental closure.
• DO NOT CONNECT GENERATOR SET DIRECTLY TO ANY BUILDING ELECTRICAL
SYSTEM. Hazardous voltages can flow from
the generator set into the utility line. This
creates a potential for electrocution or property
damage. Connect only through an approved
isolation switch or an approved paralleling device.
HIGH VOLTAGE GENERATOR SETS
(1.9kV to 15kV)
•
Coolants under pressure have a higher boiling
point than water. DO NOT open a radiator or
heat exchanger pressure cap while the engine
is running. Allow the generator set to cool and
bleed the system pressure first.
•
Benzene and lead, found in some gasoline,
have been identified by some state and federal
agencies as causing cancer or reproductive
toxicity. When checking, draining or adding
gasoline, take care not to ingest, breathe the
fumes, or contact gasoline.
•
Used engine oils have been identified by some
state or federal agencies as causing cancer or
reproductive toxicity.
When checking or
changing engine oil, take care not to ingest,
breathe the fumes, or contact used oil.
•
Provide appropriate fire extinguishers and
install them in convenient locations. Consult
the local fire department for the correct type of
extinguisher to use. Do not use foam on electrical fires. Use extinguishers rated ABC by
NFPA.
•
Make sure that rags are not left on or near the
engine.
•
Remove all unnecessary grease and oil from
the unit. Accumulated grease and oil can
cause overheating and engine damage which
present a potential fire hazard.
•
Keep the generator set and the surrounding
area clean and free from obstructions. Remove any debris from the set and keep the floor
clean and dry.
•
Do not work on this equipment when mentally
or physically fatigued, or after consuming any
alcohol or drug that makes the operation of
equipment unsafe.
•
Substances in exhaust gases have been identified by some state or federal agencies as
causing cancer or reproductive toxicity. Take
care not to breath or ingest or come into contact
with exhaust gases.
• High voltage acts differently than low voltage.
Special equipment and training is required to
work on or around high voltage equipment. Operation and maintenance must be done only by
persons trained and qualified to work on such
devices. Improper use or procedures will result
in severe personal injury or death.
• Do not work on energized equipment. Unauthorized personnel must not be permitted near
energized equipment. Due to the nature of high
voltage electrical equipment, induced voltage
remains even after the equipment is disconnected from the power source. Plan the time for
maintenance with authorized personnel so that
the equipment can be de-energized and safely
grounded.
iv
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1. Introduction
Read Safety Precautions and carefully observe all
instructions and precautions in this manual.
ABOUT THIS MANUAL
This service manual is for the EK (begin Spec D)
and EM (begin Spec W) series gasoline and gaseous-fuel generator sets. It includes engine and
generator troubleshooting guides. Engine service
instructions are in the applicable engine service
manual. Operating and maintenance instructions
are in the applicable Operator’s Manual.
TEST EQUIPMENT
Most of the tests in this manual can be done with an
AC-DC multimeter, frequency meter, Wheatstone
bridge (0.001 ohm precision is necessary for measuring stator winding resistance) and load test panel.
HOW TO OBTAIN SERVICE
This manual does not have instructions for servicing printed circuit board assemblies. Always replace a faulty printed circuit board assembly. Attempts to repair a printed circuit board can lead to
costly damage to the equipment.
Always give the complete Model, Specification and
Serial number of the generator set as shown on the
nameplate when seeking additional service information or replacement parts. The nameplate is located on the side of the generator output box.
This manual contains basic (generic) wiring diagrams and schematics that are included to help in
troubleshooting. Service personnel must use the
actual wiring diagram and schematic shipped with
each unit. The wiring diagrams and schematics that
are maintained with the unit should be updated
when modifications are made to the unit.
WARNING Incorrect service or replacement of
parts can result in severe personal injury or
death, and/or equipment damage. Service personnel must be qualified to perform electrical
and mechanical service. Read and follow Safety
Precautions, on pages ii and iii.
1-1
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FIGURE 1-1. TYPICAL GENERATOR SET
1-2
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2. AC Control
meter is from current transformers CT21, CT22 and
CT23.
GENERAL
The control box is mounted on top of the generator,
facing the rear. Figure 2-1 points out the components on the AC control panel. Refer to Section 7 for
wiring connections.
Phase Selector Switch (S21) The selector switch
is used to select the phase for voltage and amperage readings.
STANDARD CONTROL PANEL
COMPONENTS
Scale Indicator Lamps (DS21 and DS22) The
scale indicator lamps indicate whether to read the
upper or lower scales of the voltmeter and ammeter.
Frequency Meter (M23) The frequency meter indicates output frequency in Hertz (Hz) and engine
speed in RPM.
Field Circuit Breaker (CB21) The field circuit
breaker protects the generator from over-excitation.
Wattmeter (M24) The wattmeter indicates output
power in kilowatts (kW).
OPTIONAL CONTROL PANEL
COMPONENTS
Powerfactor Meter (M25) The powerfactor meter
indicates output powerfactor as a percentage of
unity powerfactor.
AC Voltmeter (M21) The voltmeter indicates output
voltage for the phase selected.
Output Voltage Trimmer (R21) The output voltage
trimmer can be used to adjust output voltage plus or
minus five percent of nominal voltage.
AC Ammeter (M22) The ammeter indicates output
amperage for the phase selected. Input to the amOUTPUT
VOLTAGE
TRIMMER
SCALE
INDICATOR
LAMPS
AC
VOLTMETER
FIELD
CIRCUIT
BREAKER
AC
AMMETER
PHASE
SELECTOR
SWITCH
FREQUENCY
METER
POWER
FACTOR
METER
WATTMETER
FIGURE 2-1. AC CONTROL PANEL
2-1
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Because of the differences in engine characteristics, different torque matching may be used for various engine/generator combinations. The switchselectable design of the VRAS-2 provides Onan the
flexibility to test and set the torque-matching function to best suit each engine/generator configuration.
VOLTAGE REGULATOR DESCRIPTION
The design of the Torque Match-2 Voltage Regulator (VRAS-2) provides switch selections that alter
its sensing and command signals in order to
achieve maximum operating performance in a variety of generator sizes and applications. Review the
following, then refer to Voltage Regulator Adjustments for switch locations and settings specific to
your generator set model.
When set to the proper torque-matching switch settings, the VRAS-2 voltage regulator is able to maintain output voltage, within reasonable limits, by reducing the voltage just enough to take full advantage of the engine’s full available power under transient conditions and prevent an unstable response.
These measurements and adjustments are done
while the set is running and require access to uninsulated high voltage parts in the control and power
output boxes.
Non-Torque-Matching (Voltage Sensing): Even
though the voltage regulator can also be switch-selected to a non-torque-matching constant voltage
mode, independent of engine speed, this mode will
not prevent the generator set from stalling during
momentary overload conditions, and is not recommended for use. Consult an Onan service representative before selecting this voltage regulation
mode to make sure that load demands specific to
your installation would not cause an unstable operation of the generator set.
WARNING
HIGH VOLTAGE. Touching uninsulated high voltage parts inside the control and
power output boxes can result in severe personal injury or death. Measurements and adjustments must be done with care to avoid
touching high voltage parts.
For your protection, stand on a dry wooden
platform or rubber insulating mat, make sure
your clothing and shoes are dry, remove jewelry
from your hands and wear elbow length insulating gloves.
Operating Stability
Operating Modes
Because of the differences in exciter and main field
time constants, different gain compensation is required for the various generator sizes and application. The VRAS-2 voltage regulator is switch-selectable to a kW range of operation that best suits the
generator set application.
Torque-Matching (Grequency Sensing): In most
applications, in order for the generator set to accept
the application of a large momentary overload, such
as motor starting, matching the torque characteristics of the engine and generator is required.
2-2
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• Potentiometer R34 – Used to set the frequency
VOLTAGE REGULATOR ADJUSTMENTS
breakpoint. The potentiometer is adjusted at
the factoryand does not require further adjustment.
The VRAS-2 is shown in Figure 2-2. There are three
switch modules and two potentiometers on
VRAS-2.
Adjusting Voltage
• Switch S1 – Selects the overall range of opera-
Use the control panel mounted voltage trimmer, if
provided, for small voltage adjustments. Measure
generator output voltage while the set is running
without load at the nominal frequency. (See Section
6. Governor for instructions on how to adjust the frequency.) If the trimmer does not provide enough adjustment, lock it at its midpoint. Then turn voltage
adjusting pot R32 on the regulator board until rated
voltage is obtained.
tion for the regulator. Refer to Table 2-1.
• Switches S2 and S3 – Determine the mode of
regulation (Torque-Matched, or Non-TorqueMatched). Refer to Table 2-1.
• Potentiometer R32 – Provides adjustability to
increase or decrease generator voltage to
achieve proper setting.
TABLE 2-1. VRAS-2 SWITCH SETTINGS
STABILITY
RANGE
GENSET
kW
RATING
S1-1/4
S1-2/3
20-35
40-50
OFF
OFF
OFF
ON
TORQUE MATCHING MODE
VOLTAGE SENSING
TMB
VOLTS / HZ 60HZ
FREQUENCY SENSING
TMB
VOLTS / HZ 50HZ
TMC
NON-FREQ
TMA
SEMI-FREQ
S2
S3-1/4
S3-2/3
S2
S3-1/4
S3-2/3
S2
S3-1/4
S3-2/3
S2
S3-1/4
S3-2/3
POS 2
OFF
ON
POS 2
ON
ON
POS 2
OFF
OFF
POS 1
OFF
OFF
2-3
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VOLTAGE REGULATOR
(VRAS-2)
S2
S1
R32
R34
THIS JUMPER
MUST BE 3 TO 4
S3
FIGURE 2-2. VOLTAGE REGULATOR ADJUSTMENT POTS AND SELECTION JUMPERS
2-4
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ROTATING
RECTIFIERS
EXCITER
ROTOR
MAIN
ROTOR
EXCITER
STATOR
MAIN
STATOR
F1 (+)
T10
T9
T8
T7
T4
F2 (–)
OUTPUT
VOLTAGE
SENSING
LEADS
TB21
32
VRAS-2
(300–2880)
VOLTAGE
REGULATOR
(VR21)
31
T10
T9
T4
T8
T7
26
25
24
23
1
22
2
3
4 5 6
7 8
9 10
21
FIELD
CIRCUIT
BREAKER
CB21
VOLTAGE
TRIMMER
R21
(optional)
FIGURE 2-3. TYPICAL VOLTAGE REGULATING CIRCUIT
2-5
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bridge (rotating rectifiers) mounted on the exciter rotor converts exciter output (3-phase AC)
to DC. The exciter rotor is mounted on the main
rotor shaft.
5. Exciter output current is proportional to exciter
field current.
6. The automatic voltage regulator (VRAS-2) regulates exciter field current by comparing generator output voltage and frequency with reference values.
7. Exciter field current is supplied by the generator stator through the voltage regulator. Residual field magnetism initiates “self-excitation”
during startups.
PRINCIPLE OF GENERATOR OPERATION
1. The generator field (main rotor) is rotated by
the engine to induce output current (AC) in the
main stator windings.
2. Generator output current is proportional to field
strength, which is varied to match the load.
Output voltage and frequency are held
constant by the voltage regulator and engine
governor, respectively.
3. Generator field strength is proportional to field
current, which is supplied by the exciter.
4. The exciter field (stator) induces current in the
exciter rotor windings. A full wave rectifier
SELF-EXCITED GENERATORS
ELECTRICAL POWER OUTPUT
VRAS-2
MAIN STATOR
EXCITER
ROTOR
AND
STATOR
MAIN ROTOR
ROTATING
MECHANICAL
POWER
INPUT
FIGURE 2-4. SCHEMATIC OF GENERATOR OPERATION
2-6
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3. Engine Control
Reset / Lamp Test / Panel Lamp Switch (S11) The
switch is pushed to the Reset position (momentary
contact) to reset the engine control to restore operation following a fault shutdown. The Run / Stop / Remote switch must be in the Stop position for reset to
occur. The Lamp Test position (momentary contact) lights all the fault indicator lamps. Replace
lamps that do not light. Also, this switch has a light
which lights following a fault or emergency shutdown. The light remains lit until the engine control
has been reset. The Panel Lamp position lights the
panel illumination lamp.
CONTROL PANEL
The control box is mounted on top of the generator,
facing the rear. Figure 3-1 shows the components
on the engine control panel.
STANDARD CONTROL PANEL
COMPONENTS
Run/Stop/Remote Switch (S12) The switch is
pushed to the Run position to start and run the generator set and to the Stop position to stop the set.
The Remote position allows a remote controller to
automatically run the set. The switch must be in the
Stop position when the reset switch (described
next) is used to restore generator set operation following a fault shutdown.
OIL PRESSURE
GAUGE
Coolant Temperature Gauge (M12) The coolant
temperature gauge indicates engine coolant temperature.
Oil Pressure Gauge (M11) The oil pressure gauge
indicates engine oil pressure.
RUN/STOP/REMOTE
SWITCH
PANEL
LIGHT
COOLANT
TEMPERATURE
GAUGE
RESET/LAMP TEST/
PANEL LIGHT SWITCH
INDICATOR
LAMPS
HOUR
METER
DC
VOLTMETER
OIL TEMPERATURE
GAUGE
TACHOMETER
EMERGENCY STOP
BUTTON
FIGURE 3-1. ENGINE CONTROL PANEL
3-1
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DC Voltmeter (M13) The DC voltmeter indicates
voltage across the battery terminals during operation.
Hour Meter (M14) The hour meter indicates the accumulated number of hours the set has run. It cannot be reset.
Panel Lamp (DS11) The panel lamp illuminates the
control panel.
Detector-7 Fault and Status Indicator Lamps
(A12)
• Run (Green) This lamp indicates that the gen•
•
•
•
•
•
erator set is running and that the starter has
been disconnected.
Pre Low Oil Pressure (Yellow) This lamp indicates that engine oil pressure is abnormally low
(less than 20 psi [138 kPa]). Normal operating
range is 35 to 60 psi (241 to 414 kPa).
Low Oil Pressure (Red) This lamp indicates
that the engine shut down because of excessively low engine oil pressure (less than 14 psi
[97 kPa]).
Pre High Engine Temperature (Yellow) This
lamp indicates that engine coolant temperature is abnormally high (greater than 220° F
[104° C]).
High Engine Temperature (Red) This lamp
indicates that the engine shut down because of
excessively high engine coolant temperature
(greater than 230° F [110° C]).
Overcrank (Red) This lamp indicates that the
engine shut down because it did not start during the timed cranking period (approximately
75 seconds, including two rest periods).
Overspeed (Red) This lamp indicates that the
engine shut down because of overspeed.
539-0741c2
FIGURE 3-2. DETECTOR-12 INDICATOR LAMPS
3-2
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than the reserve necessary to run the set at full
load for the prescribed number of hours. The
customer has to make connections to use this
lamp.
OPTIONAL CONTROL PANEL
COMPONENTS
Oil Temperature Gauge (M15) The oil temperature
gauge indicates engine oil temperature.
• Fault 1 (Red) This lamp indicates that the en-
Tachometer (M16) The tachometer indicates engine speed in RPM.
gine shut down because of a system fault. The
customer has to make connections to use this
lamp. The lamp is a part of a 10 second time
delay shutdown circuit. The customer can
make reconnections for non-timed shutdown.
See Engine Control Monitor (ECM).
Emergency Stop Button (S14) The emergency
stop button is a red, push-in switch used to stop the
engine. The button lights up when it is pushed in.
The button has to be pulled out and the engine control reset to restore operation.
• Fault 2 (Red) This lamp indicates that the en-
Detector-12 Fault and Status Indicator Lamps
(A12) The Detector-12 control panel has the five following indicator lamps in addition to the standard
seven.
gine shut down because of a system fault. The
customer has to make connections to use this
lamp. The lamp is part of a non-time delay shutdown circuit. The customer can make reconnections for 10 second time delay shutdown.
See Engine Control Monitor (ECM).
• Low Engine Temperature (Yellow) This lamp
indicates that engine temperature is less than
70° F, and the possibility that the engine might
not start.
• Low Fuel (Yellow) This lamp indicates that the
fuel level in the supply tank has dropped to less
• Switch-off (Flashing Red) This lamp indicates that the Run / Stop / Remote switch is in
the Stop position, which prevents remote, automatic operation.
3-3
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ENGINE
CONTROL
MONITOR A11
TIME DELAY
START/STOP
MODULE A15
VOLTAGE
REGULATOR
(VRAS-2)
TERMINAL BOARD
TB21
OVERSPEED
MODULE
RUN RELAYS K11
(NOT SHOWN – MOUNTED ON
A BRACKET IN FRONT OF A11)
ES1561s1
FIGURE 3-3. ARRANGEMENT OF COMPONENTS INSIDE THE CONTROL BOX
CONTROL BOX INTERIOR
Fuses
The ECM has five replaceable fuses to protect it
from overloads and groundfaults. They are:
Figure 3-3 shows the arrangement of components
inside the control box, including the engine control
monitor and some of the auxiliary components under following headings.
F1
F2
F3
F4
F5
ENGINE CONTROL MONITOR (A11)
Starter solenoid circuit, 20 amps
Fuel solenoid (switched B+) circuits, 20 amps
Continuous B+ out to remote circuits, 15 amps
ECM circuits, 5 amps
Engine gauge circuits, 5 amps.
Function Selection Jumpers
The heart of the engine control system is the engine
control monitor (ECM) (Figure 3-4). It is a printed
circuit board assembly mounted on the back wall of
the control box. It starts and stops the engine in response to the control panel switches, engine sensors and remote control signals.
Newer ECM boards have six selection jumpers that
can be repositioned to provide the following timed
or non-timed warnings or timed or non-timed shutdowns with warnings:
W1 Jumper Position (jumper W8 must be in the B
position):
A Non-timed warning under FLT 2 conditions.
B Non-timed shutdown and warning under
FLT 2 conditions.
C Timed warning under FLT 2 conditions.
D Timed shutdown and warning under FLT 2
conditions.
Terminals and Connectors
See Pages 7-5 through 7-8 for the appropriate connection and schematic drawings for the DC control
system. See Page 7-10 for typical customer connections at terminal boards TB1 and TB2 on the
ECM and page 7-11 if the set is also equipped with
the auxiliary relay board.
3-4
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A Warning under Pre-Low Oil Pressure
conditions.
W2 Jumper Position (jumper W9 must be in the B
position):
A Non-timed warning under FLT 1 conditions.
B Non-timed shutdown and warning under
FLT 1 conditions.
C Timed warning under FLT 1 conditions.
D Timed shutdown and warning under FLT 1
conditions.
W6 Jumper Position:
A Warning under Pre-High Engine Temperature conditions.
B Shutdown and warning under Pre-High
Engine Temperature conditions.
W7 Jumper Position:
8
7
6
5
4
3
2
B Shutdown and warning under Pre-Low
Oil Pressure conditions.
W8 Jumper Position:
A Warning while running or during standby
under FLT 2 conditions.
B Allows selection of functions with W1
jumper.
W9 Jumper Position:
A Warning while running or during standby
under FLT 1 conditions.
B Allows selection of functions with W2
jumper.
1
6
5
4
3
2
1
FIGURE 3-4. ENGINE CONTROL MONITOR FUSES AND FUNCTION SELECTION JUMPERS
3-5
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Always use pipe thread sealant on gauge senders
and warning and shutdown switches.
ENGINE GAUGE SENDERS AND
SHUTDOWN SWITCHES
Figure 3-5 shows the locations of the gauge senders and the coolant temperature and oil pressure
sensing switches to which the ECM responds. The
switches function by closing the fault or warning circuit to the engine chassis ground (battery negative [-]).
CAUTION
Teflon tape is not recommended for
switches and senders that are grounded to the
engine by thread contact as it may interfere with
the ground path.
T26 OF ENGINE
HARNESS
LOW OIL PRESSURE
SENSOR (S1)
LOW ENGINE TEMPERATURE,
PRE-HIGH ENGINE TEMPERATURE, &
WATER TEMPERATURE SENDER
PRE-LOW OIL PRESSURE
SENSOR (S5)
OIL PRESSURE
SENDER (E1)
FIGURE 3-5. ENGINE SENSOR LOCATIONS
3-6
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with the high engine temperature cutout switch to
shut down the engine and light the High Engine
Temperature lamp or in parallel with the pre-high
engine temperature switch to light the Pre High Engine Temperature light only. See Figure 3-6.
Low Coolant Level Cutout Switch
When coolant level in the radiator top tank falls below the switch sensor, the switch closes the circuit to
ground. This switch may be connected in parallel
RADIATOR
TOP TANK
LOW COOLANT
LEVEL SWITCH
TO ECM TB2-8 (HIGH ENGINE TEMP), OR
ECM TB2-10 (PRE HIGH ENGINE TEMP)
FIGURE 3-6. LOW COOLANT LEVEL SWITCH
3-7
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Coolant Temperature Gauge and Warning
Light Circuits
An electronic PCB assembly is mounted on the
back of the coolant temperature gauge (M12) with
three terminal nuts. The PCB assembly carries two
relays that provide signals for the low coolant and
pre-high temperature warning lamps on the basis of
the gauge sender output. See Figure 3-7.
PCB MOUNTING ON BACK OF GAUGE
GAUGE AND PCB CONNECTIONS
FIGURE 3-7. COOLANT TEMPERATURE GAUGE
3-8
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occurs within 2100 to 2300 RPM (50 or 60 Hz
sets).
Turn adjustment screw clockwise to increase
trip speed.
2. Replace the switch if the cutout speed adjustment results in an air gap between the magnet
and the fly arm of less than 0.005 inches (0.13
mm).
3. Torque the center rotor bolt to 40 ft-lbs (54
N•m) when replacing the switch.
AUXILIARY CONTROL COMPONENTS
The set might be equipped with one or more of the
following components.
Mechanical Overspeed Switch (Standard)
The mechanical overspeed switch is bolted to the
end of the generator rotor shaft.
1. Check overspeed cutout RPM and turn the adjustment screw, if necessary, so that shutdown
ADJUST
SCREW
GENERATOR
SHAFT
AIR GAP (NOT LESS
THAN 0.005 IN. (13 MM)
SWITCH
CONTACTS
END
BELL
FIGURE 3-8. OVERSPEED SWITCH ASSEMBLY
3-9
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cated in any of 3 positions (A, B, C) independently of
each other.
Auxiliary Relay Board (ARB)
The following describes the design/functional criteria for the ARB with a Detector-7 or -12 Genset control. The board is mounted directly on top of the
ECM using standoffs and has access holes for the
fuses located on the ECM. There are two versions
of the ARB; with and without the set of 12 Fault relays (Figure 3-9). Page 7-11 is a detailed connection diagram for the ARB.
Jumper Position A (Run): The relay operates
as a Run relay, energizing when Switched B+ is
applied from the ECM.
Jumper Position B (Common Alarm): The
relay operates as a Common Alarm relay. The
relay energizes any time there is an engine
shutdown. This signal is provided from the
ECM.
Jumper Position C (Isolated): The relay operates as an Isolated relay. The relay coil is energized by a customer applied B+ signal
through the terminal block; TB3-1 for relay K1,
TB4-1 for relay K2, and TB5-1 for relay K3.
Terminal Blocks:
TB1 – ARB TB1 and ECM TB1 are identically numbered and provide the same remote control connection points. Note that additional terminals are provided for terminals 5, 7, and 10 of ARB TB1.
Jumpers W11, W12, and W13 perform the same
functions for their respective relays; W11 for relay
K1, W12 for relay K2, and W13 for relay K3. They
can be located in two different positions (A, B) independently of one another.
TB2 through TB5 – Connection points for relays
K1 through K3. TB2 provides the N/O and N/C connections (three form ‘C’ contacts for each relay).
TB3 through TB5 provide the common connection
points (TB3 for K1, TB4 for K2, and TB5 for K3).
Jumper Position A: The relay operates isolated from the board. The customer provides
the circuit completion through terminal block;
TB3 for relay K1, TB4-5 for relay K2, and TB5-5
for relay K3. The customer can operate the
relay with switched ground logic or use this
relay in the middle of more complex logic circuits if needed.
Jumper Position B: The relay operates with
the coil connected to ground through the board
connections. The coil will require a B+ signal to
energize with the jumper in this position.
TB6 and TB7 – Connection points for fault relays
K4 through K15. Three terminals are provided for
each relay, which are labeled COM, N/C, and N/O.
Plug-In Relays (K1, K2, K3):
The ARB can be equipped with one to three 3-pole,
double-throw relays. These relays (K1, K2, K3) are
field changeable plug-in relays for easy field addition and replacement.
The relay contact ratings are:
• 10 amps at 28 VDC or 120 VAC, 80% PF
• 6 amps at 240 VAC, 80% PF
• 3 amps at 480 VAC, 80% PF
Fault Relays (K4 through K15):
These optional relay modules are used to operate a
remote alarm annunciator that has an independent
power source. This allows the use of either AC or
DC for alarm drives. The relays are energized
through the latching relays on the ECM and provided N/O and N/C contacts for each external alarm
connection.
Each relay can be operated as a RUN, COMMON
ALARM, or ISOLATED COIL with the changing of a
jumper.
Jumper Positions for Plug-In Relays:
The 12 relays with form ‘C’ contacts are rated:
Jumpers W1, W2. and W3 perform the same functions for their respective relays, W1 for relay K1, W2
for relay K2, and W3 for relay K3. They can be lo-
• 10 amps at 120 VAC
• 10 amps at 30 VDC
3-10
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JUMPERS
RUN RELAY
MODULE(S)
K1
K2
JUMPERS
K3
J1 AND J2 WIRE
HARNESS PLUG
CONNECTIONS
FROM ECM
TB6, TB7 AND
RELAYS K4
THROUGH K15
ARE OPTIONAL
300-4111c
FIGURE 3-9. AUXILIARY RELAY BOARD (ARB)
3-11
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Over/Under Voltage Module (A17)
The set can be equipped with an adjustable voltage-sensitive relay usually connected into the Fault
1 circuit (Detector-12 controls only) to shut down
the set when the output voltage is over or under
nominal voltage by the preselected percentage
(typically 10 percent over and under).
This module has an adjustable time delay relay
(K17) to prevent nuisance tripping. An adjustment
of 25 percent is equivalent to about 2.5 seconds
delay.
Recalibrate the module as follows before installing
it on 139/240 VAC or 277/480 VAC sets.
*
*
WARNING HAZARDOUS VOLTAGE. Touching
uninsulated high voltage parts inside the control panel box can result in severe personal injury or death. Measurements and adjustments
must be done with care to avoid touching high
voltage parts.
For your protection, stand on a dry wooden platform or rubber insulating mat, make sure your
clothing and shoes are dry, remove jewelry and
wear elbow length insulating gloves intended
for hazardous voltages.
1. Remove the two screws that secure the top to
the case of the module and withdraw the top
assembly.
2. Adjust the SET pot for the UNDER setpoint on
the face of the top assembly to 75 percent.
3. Apply single-phase, 60 Hertz, 104.25 VAC
across terminals L and N.
4. Adjust pot R25 on the PC board until the relay
trips (de-energizes).
5. Adjust the SET pot for the OVER setpoint on
the face of the top assembly to 125 percent.
6. Apply single-phase, 60 Hertz, 173.75 VAC
across terminals L and N.
7. Adjust pot R26 on the PC board until the relay
trips (energizes).
8. Repeat the above steps until no adjustments
are necessary.
9. Reassemble the module.
10. On the module nameplate mark out the factory
calibration value for monitored voltage (120 V)
and write in 139 V.
**
* CONNECTED TO TB11-45 WHEN GENERATOR IS PARALLELED.
** CONNECTED TO GENERATOR LEAD LO
WHEN THE GENERATOR IS CONNECTED
FOR SINGLE PHASE.
FIGURE 3-10. OVER/UNDER VOLTAGE
MODULE
3-12
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Over/Under Frequency Module (A19)
The set can be equipped with an adjustable frequency-sensitive relay to shut down the set when
the output frequency (Hz) is over or under nominal
frequency by the preselected amount. It is usually
connected into the Fault 2 circuit (Detector-12 controls only) if the over/under voltage module is also
provided. Set points are typically 5 Hertz over and
under nominal frequency (50 or 60 Hertz) and reset
points 3 Hertz over and under.
3003141
FIGURE 3-11. OVER/UNDER FREQUENCY
MODULE
3-13
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justable to delay starts from 1 to 15 seconds to prevent nuisance starts in installations where momentary power interruptions are frequent. It is adjustable to delay stops 1 to 30 minutes to allow the
prime source of power time to stabilize.
Time Delay Start/Stop Module (A15)
The set can be equipped with a module to delay
starting and stopping when the start and stop signals are received from the remote controller. It is ad-
TIME DELAY STOP POTENTIOMETER
TIME DELAY START
POTENTIOMETER
TB1
A11-TB1-2
(PRIMARY START DISCONNECT)
A11-TB1-6
(REMOTE START)
A11-TB1-3
(SECONDARY START DISCONNECT)
REMOTE
CONTROL
A11-TB1-5
(GND)
A11-TB1-7
(B+)
A11-TB1-7
(B+)
ES1855s
FIGURE 3-12. TIME DELAY START/STOP MODULE
3-14
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10. Relays K2 and K3 are de-energized (by latching relay K6) causing shutdown to occur if the
engine does not start within 75 seconds. The
Overcrank indicator lamp lights and common
alarm terminal TB1-4 is powered.
SEQUENCE OF OPERATION
The sequence of operation is as follows. Refer to
the schematic on Page 7-6 or 7-8.
1. The ECM is powered by cranking battery voltage (12 VDC). Terminal TB1-9 is connected to
battery positive (+) and connector P1-6 to battery negative (-).
The ECM has a cycle crank feature where the engine is cranked for three 15 second periods alternated with two 15 second rest periods.
2. The starting cycle begins when relay K7 is
powered, either manually by pushing the panel
Run switch, or automatically by a remote controller connected at terminal TB1-6. (The panel
switch must be in the Remote position for remote, automatic operation.)
11. Relay K3 is de-energized (by latching relay K6)
causing shutdown to occur during operation
when a low oil pressure, high engine temperature or engine overspeed condition is sensed
or the optional emergency stop button is
pressed. The appropriate fault indicator lamp
lights and common alarm terminal TB1-4 is
powered. (There is no fault lamp for emergency
stop. The switch button will light, however, and
the light in switch S11.)
3. Relay K7 powers relays K2 and K3.
4. Relay K2 powers the engine gauges and terminal TB1-10, to which the fuel solenoid and ignition module are connected.
The low oil pressure and high engine temperature shutdowns have 10 second time delays to
allow oil pressure and engine temperature to
stabilize during startup.
5. Relay K3 powers terminal TB1-8 to which starter relay K4 is connected. Engine cranking begins.
6. The engine starts and runs up to governed
speed in a matter of seconds.
12. To restore operation after a shutdown fault has
been serviced, reset latching relay K6 by pushing the panel Stop switch and then the Reset
switch. The set should run or be ready to run
when the panel switch is pushed to Run or to
Remote.
7. The starter is disconnected when engine
speed gets to about 500 RPM. This is done by
relay K10 or K14, whichever acts first to open
the circuit powering relay K3.
8. Relay K10 is powered by the generator output
voltage (120 VAC) through plug-in connectors
P1-1 and P1-2. The remote Run indicator lamp
should light (connected through terminal
TB1-3).
If the emergency stop switch has been used, the
control will have to be reset to restore operation.
First pull the emergency stop switch button and
then push the panel Stop and Reset switches.
9. Relay K14 is powered by the engine-driven
battery charging alternator (12 VDC) through
plug-in connector P1-3. The panel Run indicator lamp should light. Relays K10 and K14 are
redundant.*
13. The set is stopped manually by pressing the
panel Stop switch or automatically by a remote
controller. (The panel switch must be in the Remote position for remote, automatic operation.)
* On older ECM boards (those having cartridge-type fuses):
• If the starter disconnects normally but the panel Run indicator lamp does not light, the DC (K14) starter disconnect circuit is
not working.
• If the starter disconnects normally but neither the panel nor the remote Run indicator lamps light, the AC (K10) starter disconnect circuit is not working.
* On newer ECM boards (those having automotive-type fuses):
• If the starter disconnects normally but neither the panel nor the remote Run indicator lamps light, the AC (K10) starter disconnect circuit is not working.
• Both the remote and the panel Run indicator lamps will light even if the DC (K14) starter disconnect circuit is not working.
Check the DC voltmeter to determine whether or not the battery charging alternator is working.
3-15
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4. Troubleshooting
WARNING
These troubleshooting charts are designed to help
you think through generator set problems. To save
time troubleshooting, read the entire manual ahead
of time to understand the generator set. Try to think
through problems. Go over what was done during
the last service call. The problem could be as simple
as an empty fuel tank, closed fuel shutoff valve,
loose wire, blown fuse or tripped circuit breaker.
Hazards present in troubleshooting
can cause equipment damage, severe personal
injury or death. Troubleshooting must be performed by qualified persons who know about
fuel, electrical and machinery hazards. Read
the Safety Precautions page and carefully observe all instructions and precautions in this
manual.
THE ENGINE DOES NOT CRANK
The Run-Stop-Remote switch is at Stop.
(The Switch-Off light will be flashing, if
provided.)
Push the Run-Stop-Remote switch to Run or Remote.
Pull the Emergency Switch button. To reset the engine control, push the Run-Stop-Remote switch to
Stop and the Reset switch to Reset. Then push the
Run-Stop-Remote switch to Run or Remote.
The Emergency Stop switch has been
used. (The switch button and switch S11
will light.)
The remote control circuit is faulty.
Push the Run-Stop-Remote switch to Run. If the engine cranks, find and repair the fault in the remote control circuit.
A Fault Shutdown is being indicated by
one of the red lights on the control panel.
Service the set as necessary. To reset the engine control, push the Run-Stop-Remote switch to Stop and
the Reset switch to Reset. Then push the Run-StopRemote switch to Run or Remote.
A Lo Shutdown is being indicated on the
day tank pump control panel (if provided).
Determine the cause and service as necessary. To reset the engine control, push the Run-Stop-Remote
switch to Stop and the Reset switch to Reset. Then
push the Run-Stop-Remote switch to Run or Remote. Note that the engine control will shut down unless the day tank control has been reset first.
Continued on next page.
4-1
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE ENGINE DOES NOT CRANK (CONT.)
Continued from previous page.
Cranking voltage is too low to crank the
engine.
Clean and tighten or replace the battery cable connectors and cables at the battery and the set.
Recharge or replace the battery. Specific gravity for a
fully charged battery is approximately 1.260 at 80° F
(27° C).
If the set is in standby service, install a battery charger.
Replace the engine-driven battery charging alternator
if normal battery charging voltage is not between 12
and 15 volts.
Fuse F1 on the ECM (A11) board has
blown.
Replace the fuse with one of the same type and amp
rating.
If fuse F1 blows again, the wire between ECM terminal
TB1-8 and starter solenoid terminal S may be loose or
damaged, causing a short to ground. Repair as necessary.
If fuse F1 still blows, service or replace the starter or
the solenoid according to the engine service manual.
Check for battery voltage (12 VDC) between ECM terminal TB1-9 (B+) and the grounding stud (–) on the
floor of the control cabinet. Check, clean and tighten
the connectors at both ends and replace the wire if it is
damaged.
The wire between ECM terminal TB1-9
and starter solenoid terminal BAT is
loose, damaged or missing.
Continued on next page.
4-2
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by any means, is strictly prohibited.
WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE ENGINE DOES NOT CRANK (CONT.)
Continued from previous page.
A grounding strap between the control
box and the battery negative (–) terminal
is loose, damaged or missing.
Check for electrical continuity (zero ohms) between
the grounding stud on the floor of the control box and
the battery negative (–) terminal. If there is no electrical continuity, check for loose, damaged or missing
grounding straps and repair as necessary.
The Run-Stop-Remote switch (S12) or
wiring is faulty.
Disconnect pin connector J4 from the ECM board and
check for electrical continuity (zero ohms) between
switch terminals 2 and 3 when the switch is in the Run
position and between terminals 1 and 2 when it is in the
Remote position. Replace the switch if either set of
contacts is faulty.
If the switch works, check for electrical continuity (zero
ohms) between J4-6 and J4-7 on the wire harness
when the switch is in the Run position and between
J4-5 and J4-7 when the switch is in the Remote position. Replace the wire harness if there is no electrical
continuity in either position of the switch.
The ECM is faulty. (Check fuse F1 again.)
Push the Run-Stop-Remote switch to Run and check
for battery voltage (12 VDC) between ECM terminal
TB1-8 and the grounding stud on the floor of the control box. If there is no voltage when the switch is in the
Run position, replace the ECM.
The wire between ECM terminal TB1-8
and starter solenoid terminal SW is loose,
damaged or missing.
Push the Run-Stop-Remote switch to Run and check
for battery voltage at starter solenoid terminal SW. If
there is no voltage repair the wiring as necessary.
The starter motor or solenoid is malfunctioning.
If there is voltage at starter solenoid terminal SW but
the motor does not function, repair or replace the starter motor or solenoid according to the engine service
manual.
4-3
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by any means, is strictly prohibited.
WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE ENGINE CRANKS BUT DOES NOT START
When the Run-Stop-Remote switch is in the Run position, the control will attempt to crank the engine for approximately 75 seconds (including two rest periods) and then the red OVERCRANK lamp will light if the engine does not start. If
the OVERCRANK lamp comes on, reset the control by pushing the Run-Stop-Remote switch to Stop and the Reset
switch to Reset. Then push the Run-Stop-Remote switch to Run or Remote.
Open any closed shutoff valve in the fuel line supplying
the engine.
The engine is not getting fuel.
Check fuel solenoid and related wiring. Repair or replace as needed.
Fill the main fuel supply tank if the set is gasoline or
propane fueled. For natural gas fueled sets, check
with the gas utility.
The air cleaner is blocked.
Service as necessary.
The engine ignition system is malfunctioning (ignition coil, distributor, spark
plugs, high tension spark plug and coil
cables and timing.
Service as necessary. Refer to wiring diagrams in Section 7.
Clean and rebuild gasoline carburetors with the appropriate carburetor kit according to the kit instructions. Adjust fuel mixture and choke (refer to Section
6).
The carburetor fuel passages are
clogged or the choke needs adjustment.
Continued on next page.
4-4
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by any means, is strictly prohibited.
WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE ENGINE CRANKS BUT DOES NOT START (CONT.)
Continued from previous page.
Fuse F2 on the ECM board (A11) has
blown.
Replace the fuse with one of the same type and amp
rating.
If fuse F2 blows again, the wire between ECM terminal
TB1-10 and engine block terminal T26 may be loose
or damaged, causing a short to ground. Repair as necessary.
If fuse F2 still blows, the wire between fuel solenoid K1
and terminal T26 may be loose or damaged, causing a
short to ground. Repair as necessary.
Fuel solenoid K1 is faulty (does not
open).
Connect the terminal on fuel solenoid K1 to the BAT
terminal on starter relay K4 with a jumper wire. Replace the fuel solenoid if it does not “click” each time
power is connected.
Low engine temperature is causing too
low a cranking speed for starting.
Plug in, repair or install engine coolant and engine oil
heaters.
Replace the engine oil if it is not of the recommended
viscosity for the ambient temperature.
Continued on next page.
4-5
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by any means, is strictly prohibited.
WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE ENGINE CRANKS BUT DOES NOT START (CONT.)
Continued from previous page.
While cranking the engine, measure voltage directly
across the battery terminals and then immediately
across the starter motor terminal and the grounding
bolt on the block. Cable, terminal or relay contact resistance is too high if the difference is more than 2
volts. Service as necessary.
Cranking voltage is too low to reach required cranking speed.
Recharge or replace the battery. Specific gravity for a
fully charged battery is approximately 1.260 at 80° F
(27° C).
Replace the engine-driven battery charging alternator
if normal battery charging voltage is not between 12
and 15 volts.
The ECM is faulty. (Check fuse F2 again.)
While cranking, check for battery voltage at the terminal TB1-10 on the ECM. Replace the ECM if there is
no voltage at the terminal.
The engine is worn or malfunctioning mechanically.
Service according to the engine service manual.
4-6
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE ENGINE RUNS UNTIL FAULT SHUTDOWN (RED SHUTDOWN LAMP ON)
Reset the ECM by pushing the Run-Stop-Remote
switch to Stop and the Reset switch to Reset and restart the set, monitoring engine speed. Readjust the
cutout speed if it is lower than specified. See Section 3,
Engine Control.
The OVERSPEED lamp comes on when
the engine shuts down.
Adjust the governor according to Section 6, Governors.
Mechanical Governor: Service or replace the injection pump unit if the set still shuts down due to overspeed.
Electronic Governor: If the governor cannot be adjusted to prevent shutdown due to overspeed, check
for binding in the linkage. Repair and adjust the linkage
as necessary. (A spring inside the actuator will resist
movement, which is normal.)
If the set still shuts down due to overspeed, re-install
the magnetic speed pick-up unit to make sure the
clearance with the flywheel gear teeth is correct. Replace the speed-pickup unit if output voltage at cranking speed is less than 2.5 VDC as measured at terminals 10 (–) and 11 (+) on the governor controller.
Disconnect the actuator lead connected at governor
controller terminal 5 and connect it to the negative (–)
terminal of the cranking battery. Then disconnect the
lead connected at terminal 4 and touch it to the battery
positive (+) terminal. Replace the actuator unit if it
does not drive the linkage through its full travel when
power is connected or return it when power is disconnected.
Replace the governor controller if the set still shuts
down due to overspeed.
Continued on next page.
4-7
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by any means, is strictly prohibited.
WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE ENGINE RUNS UNTIL FAULT SHUTDOWN (CONT)
Continued from previous page.
Reset the ECM by pushing the Run-Stop-Remote
switch to Stop and the Reset switch to Reset and fill
up with as much engine oil as necessary and repair all
oil leaks.
The LOW OIL PRESSURE lamp comes
on when the engine shuts down.
If the set still shuts down due to low oil pressure, disconnect the wire to fuel solenoid K1 (to keep the engine from starting) and observe oil pressure while
cranking the engine. Service the lubricating oil system
according to the engine service manual if oil pressure
is less than 10 psi. Replace the low oil pressure cutout
switch if oil pressure is greater than 10 psi. See Figure
3-5, Engine Control to locate the switch.
Reset the ECM by pushing the Run-Stop-Remote
switch to Stop and the Reset switch to Reset and fill
up with as much engine coolant as necessary and repair all leaks.
The HIGH ENGINE TEMPERATURE
lamp comes on when the engine shuts
down.
If the set still shuts down due to high engine temperature, start the engine and observe coolant temperature as the system heats up. If shutdown occurs before
the coolant reaches 230° F (110° C), replace the high
engine temperature cutout switch. If coolant temperature exceeds 230° F (110° C), clean and service the
entire cooling system as required to restore full cooling
capacity. See Figure 3-5 in Section 3, Engine Control,
to locate the switch.
Service as required. (The customer has supplied the
system fault indicating switches. By means of selection jumpers, either fault may be chosen to display the
warning only. See Section 3, Engine Control.)
The FAULT 1 or FAULT 2 lamp comes on
when the engine shuts down.
If the set is equipped with the optional low frequency
shutdown feature and the red FAULT 1 or FAULT 2
lamp is on, the set probably ran out of fuel. Service as
required.
4-8
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE ENGINE LACKS POWER OR STABLE SPEED
Fuel delivery to the set is inadequate.
Check for and replace clogged fuel lines and filters.
Check for air in the fuel lines and repair all air leaks.
Measure the vertical distance between the fuel lift
pump on the engine and the bottom of the dip tube in
the supply tank. Make necessary provisions so that lift
does not exceed 6 feet (1.8 metres).
The fuel is contaminated.
Connect the set to a container of fuel of known quality
and run the set under various loads. Replace the contents of the fuel supply tank if there is a noticeable improvement in performance.
The engine air filter element is dirty.
Replace the air filter element.
Continued on next page.
4-9
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE ENGINE LACKS POWER OR STABLE SPEED (CONT.)
Continued from previous page.
Adjust the governor according to Section 6, Governors.
The governor adjustment is incorrect.
Electronic Governor: If the governor cannot be adjusted for full power or stable speed, shut down the set
and check for binding in the linkage. Repair and adjust
the linkage as necessary. (A spring inside the actuator
will resist opening the movement, which is normal.)
Re-install the magnetic speed pick-up unit to make
sure the clearance with the flywheel gear teeth is correct. Replace the speed-pickup unit if output voltage at
cranking speed is less than 2.5 VDC as measured at
terminals 10 (–) and 11 (+) on the governor controller.
Disconnect the actuator lead connected at governor
controller terminal 5 and connect it to the negative (–)
terminal of the cranking battery. Then disconnect the
lead connected at terminal 4 and touch it to the battery
positive (+) terminal. Replace the actuator unit if it
does not drive the linkage through its full travel when
power is connected or return it when power is disconnected.
Replace the governor controller if it still cannot be adjusted for full power or stable speed.
The engine fuel system (lift pump, injection pump, injectors, timing) is faulty.
Service the fuel system according to the engine service manual.
The engine is worn.
Service the engine according to the engine service
manual.
4-10
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
AMBER WARNING LAMP ON
The PRE-LOW OIL PRESSURE lamp
comes on while the engine is running.
Shut down the set if possible or disconnect non-critical
loads.(Oil pressure will be less than 20 psi [138kPa]
but greater than 14 psi [97 kPa].) Service the engine
lubricating system according to the engine service
manual. Normal operating range is 35 to 60 psi (241 to
414 kPa).
The PRE-HIGH ENGINE TEMPERATURE lamp comes on while the engine is
running.
Shut down the set if possible or disconnect non-critical
loads. Engine temperature will be greater than 220° F
(104° C) but less than 230° F (110° C). Service the engine cooling system to restore full cooling capacity.
The LOW ENGINE TEMPERATURE
lamp comes on while the set is in standby.
Plug in, repair or install engine coolant and engine oil
heaters.
The LOW FUEL lamp comes on.
Fill the main fuel supply tank with the appropriate
grade of fuel. (The customer has supplied the fuel level
switch to make use of this warning.)
FAULT 1 or FAULT 2 (RED)
Service as required. (The customer has supplied the
system fault indicating switches. By means of selection jumpers, either fault may be chosen to shut down
the engine. See See Section 3, Engine Control.
4-11
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE GREEN RUN LAMPS STAY OFF BUT THE SET RUNS NORMALLY
The set mounted RUN lamp does not light
although the starter has disconnected
normally and the engine is running
Press the panel Lamp Test switch and replace the run
lamp bulb if it does not light.
If the lamp is good, this indicates that the DC disconnect circuit (K14 relay circuit on the ECM) is not working. Check the DC voltmeter and if there is not at least
12 volts, check for loose or missing wiring between the
battery charging alternator and terminal TB1-2 and pin
connector P1-3 on the ECM. See Page 7-6 or 7-8 regarding the applicable alternator configuration. If the
connections are good, replace the battery charging alternator.
If the RUN lamp, wiring connections and battery
charging alternator are all good and the RUN lamp
does not light during normal operation, replace the
ECM.
Neither the remote nor the set mounted
RUN lamp light although the starter has
disconnected normally and the engine is
running.
Press the panel Lamp Test switch and replace the run
lamp bulb if it does not light. Test the remote RUN lamp
by suitable means and replace it if it does not light.
If both lamps are good, this indicates that the AC disconnect circuit (K10 relay circuit on the ECM) is not
working. Check the AC voltmeter to determine whether or not there is generator output voltage and service
as necessary. See There Is No Output Voltage.
If there is generator output voltage, check for 120 VAC
across pin connectors P1-1 and P1-2 on the ECM. If
there is no voltage, check for loose or missing leads
between the connectors and TB21-21 and TB21-32
inside the control box and service as necessary.
Replace the ECM if there is 120 VAC across pin connectors P1-1 and P1-2 but neither RUN lamp lights
during normal operation.
4-12
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THERE IS NO OUTPUT VOLTAGE (ENGINE SPEED IS STABLE)
The line circuit breaker is OFF.
Find out why the circuit breaker was turned OFF, make
sure it is safe to reconnect power, and then throw the
circuit breaker ON.
The line circuit breaker has TRIPPED.
Shut down the set and service as necessary to clear
the short circuit or ground fault that caused tripping,
and then RESET the circuit breaker and start the set.
Shut down the set, make sure the power output lines
from the set have been disconnected from all other
sources of power, attempt to RESET the circuit breaker and throw it ON and check for electrical continuity
across each line contact. Replace the circuit breaker if
there is measurable resistance across any contact.
The line circuit breaker is faulty.
Field circuit breaker CB21 has TRIPPED.
RESET the circuit breaker. If it keeps tripping, troubleshoot according to the chart, Field Circuit Breaker
Keeps Tripping.
Field circuit breaker CB21 is faulty.
Shut down the set, attempt to RESET the circuit breaker and disconnect either lead. Replace the circuit
breaker if there is measurable resistance across the
terminals.
Continued on next page.
4-13
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THERE IS NO OUTPUT VOLTAGE (CONT. )
Continued from previous page.
Determine, as follows, whether the fault is in the VOLTAGE REGULATING or GENERATOR circuits:
1. Throw the line circuit breaker OFF and shut down the set.
CAUTION This test involves unregulated excitation of the generator. To prevent damage to the generator due to overcurrent, make sure that all loads have been disconnected and that all faults have been
cleared from the power output terminals of the generator.
2. Open the control panel and disconnect the F1 (+) and the F2 (–) leads from the voltage regulator. See Figure 2-2.
HIGH VOLTAGE. Touching uninsulated high voltage parts inside the control box can result in
severe personal injury or death. Measurements and adjustments must be done with care to avoid touching high voltage parts.
For your protection, stand on a dry wooden platform or rubber insulating mat, make sure your clothing
and shoes are dry, remove jewelry from your hands and wear elbow length insulating gloves.
3. Start the set and check for output voltage at the main stator terminals.
a. Is there 5–20 VAC residual voltage at the output of the main stator windings when the exciter leads are disconnected?
• YES: The main stator windings are good, continue with step 4.
• NO: Use the GENERATOR FAULT chart to troubleshoot generator.
4. If the residual voltage is good, stop the set and reconnect the exciter leads to the exciter stator. Start the set. Has
the output voltage increased?
• YES: Adjust the Coarse Voltage Adjust pot on VRAS-2.
• NO: Check if CB21 is closed. If CB21 is OK, flash the field using the procedure in Section 5.
5. When field is flashed, does the output voltage from the main stator increase?
• YES: The generator assembly is OK.
• NO: Use the GENERATOR FAULT chart to troubleshoot generator.
6. If the output voltage increased when the field was flashed, does the output voltage remain after the flash circuit is
removed?
• YES: The generator assembly and VRAS-2 are OK.
• NO: VRAS-2 is defective. Use the VOLTAGE REGULATING FAULTS chart to troubleshoot VRAS-2.
7. Put a full load on the generator set. Does the generator set output stay up after the generator set has responded to
the load?
• YES: The generator assembly and VRAS-2 are OK.
• NO: Check each diode according to Section 5, Servicing the Generator.
Continued on next page.
4-14
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THERE IS NO OUTPUT VOLTAGE (CONT. )
Continued from previous page.
VRAS-2 FAULTS
Flash the field according to Section 5, Servicing the
Generator.
The field has lost its residual magnetism.
Check all connections against the wiring diagrams on
pages 7-2 and 7-9 and rewire as necessary. Replace
VRAS-2 if the wiring is correct and there is no output
voltage.
Voltage Regulator VRAS-2 is faulty.
CAUTION Replacing VRAS-2 before servicing
other faults can lead to damage to the new VRAS-2.
Continued on next page.
4-15
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THERE IS NO OUTPUT VOLTAGE (CONT. )
Continued from previous page.
GENERATOR FAULTS
The exciter field winding is faulty (open or
shorted).
Shut down the set and check exciter field winding resistance according to Section 5, Servicing the Generator. Replace the exciter field assembly if winding resistance does not meet specifications.
The rotating rectifier assembly (diodes
CR1 through CR6) is faulty.
Shut down the set and check each diode according to
Section 5, Servicing the Generator. Service as necessary.
The exciter rotor windings are faulty
(open or shorted).
Shut down the set and check exciter winding resistances according to Section 5, Servicing the Generator. Replace the generator rotor assembly if exciter rotor winding resistances do not meet specifications.
The main rotor winding is faulty (open or
shorted).
Shut down the set and check main rotor winding resistance according to Section 5, Servicing the Generator.
Replace the generator rotor assembly if main rotor
winding resistance does not meet specifications.
The stator windings are faulty (open or
shorted).
Shut down the set and check stator winding resistances according to Section 5, Servicing the Generator.
Replace the generator stator assembly if stator winding resistances do not meet specifications.
4-16
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
OUTPUT VOLTAGE IS TOO HIGH OR TOO LOW
Adjust engine speed according to Section 6, Governors.
Engine speed is too high or too low.
If engine speed is unstable, troubleshoot according to
the chart, The Engine Lacks Power or Stable Speed.
Adjust output voltage according to Section 2, AC Control.
The voltage has been adjusted improperly.
Shut down the set and reconnect according to the reconnection diagram on page 7-9.
Improper connections have been made at
the generator output terminals.
Shut down the set and check each diode according to
Section 5, Servicing the Generator. Service as necessary.
The rotating rectifier assembly (diodes
CR1 through CR6) is faulty.
Replace the voltage regulator.
CAUTION Replacing VRAS-2 before servicing
other faults can lead to damage to the new VRAS-2.
Voltage Regulator VR21 is faulty.
4-17
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
OUTPUT VOLTAGE IS UNSTABLE
The voltage has been adjusted improperly.
Adjust output voltage according to Section 2, AC Control.
The voltage adjusting rheostat on the
control panel is faulty (if provided).
Unlock the voltage adjusting screw on the front of the
control panel and disconnect either lead from the rheostat. Measure resistance between terminals 1 and 2
while turning the adjusting screw fully one way and
then the other. Replace the rheostat if it is open at any
point, or if resistance does not vary smoothly from zero
to approximately 1,500 ohms.
Replace the voltage regulator.
Voltage Regulator VR21 is faulty.
CAUTION Replacing VRAS-2 before servicing
other faults can lead to damage to the new VRAS-2.
4-18
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE FIELD CIRCUIT BREAKER KEEPS TRIPPING
The rotating rectifier assembly (diodes
CR1 through CR6) is faulty.
Shut down the set and check each diode according to
Section 5, Servicing the Generator. Service as necessary.
The exciter field winding is shorted.
Shut down the set and check exciter field winding resistance according to Section 5, Servicing the Generator. Replace the exciter field assembly if winding resistance does not meet specifications.
The exciter rotor windings are shorted.
Shut down the set and check exciter winding resistances according to Section 5, Servicing the Generator. Replace the generator rotor assembly if exciter rotor winding resistances do not meet specifications.
The main rotor winding is shorted.
Shut down the set and check main rotor winding resistance according to Section 5, Servicing the Generator.
Replace the generator rotor assembly if main rotor
winding resistance does not meet specifications.
The stator windings are shorted.
Shut down the set and check stator winding resistances according to Section 5, Servicing the Generator.
Replace the generator stator assembly if stator winding resistances do not meet specifications.
Replace the voltage regulator.
Voltage Regulator VR21 is faulty.
CAUTION Replacing VRAS-2 before servicing
other faults can lead to damage to the new VRAS-2.
4-19
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WARNING Hazards present in troubleshooting can cause equipment damage, severe personal injury
or death. Troubleshooting must be performed by qualified persons who know about fuel, electrical
and machinery hazards. Read the Safety Precautions page and carefully observe all instructions and
precautions in this manual.
THE PHASE CURRENTS ARE UNBALANCED
The connected loads are distributed unevenly among the phases.
Shut down the set and redistribute the loads so that
there is a difference of less than 10 percent between
phases.
Improper connections have been made at
the generator output terminals.
Shut down the set and reconnect according to the reconnection diagram on page 7-9.
The stator windings are faulty (open or
shorted).
Shut down the set and check stator winding resistances according to Section 5, Servicing the Generator.
Replace the generator stator assembly if stator winding resistances do not meet specifications.
A load has a ground fault or short circuit.
Service the faulty equipment as necessary.
4-20
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5. Servicing the Generator
Make certain battery area has been well-ventilated before servicing battery. Arcing can ignite
explosive hydrogen gas given off by batteries,
causing severe personal injury. Arcing can occur when cable is removed or re-attached, or
when negative (–) battery cable is connected
and a tool used to connect or disconnect positive (+) battery cable touches frame or other
grounded metal part of the set. Always remove
negative (–) cable first, and reconnect it last.
Make certain hydrogen from battery, engine
fuel, and other explosive fumes are fully dissipated. This is especially important if battery has
been connected to battery charger.
TESTING THE GENERATOR
These tests can be performed without removing the
generator. Before starting tests, turn off or remove
AC power from the battery charger and then disconnect the starting battery cables (negative [-] first) to
make sure the engine will not start while performing
these tests.
CAUTION Always disconnect a battery charger from its AC source before disconnecting the
battery cables. Otherwise, disconnecting the
cables can result in voltage spikes high enough
to damage the DC control circuits of the set.
WARNING Accidental starting of the generator
set while working on it can cause severe personal injury or death. Prevent accidental starting by disconnecting the starting battery cables
(negative [–] first).
BLOWER
MAIN
STATOR
PMG
ASSEMBLY
EXCITER
STATOR
ROTATING
RECTIFIER
ASSEMBLY
OVERSPEED
SWITCH
END
BEARING
EXCITER
ROTOR
DRIVE
DISCS
SCREEN
MAIN ROTOR
(GENERATOR FIELD)
FIGURE 5-1. GENERATOR
5-1
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INSULATION RESISTANCE (MEGGER) &
POLARIZATION INDEX (PI) TESTING
If moisture is determined to be the cause of low test
readings, a winding drying process will be required.
These tests are used for insulation testing and to
verify that the windings are dry before the generator
set is operated and develop a base line for future
test comparison.
DRYING THE WINDINGS
If low readings are obtained and moisture is determined to be the problem, the windings should be
dried out and the test repeated. Use the generator
heaters or blow warm air through the generator with
a fan. A more effective way is to use a bolted 2 /
3-phase short across the generator terminals. This
procedure must be done as described or equipment
damage can result. To do this:
Megger Testing
A 500 VDC megger is recommended for insulation
testing. A test consists of applying the voltage between the winding and ground for one minute.
1. Bolt the two or the three phases of the generator together at the terminals. See the reconnection diagram in Section 7.
2. Disconnect the F1 and F2 leads (Figure 5-2) at
the voltage regulator and connect them to a
variable 12 VDC source. Positive lead to F1,
negative lead to F2.
3. Attach a clamp-on ammeter to the generator
leads to measure generator current, adjust the
12 VDC source for zero volts, start the set and
slowly increase the excitation voltage. Obtain
the highest current possible without exceeding
generator rating.
4. Run the set for approximately one hour and repeat the insulation resistance tests. If further
drying time is indicated, continue the drying
process.
Resistance value of at least 5 megohms should be
obtained for a new generator with dry windings. For
a set that has been in service, the resistance reading should not be less than 1 megohm.
PI Testing
The PI test consists of applying a voltage between
the winding and ground for ten minutes and recording resistance values at one minute and at ten minutes. The PI is the ratio of a ten minute reading in
megohms divided by a one minute reading in megohms. A ratio of two or greater is considered good
for new and in service sets.
If low readings are obtained, the cause should be investigated and corrected before the generator set is
returned to service.
5-2
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EXCITER STATOR
Testing Winding Insulation Resistance
Testing Winding Resistance
Disconnect the F1 and F2 exciter stator leads at the
voltage regulator and isolate them from ground.
Measure winding resistance with a Wheatstone
bridge or digital ohmmeter. Resistance should be
approximately 20 ohms at 68° F (20° C).
Connect the megger between one of the leads and
ground and conduct the test. Replace the stator if
insulation resistance is less than 1 megohm
(1,000,000 ohms).
Before performing the following insulation resistance test, refer to the Insulation Resistance and Polarization Index Test procedure at the beginning of
this section.
MEASURE WINDING
INSULATION RESISTANCE
BETWEEN EITHER LEAD
AND THE STATOR
LAMINATIONS
MEASURE WINDING
RESISTANCE BETWEEN
THE TWO STATOR
LEADS, F1 AND F2
FIGURE 5-2. TESTING AND FLASHING THE EXCITER STATOR
5-3
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With Generator Set in Operation:
Flashing the Field
CAUTION
This test involves unregulated excitation of the generator. To prevent damage to
the generator due to overcurrent, make sure
that all loads have been disconnected and that
all faults have been cleared from the power output terminals of the generator.
1. Start the generator set.
2. Touch the positive battery lead to TB1-9 and
the negative lead to TB1-10 of VRAS-2. Hold
the leads in place just long enough for the voltage to build up to the normal operating level,
then remove the leads.
3. Check generator voltage, and shut down generator set. Restart generator set and run at no
load. Unit must build up voltage without field
flashing. If not, shut down generator set and
perform continuity check of all related wiring.
With Generator Set Shut Down:
1. Touch the positive battery lead to TB1-9 and
the negative lead to TB1-10 of VRAS-2.
2. Hold the leads in place for no longer than 5 seconds.
3. Start generator and run at no load. Unit must
build up voltage without field flashing. If it does
not, shut down generator set and perform continuity check of all related wiring.
If output voltage does not build up, it may be necessary to restore residual magnetism by flashing the
field. This requires a 12-volt battery, a 12-ampere
300-volt diode, and a 12-volt light bulb or a 2-watt
20-ohm resistor wired as shown in Figure 5-3.
Flashing the field can be accomplished with generator set operating or not. Either of the following procedures should be sufficient to restore residual
magnetism.
CAUTION Incorrect field flashing procedures
can damage regulator or exciter stator windings. Do not maintain field flash connection to
exciter circuit longer than 5 seconds.
Make sure a diode is used in the field flash apparatus to prevent the regulator from overcharging the battery. Batteries can explode when
overcharged.
EXCITER
STATOR
MAIN STATOR
12-AMPERE,
300-VOLT DIODE
(–)
L1
L3
10
AVR
(+)
9
REFERENCE
VOLTAGE
L0
L2
(–)
12-VOLT LIGHT BULB OR
2-WATT 20-OHM RESISTOR
(+)
12-VOLT
BATTERY
FIGURE 5-3. FIELD FLASHING CIRCUIT
5-4
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each diode should be high in one direction
and low in the other. If the resistance is
high or low in both directions, replace the
diode.
EXCITER RECTIFIER BRIDGE (ROTATING
RECTIFIER ASSEMBLY)
The exciter rectifier bridge is mounted on the exciter
rotor, outboard, facing the rear. It consists of a positive plate and a negative plate, each carrying three
diodes.
3. To replace diodes, use the following procedure.
A. Unsolder lead wires of defective diodes
from flag terminals.
CAUTION
Layers of dust can cause diodes to
overheat and fail. Brush dust off regularly.
B. Insert new diode into heatsink mounting
hole. Using nut and washer provided, secure diode to heatsink.
1. Disconnect one diode at a time by removing
diode from heatsink.
A. Use proper size wrenches to hold the
diode body while removing the nut.
B. Push the diode free of the heatsink mounting hole.
2. Test that diode before proceeding to the next
one.
A. Using an ohmmeter, measure electrical
resistance between the flag and the stud
of the diode.
B. Reverse the meter test probes and repeat
the tests. The electrical resistance across
C. Use proper size wrenches to hold the
diode body while tightening the nut.
Torque diodes on rotating exciter assembly to 24 in-lbs (2.7 N•m).
D. Solder lead wires to new diode flag terminals.
CAUTION
Excessive heat on these diodes
will destroy them. Use a 40 watt soldering
iron. Hold a needlenose pliers between
diode and soldering point to prevent destructive heating.
REMOVE DIODE (1 OF
6) FROM HEATSINK AND
MEASURE ELECTRICAL
RESISTANCE BETWEEN
THE PIGTAIL AND THE
METAL PLATE UNDER
THE DIODE
DIODE
HEATSINKS
FIGURE 5-4. TESTING THE ROTATING RECTIFIER ASSEMBLY
5-5
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EXCITER ROTOR
Testing Winding Insulation Resistance:
Testing Winding Resistance:
Remove diodes CR1 through CR6 from diode heat
sink assemblies. Using a megger (voltage set at
500 VDC), measure the resistance between any rotor winding lead or the terminal to which it is connected and the rotor laminations. Replace the exciter rotor if insulation resistance is less than 1 megohm.
Remove diodes CR1 through CR6 from diode heat
sink assemblies. With a Wheatstone bridge, measure electrical resistance across each pair of rotor
windings: T1 (CR1 or CR4) and T2 (CR2 or CR5),
T2 (CR2 or CR5) and T3 (CR3 or CR6), T3 (CR3 or
CR6) and T1 (CR1 or CR4). See the winding schematic. Resistance should be 0.464 to 0.567 ohms at
68° F (20° C).
MEASURE WINDING
INSULATION RESISTANCE
BETWEEN ANY LEAD OR
THE TERMINAL TO WHICH
IT IS CONNECTED AND
THE ROTOR LAMINATIONS
WINDING SCHEMATIC
T11
REMOVE DIODES CR1 THROUGH
CR6 FROM DIODE HEAT SINK
ASSEMBLIES AND MEASURE
ELECTRICAL RESISTANCE
ACROSS EACH PAIR OF
WINDINGS: T1-T2, T2-T3, T3-T1
T21
T1
T2
T23
T13
T3
T12
T22
FIGURE 5-5. TESTING THE EXCITER ROTOR
5-6
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Before performing the following insulation resistance test, refer to the Insulation Resistance and Polarization Index Test procedure at the beginning of
this section.
MAIN ROTOR (GENERATOR FIELD)
Testing Winding Resistance
Disconnect the two leads of the main rotor from the
terminals on the rotating rectifier assembly. See
Figure 5-6. Measure electrical resistance between
the two leads with a Wheatstone bridge or digital
ohmmeter. Replace the rotor if the resistance is not
as shown in the following list. Connect the rotor
leads and torque the terminals to 24 in-lbs (2.7
N•m) when reassembling.
Insulation Resistance and PI Test
Disconnect the two leads of the main rotor from the
terminals on the rotating rectifier assembly. Using a
megger (voltage set at 500 VDC), measure the resistance between either lead of the main rotor windings, or the terminal to which it is connected, and the
main rotor laminations. Replace the rotor if insulation resistance is less than 1 megohm.
• EK – 3.32 to 4.06 ohms at 68° F (20° C)
• EM – 2.49 to 3.05 ohms at 68° F (20° C)
MEASURE WINDING INSULATION
RESISTANCE BETWEEN EITHER
ROTOR LEAD AND THE ROTOR
LAMMINATIONS
DISCONNECT THE MAIN ROTOR LEADS
FROM THE ROTATING RECTIFIER
ASSEMBLY AND MEASURE THE
WINDING RESISTANCE BETWEEN THEM
FIGURE 5-6. TESTING THE MAIN ROTOR
5-7
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ries). On a “series star” connected generator, lineto-line resistance should be four times the table value (four winding elements in series). On a “parallel
star” connected generator, line-to-line resistance
should be the same as the table value (two sets of
two winding elements in series).
MAIN STATOR
Testing Winding Resistance
Disconnect all stator leads from the terminals to
which they are connected. Using a Wheatstone
bridge or ohmmeter having at least 0.001 ohm precision, measure electrical resistance across each
pair of stator leads (T1-T4, T7-T10, T2-T5, T8-T11,
T3-T6, T9-T12). Replace the stator if the resistance
of any winding is not as specified in Table 5-1.
Before performing the following insulation resistance test, refer to the Insulation Resistance and Polarization Index Test procedure at the beginning of
this section.
Insulation Resistance and PI Test
TABLE 5-1. STATOR RESISTANCE VALUES*
Disconnect all stator leads and winding taps from
their respective terminals and make sure the ends
do not touch the generator frame.
VOLTAGE CODE
MODEL
EK
EM
L, R, 15, & 32
H & 9X
E & 6D
0.116-0.141
0.047-0.058
0.425-0.520
0.193-0.236
0.432-0.528
0.202-0.248
Testing For Grounds: Using a megger (voltage set
at 500 VDC), measure electrical resistance between any stator lead and the stator laminations.
Replace the stator if insulation resistance is less
than 1 megohm.
* These values are approximate, plus or minus
10 percent at 68° F (20° C).
Testing for Shorts: Using a megger (voltage set at
500 VDC) measure electrical resistance between
each winding, for example T1/T4 to T7/T10, T1/T4
to T2/T5, etc. Replace the stator if insulation resistance is less than 1 megohm.
Alternatively, winding resistance can be measured
line-to-line at the generator terminals (L1-L2,
L2-L3, L3-L1) on “star” connected generators. On a
600 volt generator, line-to-line resistance should be
twice the table value (two winding elements in se-
MEGGER OR
INSULATION
RESISTANCE
METER
WHEATSTONE
BRIDGE
FIGURE 5-7. TESTING THE GENERATOR STATOR
5-8
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8. Disconnect the line cables and conduit. For reconnections later, make sure each cable is
clearly marked to indicate the correct terminal.
REMOVING AND DISASSEMBLING THE
GENERATOR
The generator is heavy. You will need an assistant
and a hoist of sufficient capacity to remove and service the generator.
9. Disconnect the remote control wiring and conduit. For reconnections later, make sure each
wire is clearly marked to indicate the correct
terminal.
WARNING Accidentally dropping the generator can damage it and cause severe personal injury and death. The hoist, straps and chains
must have sufficient capacity and be attached
properly so that the load cannot shift.
10. Disconnect all engine wiring harness connections in the generator control and output boxes.
For reconnections later, make sure each wire is
clearly marked to indicate the correct terminal.
Before starting, disconnect the starting battery
cables (negative (-) first) to make sure the set will
not start while working on it.
11. Disconnect all generator control leads (winding
taps) from connections in the output box. For
reconnections later, make sure each wire is
clearly marked to indicate the correct terminal.
WARNING Accidental starting of the generator
set while working on it can cause severe injury
or death. Prevent accidental starting by disconnecting the starting battery cables (negative (-)
first).
12. If the set has a mounted line circuit breaker, disconnect the cables to the circuit breaker. For
reconnections later, make sure each cable is
clearly marked to indicate the correct terminal.
Always remove the negative (-) cable first, and
reconnect it last, to prevent arcing if a tool accidentally touches the frame or other grounded
metal part while removing the positive (+) battery cable. Arcing can ignite the explosive hydrogen gas given off by the batteries, causing
severe injury.
13. Remove the sheet metal from around the generator.
14. Remove the overspeed switch and bracket
from the end bell and rotor shaft. See Figure
5-8.
ADJUST
SCREW
GENERATOR
SHAFT
AIR GAP (NOT LESS
THAN 0.005 IN. [13 MM]
SWITCH
CONTACTS
END
BELL
FIGURE 5-8. OVERSPEED SWITCH ASSEMBLY
5-9
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the placement bolts to 200 to 240 ft-lbs (271 to
325 N•m).
5. Using a hoist and sling to support the rotor,
align the holes in the drive disk and fan with the
corresponding holes in the flywheel.
6. Install the bolts that hold the drive disk to the
engine flywheel and torque to 55 to 60 ft-lbs (75
to 81 N•m).
15. Block the rear of the engine in place by supporting the flywheel housing.
16. Remove the four nuts and washers from the
studs that secure the end bell.
17. Remove end bell with oil seal from stator assembly. It might be necessary to tap around
end bell joint to separate end bell from stator.
18. Remove the four 1/4-inch bolts and lock washers securing the exciter stator to the end bell.
19. Remove the narrow generator air screen.
20. Remove the large capscrews securing the
generator to the skid base.
21. Remove the bolts securing the stator to engine
flywheel housing.
22. Using an overhead hoist and sling, slide the
stator assembly off the long through-studs
(note position of hose pieces on the studs, and
proper orientation of the stator) being careful
not to touch or drag on the rotor.
The studs can be removed if you want to do so.
CAUTION Do not allow the rotor to hang
unsupported for any extended period.
Otherwise, drive disk damage can occur.
7. Using a hoist and safe lifting device, carefully
move the stator into position over the rotor assembly. The stator leads should be at the 12
o’clock position when viewed from the end bell
position. Make sure the short hose pieces are
in place next to the flywheel housing before
installing stator.
8. Align the holes of the stator with the engine flywheel housing and install the bolts. Torque to
35 ft-lbs (47 N•m).
9. Install the exciter stator in the end bell using the
1/4-inch bolts and lock washers. Torque to 7 ftlb (9 N•m).
10. Apply a thin film of Molykote grease or equivalent to the mating surfaces of the end bearing
and end bell bearing hole.
11. Install the end bell assembly, lock washers,
and nuts on the studs. Torque nuts to 35 ft-lbs
(47 N•m).
12. Using a lead hammer, tap the end bell at the
horizontal and vertical plane to relieve stress.
Retorque end bell stud nuts.
13. Install the generator air screen.
14. Refer to Figure 5-8. Mount and adjust Mechanical Overspeed Switch.
When installing the overspeed switch assembly (capscrew, lock washer, switch, small flat
washers, large flat washer, and spacer) on the
rotor shaft, torque to 53 ft-lbs (72 N•m).
Install the overspeed switch assembly bracket
and secure using two capscrews and lock
washers. Torque to 4.5 ft-lb (6 N•m). Refer to
Figure 5-9, and set to proper gap
Connect overspeed switch lead wire to terminal on overspeed switch bracket.
15. Install the control sheet metal back on the generator.
16. Reconnect the generator as required.
CAUTION Do not allow the rotor to hang
unsupported for any extended period.
Otherwise, drive disk damage can occur.
23. Attach the hoist and sling to the rotor assembly
and apply a slight lift to support the rotor. Remove the bolts securing the drive disk to the engine flywheel and remove the rotor from the engine. Set on wood blocks so fan is not supporting any of the rotor weight.
24. Remove bearing bolt, flat washer, and lock
washer. Then remove bearing. If required, remove fan from the rotor.
25. Disconnect rotor field leads from heat sinks F1
and F2 on the exciter rotor. Remove exciter rotor.
REASSEMBLING THE GENERATOR
1. If any diodes are replaced in the exciter rotor,
secure the new diode using a lock washer and
nut, and torque to 12 to 15 in-lbs (1.4 to 1.7
N•m).
2. Slide exciter rotor, sleeve spacer, and press
ball bearing over the generator shaft. Install the
modified hex head bolt, lock washer, and flat
washer and torque to 60 to 70 ft-lbs (81 to 95
N•m).
3. Place the generator fan in position on the rotor
shaft.
4. Install the drive disk on the end of the rotor shaft
with the chamfer on the flywheel side. Torque
5-10
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DISK-TO-ROTOR
BOLT
DISK
GENERATOR
FAN
DISK-TO-FLYWHEEL
BOLT
ROTOR
EXCITER
ROTOR
MODIFIED HEX
HEAD BOLT
OVERSPEED
SWITCH
STATOR-TO-FLYWHEEL
HOUSING BOLT
SLEEVE
SPACER
BALL
BEARING
EXCITER-TO-END
BELL BOLT
GENERATOR
STATOR
OVERSPEED
CONTACT
ASSEMBLY
GENERATOR
AIR SCREEN
EXCITER
STATOR
O-RING
OIL SEAL
END
BELL
STUD
FIGURE 5-9. GENERATOR ASSEMBLY
5-11
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6. Governors and Carburetors
2. Start the set, let the engine warm up under a
partial load (at least 1/4 rated load) and then disconnect all loads. (If the governor has been replaced, adjust the Gain 1 and Stability 1 pots to
their center settings.)
ELECTRIC GOVERNOR ADJUSTMENT
If necessary, adjust the gas mixture, the governor
linkage and the magnetic speed pickup unit as
instructed in this section before adjusting the governor controller. Make sure that the governor assembly is securely mounted. Also make sure that the
governor linkage does not bind or have excessive
play in it.
3. Adjust the Gain 1 pot until the engine is stable
and responsive to governor control. (Adjust the
Gain 1 pot counterclockwise to eliminate hunting.) Bump the throttle lever a couple of times to
check for hunting. The unit should respond
quickly but should not hunt.
1. Check the dip switch settings (Figure 6-1) to
make sure they are set properly, as follows:
4. Apply full load to the genset and adjust the Stability 1 pot to minimize overshoot. (Adjust the
Stability 1 pot clockwise to increase stability.)
Check stability under a range of loads; from noload to full-load.
IGNITION TRIGGER (GOV MOD A378)
50 Hz
60 Hz
SW1
(8CYL)
SW2
(6CYL)
OFF
OFF
ON
ON
SW3
SW4
(4CYL) (50/60HZ)
OFF
OFF
OFF
ON
SW1
SW2
SW3
SW4
5. Attach a tachometer or frequency meter to the
generator output leads if control panel does not
come equipped with one of these meters. Adjust the Speed Trim pot until the desired speed
is obtained.
ON
ON
OFF
OFF
OFF
OFF
OFF
ON
6. Shut down and restart the genset to check for
overspeed shutdown on startup.
MPU TRIGGER (GOV MOD A377)
50 Hz
60 Hz
GAIN 1
GOVERNOR CONTROLLER
CONNECTIONS – SEE
FIGURE 6-3
STABILITY 1
SPEED TRIM
SW1
SW2
SW3
SW4
ON POSITION
DIP
SWITCHES
FIGURE 6-1. GOVERNOR CONTROLLER
6-1
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2. Verify that the ball joint screw is mounted in the
third hole from the outside end of the governor
arm.
LINKAGE ADJUSTMENT
Figure 6-2 illustrates the governor linkage. Make
sure that the governor controller is securely
mounted to the engine bracket. To adjust the linkage:
3. The governor actuator shaft has 60 degrees of
rotation from stop to stop. Check mounting of
governor arm and linkage to assure the 60 degree actuator shaft rotation operates the throttle
from closed to fully open positions.
1. With the genset stopped, check the angle of the
throttle lever and governor actuator. Adjust governor lever if required. (Throttle is shown in the
closed position.)
BALL JOINT
SCREW
BALL JOINT
SCREW
GASEOUS
CARB
GOVERNOR ROD DETAILS
(SHOWN IN THROTTLE
CLOSED POSITION)
GASOLINE
CARB
THROTTLE
LEVER
GOVERNOR ARM
OUTSIDE END
GOVERNOR
ROD
FIGURE 6-2. GOVERNOR LINKAGE
6-2
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lines up in the center of the mounting hole. Thread
the pickup in gently by hand until it just touches the
ring gear tooth. Back it out 5/8 turn and set the locknut.
MAGNETIC SPEED PICKUP UNIT
ADJUSTMENT
With the magnetic speed pickup removed from the
genset, manually rotate the ring gear until a tooth
TO GOVERNOR
CONTROLLER
MAGNETIC SPEED
PICKUP UNIT
MPU TYPE
GENERATOR
ADAPTER
TO GOVERNOR
CONTROLLER
IGNITION
TYPE
FIGURE 6-3. MAGNETIC SPEED PICKUP UNIT / GOVERNOR CONTROLLER CONNECTIONS
6-3
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CAUTION The adjustment screw and seat
are easily damaged. Do not force the adjustment screw.
CARBURETORS
The engine is equipped with a carburetor to run on
regular gasoline and/or a gas mixer to run on natural gas or propane or both.
2. Start the engine and let the set warm up under
a partial load (at least 1/4 rated load) and then
disconnect all loads.
WARNING Fuel is highly flammable and may
cause severe personal injury and property damage. Do not allow cigarettes, flame, pilot lights,
arcing switches or equipment in area or areas
sharing ventilation.
3. Turn the idle adjustment screw out (counterclockwise) approximately one half turn and
jounce the throttle. If the engine begins to hunt,
turn the adjustment screw in slowly until engine
speed becomes stable. If one half turn does not
cause instability, turn the adjustment screw out
one half turn more and repeat the procedure.
Gasoline Fuel System
A gasoline carburetor (Figure 6-4) is provided for
gasoline fuel systems. The main and idle mixture,
and choke are adjustable on the gasoline carburetor. The main adjusting needle, at the bottom of the
carburetor, affects operation at heavier load conditions. the idle adjusting needle, at the side of the
carburetor, affects operation at light and no load
conditions.
Main Mixture Adjustment: If the adjustment has
been disturbed or the engine performs poorly under
heavy load, make the following adjustments.
1. Shut off the engine and turn the main adjustment screw in gently until it bottoms, and then
turn it out 1 turn so that the engine will run.
Under normal circumstances, factory carburetor
adjustments should not be disturbed. If adjustments
have been changed, an approximate setting of
1-1/2 turn open for idle needle and one turn open for
main needle will permit starting. Adjust temporarily
for smoothest running. Allow engine to thoroughly
warm up before making final adjustment.
2. Start the engine and let the set warm up under
a partial load (at least 1/4 rated load) and then
apply a full load.
3. Slowly turn needle out until speed no longer
rises. Try various electrical loads. If engine
speed fluctuates at any load, turn main adjusting needle out slightly. Do not turn out more
than 1/2 turn beyond original full load setting.
Idle Mixture Adjustment: If the adjustment has
been disturbed or the engine performs poorly under
light load, make the following adjustments.
4. If stable speed cannot be obtained by adjusting
main adjusting needle, a change in governor
sensitivity adjustment will probably be necessary.
1. Shut off the engine and turn the idle adjustment
screw in gently until it bottoms, and then turn it
out 1-1/2 turns so that the engine will run.
6-4
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IDLE ADJUSTMENT
SCREW
BOWL
DRAIN
PLUG
MAIN
ADJUSTMENT
FIGURE 6-4. GASOLINE CARBURETOR
6-5
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Choke Adjustment for Gasoline carburetor: The
gasoline carburetor is equipped with an automatic
choke for easier cold weather starting. The choke
has a bi-metal coil that progressively closes the
choke plate as ambient temperature drops, in preparation for the next start. It also has an electric heating element that heats the bi-metal coil to fully open
the choke soon after the engine starts.
LONG
RAISED
LINE
”ASTERISK“
MARK
The choke housing cover can be rotated to adjust
the choke. The perimeter of the cover is graduated
with evenly spaced lines cast in it. One of the lines
has an asterisk (*). For normal adjustments, the asterisk (*) should line up with the line cast in the edge
of the housing.
1. For better starting in cold weather, loosen the
three cover screws (Figure 6-5) and rotate the
cover clockwise (richer) so that the asterisk (*)
is one or two lines past the line on the housing
and re-tighten the cover screws.
2. For better starting in warm weather, loosen the
three cover screws and rotate the cover counterclockwise (leaner) so that the asterisk (*) is
one or two lines past the line on the housing
and re-tighten the cover screws.
LOCKING
SCREWS (3)
FIGURE 6-5. ELECTRIC CHOKE
6-6
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varying load conditions (approximately 5 inches
WC for natural gas and –1.5 inches WC for LPG).
There is a pressure test port on the supply side if the
gas mixer for measuring fuel inlet pressure.
Gaseous and Combination Fuel Systems
An engine equipped for gasoline and natural gas or
propane has a regular gasoline carburetor with a
gas mixer mounted on the horn of the carburetor.
The carburetor throttle serves both fuels. Each fuel
has a separate shutoff solenoid valve. The position
of the fuel selector switch (mounted at the base of
the carburetor) determines which solenoid valve
will open for operation.
The maximum permissible fuel supply pressure
is 20 inches WC and the minimum is 7 inches
WC. This applies to LPG as well as to natural gas.
The minimum pressure refers to supply pressure
under rated load (maximum gas flow). There is a
pressure test port on the supply side of each fuel
regulator for measuring fuel supply pressure.
An engine equipped for natural gas and propane
has a gas mixer that serves both fuels. Each fuel
has a separate shutoff solenoid valve and either a
manual fuel selector switch or a fuel pressure
switch for automatic fuel changeover. (While the engine is running, the gas pressure switch causes the
natural gas solenoid valve to close and the propane
solenoid valve to open when natural gas pressure is
lost, without stopping the engine. When natural gas
pressure is restored, the natural gas solenoid valve
opens and the propane solenoid valve closes.)
Choke Adjustment for Combination Carburetor: If the engine is equipped with a combination
carburetor, see that the gasoline shut-off valve is
closed. The electric choke (Figure 6-5) must be adjusted so the adjustable cover is turned 10 to 12
notches counterclockwise from the asterisk (*)
mark. When properly adjusted, the electric choke
will be completely open even at very low temperatures.
Gas Pressure: The fuel regulators in each line provide constant gas pressure at the gas mixer under
Gas fuel main adjustment should be made only
when a full electrical load is applied to the genset.
GASOLINE AND NATURAL GAS
NATURAL GAS AND LPG LIQUID
FIGURE 6-6. COMBINATION FUEL SYSTEMS
6-7
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Gaseous Fuel Adjustments: Gas mixers have
power and idle adjustment screws. Engines
equipped for natural gas and propane also have a
propane flow adjustment valve. If necessary, make
the following adjustments.
GAS MIXER
1. Start the engine and let the set warm up under
a partial load (at least 1/4 rated load). If the engine is equipped for natural gas and propane,
start with natural gas.
2. Disconnect all loads, shut down the set, connect a tachometer and disconnect the governor linkage at the carburetor. Start the engine
and close the throttle by hand so that the engine does not overspeed. While holding the
throttle closed, adjust the throttle idle position
screw (the one next to the throttle lever) to obtain an engine speed of 900 RPM. Then turn
the idle adjusting screw counterclockwise until
engine speed becomes unstable. Turn the
screw clockwise just enough to regain stability
and reconnect the governor linkage.
3. Next, connect full rated load and turn the power
adjusting screw clockwise until the engine begins to lose speed and then slowly back out the
screw (counterclockwise) until the engine carries the full load smoothly.
4. If the set is equipped for natural gas and propane, switch to propane by means of the control panel switch (if provided) or by closing the
manual shutoff valve in the natural gas supply
line.
5. Reconnect full rated load and turn the propane
flow adjustment valve clockwise until the engine begins to lose speed and then slowly turn
it back counterclockwise until the engine carries full load smoothly.
POWER
ADJUSTING
SCREW
IDLE
ADJUSTING
SCREW
THROTTLE
LEVER
PROPANE FLOW ADJUSTMENT VALVE
FIGURE 6-7. GASEOUS FUEL ADJUSTMENTS
6-8
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7. Wiring Diagrams
•
•
•
•
•
•
•
•
This section consists of the schematic and connection wiring diagrams referenced in the text.
The following diagrams are typical. Your genset may
differ. Wiring and component specifications are subject to change. Contact your Distributor if you do not
have the wiring diagrams applicable to your equipment.
The following drawings are included:
Page 7-4 – AC Wiring (with meters)
Page 7-5 – 7-light DC Wiring (Sheet 1 of 2)
Page 7-6 – 7-light DC Wiring (Sheet 2 of 2)
Page 7-7 – 12-light DC Wiring (Sheet 1 of 2)
Page 7-8 – 12-light DC Wiring (Sheet 2 of 2)
Pages 7-9 – Reconnection Diagram
Page 7-10 – Typical Connections to the ECM
Page 7-11 – Customer Connections at the Auxiliary Relay Board
• Page 7-12 – Engine Harness
• Page 7-2 – Voltage Regulator (VRAS-2) Installation
• Page 7-3 – AC Wiring (without meters)
• Page 7-13 – DC Harness
7-1
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VOLTAGE REGULATOR (VRAS-2) INSTALLATION
7-2
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THIS IS A REPRESENTATIVE (GENERIC)
SCHEMATIC/WIRING DIAGRAM. FOR
TROUBLESHOOTING, REFER TO THE
WIRING DIAGRAM PACKAGE THAT WAS
INCLUDED WITH YOUR GENSET.
No. 612-6489 sh 1 of 1
Rev. H Sys: CADAM
Modified 10/3/95
AC WIRING (WITHOUT METERS)
7-3
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THIS IS A REPRESENTATIVE (GENERIC)
SCHEMATIC/WIRING DIAGRAM. FOR
TROUBLESHOOTING, REFER TO THE
WIRING DIAGRAM PACKAGE THAT WAS
INCLUDED WITH YOUR GENSET.
No. 612-6490 sh 1 of 1
Rev. S Sys: CADAM
Modified 10/3/95
AC WIRING (WITH METERS)
7-4
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THIS IS A REPRESENTATIVE (GENERIC)
SCHEMATIC/WIRING DIAGRAM. FOR
TROUBLESHOOTING, REFER TO THE
WIRING DIAGRAM PACKAGE THAT WAS
INCLUDED WITH YOUR GENSET.
No. 612-6684 sh 1 of 2
Rev. A Sys: CADAM
Modified 9-26-95
7-LIGHT DC WIRING (SHEET 1 OF 2)
7-5
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THIS IS A REPRESENTATIVE (GENERIC)
SCHEMATIC/WIRING DIAGRAM. FOR
TROUBLESHOOTING, REFER TO THE
WIRING DIAGRAM PACKAGE THAT WAS
INCLUDED WITH YOUR GENSET.
No. 612-6684 sh 2 of 2
Rev. A Sys: CADAM
Modified 9-26-95
7-LIGHT WIRING (SHEET 2 OF 2)
7-6
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THIS IS A REPRESENTATIVE (GENERIC)
SCHEMATIC/WIRING DIAGRAM. FOR
TROUBLESHOOTING, REFER TO THE
WIRING DIAGRAM PACKAGE THAT WAS
INCLUDED WITH YOUR GENSET.
No. 612-6685 sh 1 of 2
Rev. A Sys: CADAM
Modified 9-27-95
12-LIGHT DC WIRING (SHEET 1 OF 2)
7-7
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THIS IS A REPRESENTATIVE (GENERIC)
SCHEMATIC/WIRING DIAGRAM. FOR
TROUBLESHOOTING, REFER TO THE
WIRING DIAGRAM PACKAGE THAT WAS
INCLUDED WITH YOUR GENSET.
No. 612-6685 sh 2 of 2
Rev. A Sys: CADAM
Modified 9-27-95
12-LIGHT DC WIRING (SHEET 2 OF 2)
7-8
Redistribution or publication of this document
by any means, is strictly prohibited.
THIS IS A REPRESENTATIVE (GENERIC)
SCHEMATIC/WIRING DIAGRAM. FOR
TROUBLESHOOTING, REFER TO THE
WIRING DIAGRAM PACKAGE THAT WAS
INCLUDED WITH YOUR GENSET.
No. 625-2068 sh 1of 1
Rev. B Sys: CADAM
Modified 10/2/95
RECONNECTION DIAGRAM
7-9
Redistribution or publication of this document
by any means, is strictly prohibited.
TB1-10 (SWITCHED B+ OUTPUT) OUTPUT TO RELAY K12, FUSED AT 20 AMPS, ENERGIZED WHEN THE
START SIGNAL IS APPLIED AND DE-ENERGIZED AT SHUTDOWN (NORMAL AND FAULT)
–
+
K12
TB1-9 (B+ INPUT) BATTERY POSITIVE (+) CONNECTION
TB1-8 (START SOLENOID) OUTPUT TO RELAY K11, FUSED AT 20 AMPS
K11
A15
TB1-7 (B+ OUTPUT) OUTPUT TO TIME DELAY START/STOP MODULE A15,
FUSED AT 15 AMPS, AVAILABLE WHEN THE STARTING BATTERIES ARE CONNECTED
TB1-6 (REMOTE START) CONNECTED TO TIME DELAY START/STOP MODULE A15. CONNECT REMOTE START
CONTACT OF THE AUTOMATIC TRANSFER SWITCH TO TERMINAL TB1-5 OF MODULE A15.
TB1-5 (GROUND)
TB1-4 (COMMON ALARM B+ OUTPUT) 4 AMP RATED DEVICE MAXIMUM
TB1-3 (RUN) CONNECTED TO TIME DELAY START/STOP MODULE A15
TB1-2 (DC DISCONNECT) CONNECTED TO TIME DELAY START/STOP MODULE A15
THIS IS A REPRESENTATIVE (GENERIC)
SCHEMATIC/WIRING DIAGRAM. FOR
TROUBLESHOOTING, REFER TO THE
WIRING DIAGRAM PACKAGE THAT WAS
INCLUDED WITH YOUR GENSET.
TB2-1 (FAULT 2) GROUND INPUT FROM SENDER
TB2-2 (FAULT 2) GROUND OUTPUT TO LIGHT/RELAY*
TB2-3 (FAULT 1) GROUND INPUT FROM SENDER
TB2-4 (FAULT 1) GROUND OUTPUT TO LIGHT/RELAY*
TB2-5 (REMOTE RESET) MOMENTARY CONTACT TO GROUND
TB2-6 (OVERCRANK FAULT) GROUND OUTPUT TO LIGHT/RELAY*
TB2-7 (OVERSPEED FAULT) GROUND OUTPUT TO LIGHT/RELAY*
TB2-8 (HIGH ENGINE TEMPERATURE FAULT) GROUND OUTPUT TO LIGHT/RELAY*
TB2-9 (LOW OIL PRESSURE FAULT) GROUND OUTPUT TO LIGHT/RELAY*
TB2-10 (PRE-HIGH ENGINE TEMPERATURE WARNING) GROUND OUTPUT TO LIGHT/RELAY*
TB2-11 (PRE-LOW OIL PRESSURE WARNING) GROUND OUTPUT TO LIGHT/RELAY*
CUSTOMER SUPPLIED WIRING
TB2-12 (SWITCH OFF WARNING) GROUND OUTPUT TO LIGHT/RELAY*
FACTORY WIRING
TB2-13 (LOW ENGINE TEMPERATURE WARNING) GROUND OUTPUT TO LIGHT/RELAY*
* 0.5 AMP RATED DEVICE MAXIMUM
TB2-14 (LOW FUEL WARNING) GROUND INPUT FROM SENDER
TB2-15 (LOW FUEL WARNING) GROUND OUTPUT TO LIGHT/RELAY*
TB2-16 (EMERGENCY SHUT DOWN) MOMENTARY CONTACT TO GROUND
FACTORY AND CUSTOMER CONNECTIONS AT THE ENGINE MONITOR BOARD TERMINALS
7–10
Redistribution or publication of this document
by any means, is strictly prohibited.
THE TERMINALS IN THE SHADED BOXES ARE FOR CUSTOMER CONNECTIONS
THIS IS A REPRESENTATIVE (GENERIC)
SCHEMATIC/WIRING DIAGRAM. FOR
TROUBLESHOOTING, REFER TO THE
WIRING DIAGRAM PACKAGE
WAS
NO.THAT
3004111
INCLUDED WITH YOUR GENSET.
REV. B
MODIFIED
625-2712
CUSTOMER CONNECTIONS AT THE AUXILIARY RELAY BOARD
7–11
Redistribution or publication of this document
by any means, is strictly prohibited.
THIS IS A REPRESENTATIVE (GENERIC)
SCHEMATIC/WIRING DIAGRAM. FOR
TROUBLESHOOTING, REFER TO THE
WIRING DIAGRAM PACKAGE THAT WAS
INCLUDED WITH YOUR GENSET.
LEAD TABULATION
FROM
STATION
TO
STATION
No. 336-3322 sh 1 of 1
Rev. A Sys: CADAM
Modified 9-26-95
ENGINE HARNESS
7-12
Redistribution or publication of this document
by any means, is strictly prohibited.
THIS IS A REPRESENTATIVE (GENERIC)
SCHEMATIC/WIRING DIAGRAM. FOR
TROUBLESHOOTING, REFER TO THE
WIRING DIAGRAM PACKAGE THAT WAS
INCLUDED WITH YOUR GENSET.
No. 338-3326 sh 1 of 1
Rev. A Sys: CADAM
Modified 9-27-95
DC HARNESS
7-13
Redistribution or publication of this document
by any means, is strictly prohibited.
Cummins Power Generation
1400 73rd Avenue N.E.
Minneapolis, MN 55432
1-800-888-6626
763-574-5000 International Use
Fax: 763-528-7229
Cummins is a registered trademark of Cummins Inc.
Redistribution or publication of this document
by any means, is strictly prohibited.