SERVICE MANUAL

Add to my manuals
36 Pages

advertisement

SERVICE MANUAL | Manualzz

Energy Saver

Commercial Electric Energy Saver

Water Heater

IMMERSION AND SURFACE MOUNTED

THERMOSTAT MODELS

SERVICE

MANUAL

Troubleshooting Guide and Instructions for Service

(To be performed ONLY by qualifi ed service providers)

For Models

50(A)*(SF, CF)-**

80(A)*(SF, CF)-**

120(A)*(SF, CF)-**

*Denotes kW Rating

**Denotes Wiring Code

Manual 238-47174-00B - Save this manual for future reference

2

Commercial Electric

Water Heaters

Table of Contents

Introduction/Tools

General Information

Sequence of Operation

Troubleshooting

Heating Element Testing

Line Voltage Testing

Fuse Testing

High Limit (ECO) Testing (Surface Mounted)

High Limit (ECO) Testing (Surface Mounted @ 600V)

High Limit (ECO) Testing (Contactor Models)

Thermostat Operation Testing (Surface Mounted)

Thermostat Operation Testing (Surface Mounted @ 600V)

Thermostat Operation Testing (Contactor Models)

Contactor Operation Testing

Thermostat Removal & Replacement (Surface Mounted)

Thermostat Removal & Replacement (Contactor Models)

ECO Removal & Replacement (Contactor Models)

ECO Removal & Replacement (Surface Mounted @ 600V)

Heating Element Removal & Replacement

Anode Inspection & Replacement

Generic Parts List

Glossary of Terms

23

24

26

27

19

20

21

22

15

16

17

18

2

3

10

13

28

29

30

31

32

33

Introduction

This service manual is designed to aid service and maintenance professionals in the function, proper diagnosis and repair of Bock Water Heaters Commercial Electric Water Heaters.

IX

X

XI

XII

V

VI

VII

VIII

I

II

III

IV

- - -

- - -

- - -

- - -

XIII

XIV

XV

XVI

- - -

- - -

The text and illustrations in this manual provide step-by-step instructions to facilitate proper operation and troubleshooting procedures. Contact Bock Water Heaters Technical Support immediately if diagnosis cannot be made using the methods described in this service manual.

Tools

- Multi-Meter

- 1-1/2” Deep Well Socket

- 1-1/16” Deep Well Socket

- 1/4” Nut Driver

- Philips Head Screw Driver

- Common Screw Driver

- Thermometer

- Drain Hose.

Other hand tools: pipe wrench, channel locks, pliers (common & needle nose), wire cutters, wire strippers, allen wrench set, fl ash light.

Commercial Electric

General Information

Bock Waters Heaters Commercial Electric water heaters can be manufacturered with a choice between two different types of thermostat control options as follows:

Surface Mounted Thermostats.

Immersion Thermostat (contactor models).

The model number is coded to identify the specifi c thermostat control system used for a particular unit. Below is a typical model number and coded defi nitions.

50 SF 6 208/240

Volts kW Rating

CF - Contactor w/Fuse (Immersion Thermostat)

SF - Surface Thermostat w/Fuse

Tank Capacity

Model Number

Electrical Characteristics

MFG FOR: BOCK WATER HEATERS, INC.

110 S. DICKINSON, MADISON WI 53703

Model No: 50SF-6, 208/240

Serial No: ZB2564812

Cap. 50(gal.)/189.3(liters)

Press: Test 300(psi), Working 150(psi)

Volts 240 Max 180° kW Each 4 Total kW 12 3 Elements

Wattage rating based upon 60 Hz

Typical Rating Plate

Located on Front of Water Heater

3

4

GENERAL INFORMATION

Contactor Models

General Controls Layout

Upper Control Box

Thermostat

Direct Immersion Bulb

Lower Control Box

Ground Lug

Terminal Block

Fuse Block (s)

Contactor (s)

High Limit (ECO)

Direct Immersion Bulb

High Limit (ECO) Control

Immersion Thermostat

Control

Heating Elements

Surface Mounted Thermostat Models

General Controls Layout

Upper Control Box

Ground Lug

Terminal Block

Fuse Block (s)

Lower Control Box

Surface Mounted

Thermostats with ECO

Heating Elements

GENERAL INFORMATION

600V Surface Thermostat (w/Contactors) Models

General Controls Layout

Ground Lug

Terminal Block

Upper Control Box

High Limit (ECO) Control

Contactor(s)

Surface Thermostats

Lower Control Box

Heating Elements

5

GENERAL INFORMATION

Surface Mounted Thermostats

Surface mounted thermostats are mounted into a bracket above each heating element. The bracket holds the thermostat against the side of the tank responding to tank surface temperatures to sense a call for heat, set point temperature and high limit (ECO) activation. As each element has a dedicated thermostat (for all models excluding

600V), it is possible to sequence the elements by varying the settings on the thermostats.

Manual ECO (High Limit)

Reset Button

Surface Mount

Combination Thermostat/

ECO (high limit)

89T Series

Temperature Control Dial

Immersion Style Thermostat Control for

Contactor Models

The thermostat will complete control circuit voltage upon a call for heat. Likewise, the control will interrupt control circuit voltage satisfy the adjustable temperature limit of control.

Direct

Immersion

Bulb

6

Immersion Style High Limit (ECO) Control for

Contactor Models

The high limit (ECO) control will interrupt control circuit voltage causing the heater to shut down when the high temperature limit of the control is reached

(196

° F ± 4° F). Once the cause for overheated water has been determined, the control must be manually reset to restore normal operation.

Manual Reset Button

Direct Immersion Bulb

GENERAL INFORMATION

Surface Mounted Thermostats (w/Contactors) for 600V Models

600V models use contactors to deliver line voltage to the heating elements. However, rather than the immersion type high limit and thermostat devices, surface mounted thermostats are used to operate the control circuit of the water heater.

Surface Mounted

Thermostat

59T Series

Surface Mounted

ECO (High Limit)

Temperature Control Dial Manual Reset Button

7

8

GENERAL INFORMATION

Contactor

Contactor operation is achieved by energizing an operating coil in response to a call for heat from the immersion thermostat. Upon a call for heat, one or more contactors will energize all heating elements simultaneously. The operating coils are voltage specifi c. When contactor replacement is required be sure to order the proper operating coil based on the voltage rating found on the rating plate located on the front of the water heater.

Terminal Connections to the

Fuse Block and/or Terminal Block

Terminal Connections to the Heating Elements

Terminal Connections of

Contactor Operating Coil

Direct Immersion “Screw-in” Type Heating Element

1- ½“ Hex

Screw-in Flange Terminal Block

Zinc-plated Copper or Incoloy Sheath

Terminal Block Screw Element Rating Ink Stamped on Side of Terminal Block

GENERAL INFORMATION

Commonly Used Formulas

(Single Phase)

Amps =

Watts

Volts

(Balanced 3 Phase)

Amps =

Watts

Volts x 1,732

Common Service Wire

Confi gurations

Watts = Amps x Volts

240V 1Ph

BLACK

Ungrounded

GREEN

Grounding

RED

Ungrounded

Volts

2

Ohms =

Watts

Neutral

120

120

208 3Ph

A B

120

208

208

208

C

RED BLACK RED

240

120

120

Neutral

120

120

240 3Ph

A B

120

240

240

240

C

RED BLACK RED

Neutral

480 3Ph/277 1Ph

A B C

277

277

277

480

480

480

RED BLACK RED

Commonly Used Formulas

36

45

54

18

24

27

30

208 Volt 240 Volt 277 Volt 380 Volt 415 Volt 480 Volt 600 Volt kW 1 Phase 3 Phase 1 Phase 3 Phase 1 Phase 3 Phase 3 Phase 1 Phase 3 Phase 3 Phase

6 28.8

16.6

25.0

14.4

21.6

9.1

8.3

12.5

7.2

5.8

9

12

13.5

15

43.2

57.6

64.9

72.1

25.0

33.3

37.5

41.6

37.2

50.0

56.2

62.5

21.6

28.9

32.5

36.1

32.4

43.3

48.7

54.1

13.6

18.2

20.5

22.7

12.5

16.7

18.8

20.9

18.7

25.0

28.1

31.2

10.8

14.4

16.2

18.0

8.7

11.5

13.0

14.4

86.5

115.4

129.8

144.2

173.0

216.3

259.6

50.0

66.7

75.0

83.3

100.0

125.0

150.0

75.0

100.0

112.5

125.0

150.0

187.5

225.0

43.4

57.8

65.0

72.2

86.7

108.3

130.0

64.0

86.6

97.4

108.3

129.9

162.4

194.9

27.3

36.4

41.0

45.6

54.7

68.4

82.0

25.0

33.4

37.5

41.7

50.1

62.6

75.1

37.5

50.0

56.2

62.5

75.0

93.7

112.5

21.6

28.9

32.5

36.1

43.3

54.1

65.0

17.3

23.1

26.0

28.9

34.6

43.3

52.0

9

10

SEQUENCE OF OPERATION

Bock’s commercial electric water heaters can use either immersion thermostats (contactor models) or surface mounted

thermostats. Sequence of operation for each confi guration is explained below. It would be impractical to show all wire diagrams applicable to both confi gurations. A “typical wiring diagram” is illustrated to aid in understanding the principles of the operating sequence.

Immersion Thermostats (Contactor Models): Confi gured to use a single immersion thermostat to control one or more contactors to energize or de-energize all elements simultaneously. In addition, a separate high limit (ECO) control with manual reset is wired in series with the thermostat. Both controls use a direct immersion bulb inserted into the tank to sense water temperature. Immersion thermostat and high limit control are mounted to provide temperature adjustment and manual reset access from the exterior of the unit.

Surface Mounted Thermostats: Surface mounted thermostats are mounted inside the lower control box, in a bracket above each heating element. The bracket holds the thermostat against the side of the tank, responding to tank surface temperatures to sense a call for heat, set-point temperature and high limit (ECO) activation. As each element is controlled by a dedicated thermostat, it is possible to sequence the elements by varying the settings on the thermostat. However, 600V models with surface mounted thermostats operate contactors in the same manner as an immersion thermostat model, only using surface thermostats to sense the call for heat.

Line Voltage

Sequence of operation for each system is explained below.

OR

Fuse Block

Terminal Block

Sequence of Operation:

Immersion Thermostat (Contactor Models).

The system has two distinct circuits:

1. Power Circuit (solid line).

2. Control Circuit (dotted line).

Contactor

Coil

Contactor

ECO

(High Limit)

1. Line voltage is applied across terminals of fuse block or a terminal block. Line voltage continues down and connects to terminals L1, L2 and L3 of one or more contactors.

A. Contactor is open (no call for heat), so there is no voltage across terminals T1, T2 and T3 of contactor.

T’stat

B. The contactor is controlled by the control circuit consisting of the immersion thermostat, ECO (high limit) and contactor coil.

2. When the thermostat calls for heat, contacts close inside the thermostat completing the circuit through the ECO and energizing the contactor coil.

3. The energized contactor coil causes the contactor to close energizing the elements from terminals T1, T2 and T3 of the contactor.

4. When the temperature setting of the thermostat is reached, the contacts in the thermostat open. This interrupts current fl ow through the control circuit de-energizing the contactor coil.

5. The de-energized contactor coil causes the contactor to open, interrupting current fl ow through the elements. The heater is now in stand-by, waiting for the next call for heat.

Heating Elements

Sequence of Operation:

Surface Mounted Thermostats.

1. Line voltage is applied across terminals of fuse block or a terminal block. Line voltage continues down and connects to surface mounted thermostats at terminals L1 and L3.

SEQUENCE OF OPERATION

1

Fuse Block

Line Voltage

Terminal Bloc

2. ECO (high limit) in thermostat is closed, so there is line voltage present at terminal L4 of thermostats and to one side of each element.

2

ECO Closed

Power to one side of element

3. Water in the tank is cold, so all thermostats are closed at terminal T2 (calling for heat). This completes the circuit and allows current to fl ow through heating elements.

Thermostat closed at terminal T2

3

4. As each thermostat is satisfi ed, it opens at terminal T2, interrupting current fl ow through the respective element. The system is now in stand-by mode waiting for the next call for heat.

Thermostat open at terminal T2

4

Surface Mounted

Thermostat

Heating Element

11

12

SEQUENCE OF OPERATION

Sequence of Operation:

600V Surface Mounted Thermostats (w/Contactors).

The system has two distinct circuits.

1. Power Circuit - Line Voltage (600V)

2. Control Circuit - 120V

1. Line voltage is applied across terminals of fuse block or a terminal block. Line voltage continues down and connects to terminals L1, L2 and L3 of one or more contactors.

A) Contactor is open (no call for heat), so there is no voltage across terminals T1, T2, and T3 of contactor.

B) The contactor is controlled by the control circuit consisting of the surface mounted thermostat, ECO (high limit) and contactor coil.

2. When the thermostat calls for heat, contacts close inside the thermostat completing the circuit through the ECO and energizing the contactor coil.

3. The energized contactor coil causes the contactor to close, energizing the elements from terminals T1, T2 and T3 of the contactor.

4. When the temperature setting of the thermostat is reached, the contacts in the thermostat open. This interrupts current fl ow through the control circuit de-energizing the contactor coil.

5. The de-energized contactor coil causes the contactor to open, interrupting current fl ow through the elements. The heater is now in stand-by waiting for the next call for heat.

6. Notice in the wiring diagram at right that each row of elements is equipped with a surface mounted thermostat on the highest element in the row. These thermostats are individually wired in series to the contactor whose line voltage corresponds to the same row of elements. Each thermostat and contactor combination are wired to the

ECO in parallel. This allows for each row of elements to be powered “ON” independent of the other element rows.

However, the ECO is wired in series so that voltage can be interrupted to the entire control circuit if the ECO senses that the tank water has become overheated.

Transformer

60VA

6 Element Configuration Shown

(9 Elements Possible)

Fuse Block

High Limit

Line Voltage

Contactor

59T

59T

Heating Elements

TROUBLESHOOTING

The most common cause of improper electric water heater operation can be linked to heating element failure.

always a good idea to check the heating elements fi rst following the procedure on Page 15.

Common heating element failures are:

1. Dry Firing. Elements may be partially submerged in water or most likely, completely exposed with no water in the tank at all. In open air, an energized element (dry-fi red) will become completely inoperable within seconds. In some cases sediment or lime build up around an element can eventually cause an air pocket, resulting in a dry-fi red element. When element replacement is required, be sure tank is full of water prior to energizing the water heater.

2. Grounded Element. In most cases, an element with a short circuit to ground will cause the circuit breaker in the service panel to open or shut off . In some cases there may not be enough current draw for the circuit breaker to open. This will allow the heating element to be in continuous operation resulting in overheated water, limited only by the ECO located in the thermostat circuit. Repeated actuation of the ECO usually is the result of a grounded heating element.

3. Sediment Buildup. Slow hot water recovery can usually be traced back to sediment or lime build-up around heating element. Sediment build-up can also, over time, cause a dry-fi red element.

If a heating element is found to be inoperative, it must be replaced. Follow service procedure MCE-XV on Page 30.

The illustration below shows a common “screw-in” type heating element identifying certain features commonly referred to throughout this manual.

Typical Direct Immersion “Screw-In” Type Heating Element

1- ½“ Hex

Screw-in Flange

Terminal Block

Zinc-plated Copper or Incoloy Sheath

Terminal Block Screw Element Rating Ink Stamped on Side of Terminal Block

13

14

TROUBLESHOOTING

Quick Step Plan to Hot Water

1. STOP, DANGER! Turn power “OFF” to water heater.

2. Check all wire connections to insure that they are snug and corrosion free.

3. Reset high limit (ECO) (Page 18-20).

4. Check for inoperative heating element (Page 15).

5. Check line voltage (Page 16), and internal fuses (Page 17).

6. Refer to table below if items 1 through 5 above do not correct problem.

WARNING

High voltage exposure. Use caution when making voltage checks to avoid hazard to life or property.

SYMPTOM PROBABLE CAUSE

No Hot Water

Not Enough

Hot Water or

Continues

Operation

Slow Hot Water

Recovery

Overheated

Water

Noisy (singing or hissing) Elements

Noisy Contactor

1. No power to heater.

2. Blown water heater fuses.

3. Loose wire connections.

4. Inoperative heating elements.

5. Inoperative thermostat(s)

6. Open ECO.

7. Inoperative contactor(s).

1. Inoperative heating element.

2. Sediment or lime buildup on element(s).

3. Thermostat(s) set too low.

4. Inoperative thermostat(s).

5. Inoperative contactor(s).

6. Loose wire connection.

7. High demand period.

8. Undersized heater.

9. Very cold inlet water to heater.

10. Plumbing connections reversed.

1. Sediment or lime buildup on element(s).

2. Loose wire connections.

3. Inoperative thermostat(s).

4. Inoperative contactor(s).

5. Derated heating element installed.

1. Surface thermostat(s) not fl ush with tank.

2. Grounded heating element(s).

3. Thermostat set too high.

4. Inoperative thermostat(s).

5. Inoperative ECO.

1. Lime formation on element(s).

2. High or low line voltage.

1. Low line voltage.

2. Debris between contactor plates.

3. Incorrect or defective operating coil.

4. Loose wire connections.

CORRECTIVE ACTION

1. Check circuit breakers at service panel.

2. Check water heater fuses.

3. Check all wire connections.

4. Check heating element(s).

5. Check thermostat(s) operation.

6. Reset (check) ECO.

7. Check contactor operation.

1. Check heating element(s).

2. Clean or replace heating element(s).

3. Increase thermostat setting.

4. Check thermostat(s).

5. Check contactor operation.

6. Check all wire connection.

7. Reduce demand.

8. Replace with larger heater.

9. Temper water to heater.

10. Correct plumbing connections.

1. Clean or replace heating elements.

2. Check all wire connections.

3. Check thermostat(s).

4. Check contactor operation.

5. Verify element voltage and wattage rating.

1. Check surface thermostat(s) mounting.

2. Check heating element(s).

3. Adjust thermostat(s) to desired setting.

4. Check thermostat(s).

5. Check ECO.

1. Clean or replace heating element(s).

2. Verify line voltage to heater.

1. Verify line voltage to heater.

2. Replace contactor.

3. Replace contactor.

4. Check wire connections.

SERVICE

PROCEDURE

2. III, Page 17

4. I, Page 15

5. VII-IX, Page 21-23

6. IV, VI, Page 18-20

7. X, Page 24-25

1. I, Page 15

2. XV, Page 30

4.VII-IX, Page 21-23

5. X, Page 24-25

1. XV, Page 30

3. VII-IX, Page 21-23

4. X, Page 24-25

5. See Page 8

1. XI, Page 26

2. I Page 15

4. VII-IX, Page 21-23

5. IV-VI, Page 18-20

1. XV, Page 30

2. II, Page 16

1. II, Page 16

Test for Open or Burned Out Element.

1. STOP, DANGER! Turn power “OFF” to water heater.

2. Remove access cover from lower control box. Remove insulation from inside of control box.

3. Disconnect wires from heating element.

4. Set multi-meter to “ohms” setting.

5. Touch probes of multi-meter to screw terminals of heating element (see illustration 1).

6. Reading should be 12.8 ohms (± 6%) for a 240 volt, 4500 watt element, see table below for other elements.

Ohms = Volts 2

Watts

A reading outside the range using the formula above (± 6%) indicates a bad element and the element must be replaced.

Element

Ohms of Electrical Resistance for Commonly Used Elements

Voltage Rating of Element

3000 14.4 19.2 76.8

4000 10.8 14.4 57.6

4500 9.6 12.8 51.2

5000 8.7 11.5 46.1

6000 7.2 9.6 38.4

Test for Grounded Heating Element

(Damaged Heating Element with Short Circuit to Ground).

1. STOP, DANGER! Turn power “OFF” to water heater.

2. Remove access cover from lower control box. Remove insulation from inside of control box.

3. Disconnect wires from heating element.

4. Set multi-meter to “ohms” setting.

5. Touch one probe of multi-meter to either screw terminal of heating element and the other on the element fl ange

(see illustration 2). There should be no reading on the ohm meter. Any reading indicates a grounded element and the element must be replaced. Repeat this step for the other screw terminal.

SERVICE PROCEDURE I

Heating Element Testing

WARNING

High voltage exposure. To avoid hazard to life or property, be sure power is turned

OFF to water heater while performing this procedure.

NOTE

Disconnect

Element

Wires

Element Screw Terminals

Illustration 1

NOTE

Disconnect

Element

Wires

Element Flange

Element

Screw Terminal

Illustration 2

15

16

SERVICE PROCEDURE II

Line Voltage Testing

Line Voltage Testing.

Line voltage (single phase or three phase) will connect to a terminal block or directly to a fuse block located inside the control panel.

Determine heaters voltage and phase by referring to the rating plate located on the front of the water heater. Apply the appropriate phase procedure below to determine if proper line voltage is present.

Single Phase Line Voltage Testing.

1

. STOP, DANGER! Turn power “OFF” to water heater.

2. Open upper control panel door.

3. Determine connection point for line voltage from service panel, terminal block or fuse block.

4. Set multi-meter to volts AC. Be sure to scale meter for appropriate voltage.

5. Use caution and turn power “ON” to water heater.

6. Use caution and check voltage across top terminals where service voltage connects to water heater (see illustration 3).

A) Rated voltage IS present, power to the water heater is okay.

B) Rated voltage NOT present, check service panel.

Three Phase Line Voltage Testing.

1. STOP, DANGER! Turn power “OFF” to water heater.

2. Open upper control panel door.

3. Determine connection point for line voltage from service panel, terminal block or fuse block.

4. Set multi-meter to volts AC. Be sure to scale meter for appropriate voltage.

5. Use caution and turn power “ON” to water heater.

6. Use caution and check voltage across top terminals where service voltage connects to water heater (see illustration 4).

A) Rated voltage IS present, power to the water heater is okay.

B) Rated voltage NOT present, check service panel.

WARNING

High voltage exposure. To avoid hazard to life or property, use extreme caution when making voltage checks.

Line voltage from service panel connected to Terminal block of heater

OR

Line voltage from service panel connected to Fuse block of heater

Check voltage across top terminals.

Illustration 3

Line voltage from service panel connected to Terminal block of heater

OR

Check voltage across top terminals.

Illustration 4

Line voltage from service panel connected to Fuse block of heater

Fuse Testing.

1. STOP, DANGER! Turn power “OFF” to water heater.

2. Open upper control box to allow access to fuse block.

3. Locate fuse block and remove fuses.

4. Set multi-meter to the ohms setting.

5. Check continuity across fuse (see illustration 5).

A) Continuity IS present, fuse is okay.

B) Continuity NOT present, replace fuse.

SERVICE PROCEDURE III

Fuse Testing

WARNING

High voltage exposure. To avoid hazard to life or property, be sure power is turned

OFF to water heater while performing this procedure.

Illustration 5

17

18

SERVICE PROCEDURE IV

High Limit (ECO) Testing

High Limit Control (ECO) Testing for

Surface Thermostat Models (NOT including 600V)

WARNING

High voltage exposure. To avoid hazard to life or property, use extreme caution when making voltage checks.

1. This procedure assumes line voltage and fuses are in working order.

2. This procedure illustrates testing of just one surface thermostat. Repeat this procedure for all surface thermostats on the water heater.

ECO reset button

3. Turn power “OFF” to water heater.

4. Remove lower control box cover and remove insulation from inside of control box.

5. Remove plastic cover from thermostat(s).

6. Turn power “ON” to water heater.

7. Use caution and check voltage across terminals L1 and L4 for all thermostats (see illustration 6).

A) Rated voltage IS present, ECO is okay.

B) Rated voltage NOT present, proceed to step 8.

ELEMENT

Illustration 6

8. Turn power “OFF” to water heater and fi rmly press ECO reset button on thermostat(s).

Turn power “ON” to water heater and recheck voltage across terminals L1 and L4 of thermostat(s).

A) Rated voltage IS present, the ECO has previously opened indicating the water in the tank, at some point, did overheat.

Check the following:

1. Thermostat must be in full contact with tank.

2. Be sure heating element(s) is not shorted to ground (see Page 15).

3. Proper thermostat operation (see Page 21).

B) Rated voltage NOT present, water in tank may be overheated.

1. If water is overheated, turn “OFF” power to water heater and fl ow water through tank to cool below set point of upper thermostat. Reset ECO and recheck voltage.

2. If water is cool, replace thermostat(s).

SERVICE PROCEDURE V

High Limit (ECO) Testing

High Limit Control (ECO) Testing for

600V Surface Thermostat Models.

WARNING

High voltage exposure. To avoid hazard to life or property, use extreme caution when making voltage checks.

1. This procedure assumes line voltage, transformer, fuses and thermostat are in working order.

2. Turn power “OFF” to water heater.

3. Remove lower control box cover and remove insulation from inside of control box.

ECO reset button

4. Use caution and check continuity across terminals 1 and 2 (see illustration 7).

A) Continuity IS present, ECO is okay.

B) Continuity NOT present, proceed to step 5.

5. Turn power “OFF” to water heater and fi rmly press ECO reset button on thermostat(s). Turn power “ON” to water heater and recheck continuity across terminals 1 and 2 of thermostat(s).

A) Continuity IS present, the ECO has previously opened indicating the water in the tank, at some point, did overheat. Check the following:

Illustration 7

1. Thermostat must be in full contact with tank.

2. Be sure heating element(s) is not shorted to ground (see Page 15).

3. Proper thermostat operation (see Page 22).

B) Continuity NOT present, water in tank may be overheated.

1. If water is overheated, turn “OFF” power to water heater and fl ow water through tank to cool below set point of upper thermostat. Reset ECO and recheck continuity.

2. If water is cool, replace ECO.

19

20

SERVICE PROCEDURE VI

High Limit (ECO) Testing

High Limit Control (ECO) Testing for

Contactor Models

Switch Contacts:

Normally closed.

Open on rise @ 196 °F ± 4°F.

Manual Reset.

1. Determine of high limit (ECO) has actuated. This can be done by simply depressing the reset buttons. If you hear and/or feel a small click, the switch has actuated.

2. Use caution and turn power on to water heater and observe heating cycle following the high limit heating cycle fl ow chart.

High Limit Control Continuity Testing for

Contactor Models

1. STOP, DANGER! Turn power “OFF” to water heater.

2. Water temperature must be below 196

°F ± 4°F.

3. Remove high limit switch from control panel. It is not necessary to remove immersion bulb from tank at this time. See general controls layout on Page 4 for location.

4. Disconnect wire leads to high limit control during this test.

5. Depress reset buttons to insure switch contacts are closed.

6. Set multi-meter to ohms setting. Check continuity through circuit A and B as showing in the illustrations below.

A) Continuity IS present, switch is okay.

B) Continuity NOT present, replace switch.

WARNING

High voltage exposure. To avoid hazard to life or property, be sure power is turned

OFF to water heater while performing this procedure.

Observe heating cycle.

Does switch open?

N

Y

Is water temperature over 196 °F?

N

Y

Replace switch.

Is water temperature over 196 °F?

Y

Switch OK.

High Limit Heating Cycle Flow Chart

NOTE

Disconnect

Wire Leads to Control

Circuit “A” Continuity Testing Circuit “B” Continuity Testing

SERVICE PROCEDURE VII

Thermostat Testing

Surface Mounted Thermostat.

Operation Testing (NOT including 600V).

Water in Tank is Cold with Power ON.

1. This procedure assumes line voltage, ECO and elements are in working order.

2. Turn power “OFF” to water heater.

High voltage exposure. To avoid hazard to life or property, use extreme caution when making voltage checks.

3. Remove access cover from lower control box.

Remove insulation from inside of control box.

Remove plastic cover from thermostat.

4. Turn power “ON” to water heater.

5. Set multi-meter to Volts AC.

6. Use caution and check voltage across terminals L1 and L3 for all thermostats (see illustration 8).

ELEMENT

Illustration 8

A) Rated voltage NOT present, check fuses and/or line voltage.

B) Rated voltage IS present, proceed to step 7.

7. Check across terminals L4 and T2 of thermostat (see illustration 9).

A) Rated voltage NOT present, recheck ECO. If ECO is okay, replace thermostat.

B) Rated voltage IS present, thermostat is calling for heat, go to step 8.

8. Check across element terminals (see illustration 10)

A) Rated voltage NOT present, check wire connections from thermostat to element.

B) Rated voltage IS present, repeat element testing (see Page 15).

WARNING

ELEMENT

Illustration 9

ELEMENT

Illustration 10

Water in Tank is Above Thermostat Settings.

1. This procedure assumes line voltage, ECO and elements are in working order.

2. Turn power “ON” to water heater.

3. Set multi-meter to Volts AC.

4. See illustration 9, check across terminals L4 and T2 of thermostat.

A) Rated voltage IS present, replace thermostat.

B) Rated voltage NOT present, thermostat is okay.

C) Lower than rated voltage IS present, recheck for grounded element (see Page 15).

21

22

SERVICE PROCEDURE VIII

Thermostat Testing

600V Surface Mounted Thermostat Models

Operation Testing.

Water in Tank is Cold with Power ON.

1. This procedure assumes line voltage, ECO, transformer,

thermostat, and elements are in working order.

2. Turn power “OFF” to water heater.

WARNING

High voltage exposure. To avoid hazard to life or property, use extreme caution when making voltage checks.

3. Remove access cover from lower control box.

Remove insulation from inside of control box.

4. Using a phillips head screwdriver, disconnect the wire lead at terminal 2 of the thermostat. Only check one thermostat at a time to insure wires are correctly reinstalled upon completion. Mark wires if necessary for reinstallation.

5. Set multi-meter to check continuity.

6. Use caution and check continuity across terminals 1 and 2 for all thermostats (see illustration 11).

A) Continuity NOT present, replace thermostat.

B) Continuity IS present, thermostat is okay.

Illustration 11

Water in Tank is Above Thermostat Settings.

1. This procedure assumes line voltage, ECO, thermostat, transformer, and elements are in working order.

2. Turn power “OFF” to water heater.

3. Remove access cover from lower control box. Remove insulation from inside of control box.

4. Using a phillips head screwdriver, disconnect the wire lead at terminal 2 of the thermostat. Only check one thermostat at a time to insure wires are correctly reinstalled upon completion. Mark wires if necessary for reinstallation.

5. Set multi-meter to check continuity.

6. Use caution and check continuity across terminals 1 and 2 for all thermostats (see illustration 11).

A) Continuity NOT present, replace thermostat.

B) Continuity IS present, thermostat is okay.

SERVICE PROCEDURE IX

Thermostat Testing

Immersion Thermostat Operation Testing.

Thermostat Specifi cation.

Calibration: 184 °F/176°F

Max Diff erential: 6 °F

Operating Range: 80 °F to 180°F

WARNING

High voltage exposure. To avoid hazard to life or property, use extreme caution when making voltage checks.

Providing the water temperature in tank is within the operating range of the thermostat, checking thermostat operation can be as simple as rotating the thermostat dial and listening to the contactor(s) to see if they respond to a call for heat.

Use caution and turn power “ON” and rotate the thermostat dial to call for heat.

With water temperature below the thermostat setting, the contactor(s) close.

With the contacts closed, use caution and check for rated voltage across lower terminals of contactor(s) (see illustration 12). If rated voltage is present, the thermostat is calling for heat.

Rotate thermostat dial to the minimum setting. With water temperature above the thermostat setting the contactor(s) will open. With the contacts open, voltage should not be present at lower terminals of contactor(s).

Check voltage across lower terminals of contactor(s)

Illustration 12

Thermostat Control Continuity Testing.

1. This procedure assumes line voltage, ECO and contactor(s) are in working order.

2. Turn power “OFF” to water heater.

3. Remove access cover from lower control box. Remove insulation from inside of control box.

4. Locate thermostat control (see general controls layout on Page 4) and remove wire leads to

control screw terminals.

5. Water temperature in tank must be within operating range of thermostat for this test. If above or below, it will be necessary to drain tank and remove thermostat immersion bulb from tank to warm or cool the bulb to be within operating range of thermostat.

Thermostat Immersion Bulb

6. Set multi-meter to the “Ohms” setting.

7. Rotate thermostat dial to highest setting.

8. Check across screw terminals of control

(see illustration 13).

A) Continuity NOT present, replace thermostat.

B) Continuity IS present, proceed to step 9.

9. Rotate thermostat dial to lowest setting.

10. Check across screw terminals of control

(see illustration 13).

A) Continuity NOT present, thermostat is okay.

B) Continuity IS present, replace thermostat.

NOTE: Disconnect

Wire Leads to Control

Screw Terminals

L1 L2 L3

T1 T2 T3

Thermostat

Dial

Illustration 13

23

24

SERVICE PROCEDURE X

Contactor Testing

Contactor Operation Testing.

WARNING

High voltage exposure. To avoid hazard to life or property, use extreme caution when making voltage checks.

Noisy Contactor.

Noisy or chattering contactor operation in most cases is due to voltage variations being supplied to the water heater.

Extended periods of voltage variations will cause damage to the operating coil of the contactor causing noisy operation.

Determine that service voltage to the unit meets the electrical requirements per the rating plate located on the front of the water heater.

In addition, debris between the contact plates will cause noisy operation.

Contactor Operating Coils.

Contactor operation is achieved by energizing an operating coil in response to a call for heat from the thermostat. There are three diff erent operating coils used depending on voltage rating of the water heater as follows:

Description

Color Code

208/240 Volt Coil Green

277 Volt Coil

480 Volt Coil

Blue

Black

All the coils have a color code for visual confi rmation. In addition, the 277 and 480 volt coils are labeled with voltage rating for proper identifi cation. All contactors supplied for replacement are equipped with the 208/240 volt operating coil. By removing the rear mounting plate of the contactor, the operating coils can be changed based on desired service voltage. When contactor replacement is required be sure to order the proper operating coil base on the voltage rating found on the rating plate located on the front of the water heater.

Rear Mounting Plate

Operating Coil

Color Code Location

Identification Label Location

SERVICE PROCEDURE X

Contactor Testing

Contactor Operation Testing (continued).

This procedure assumes control circuit is operating correctly.

Providing the water temperature in tank is within the operating range of the thermostat, checking contactor operating can be as simple as rotating the thermostat dial and listening to the contactor(s) to see if they respond to a call for heat.

1. Turn power “ON” and rotate thermostat dial to the maximum setting. With water temperature in tank below the thermostat setting the contactor(s) will close. With the contacts closed, check for line voltage across operating coil terminals (see illustration 14).

WARNING

High voltage exposure. To avoid hazard to life or property, use extreme caution when making voltage checks.

A) Line voltage IS present, go to step 2.

B) Line voltage NOT present, verify control circuit operation.

2. Check for rated voltage across lower terminals of contactor(s)

(see illustration 15).

A) Rated voltage IS present, go to step 3.

B) Rated voltage NOT present, replace contactor.

3. Rotate thermostat dial to the minimum setting. With water temperature in tank above thermostat setting, the contactor(s) will open. With the contacts open, voltage should not be present at lower terminals of contactor(s).

4. Check for line voltage across operating coil terminals

(see illustration 14).

A) Line voltage IS present, verify control circuit operation.

B) Line voltage NOT present, go to step 5.

5. Check for rated voltage across lower terminals of contactor(s)

(see illustration 15).

A) Rated voltage IS present, replace contactor.

B) Rated voltage NOT present, contactor is okay.

Illustration 14

Check voltage across lower terminals of contactor(s)

Illustration 15

L1 L2 L3

T1 T2 T3

25

26

SERVICE PROCEDURE XI

Thermostat Removal and Replacement

Surface Mounted Thermostat Removal and Replacement

1. STOP, DANGER! Turn power “OFF” to water heater.

2. Remove access cover from lower control. Remove insulation from inside of control box. Remove plastic cover from thermostat.

WARNING

High voltage exposure. To avoid hazard to life or property, be sure power is turned

OFF to water heater while performing this procedure.

3. Disconnect wires from thermostat terminals. It may be necessary to label wires for proper reconnection to new thermostat.

4. Note thermostat temperature setting for proper setting of new thermostat.

5. Slide thermostat upwards and out of mounting bracket.

6. Use a stiff brush to remove any debris or loose scale from tank surface where new thermostat will be installed.

7. Slide new thermostat down into thermostat bracket until it snaps into place. IMPORTANT - thermostat must set completely fl at or fl ush to tank surface. An improperly installed thermostat will cause improper water heater operation.

8. Refer to the wire diagram located on the inside of the upper control box cover and reconnect wires to the thermostat. Be sure wire connections are snug and corrosion free. Do not over tighten as that may damage thermostat.

9. Set thermostat to the original thermostat setting found on the old thermostat.

10. Restore power to water heater and verify proper heater operation.

Tank Surface

Proper Thermostat mounting flush with tank surface

Thermostat

Improper Thermostat mounting.

Thermostat not flush with tank surface

Thermostat mounting bracket

Front View

Thermostat Mounting

Side View

Proper Thermostat

Mounting

Side View

Improper Thermostat

Mounting

SERVICE PROCEDURE XII

Thermostat Removal and Replacement

Immersion Thermostat Removal and Replacement

1. STOP, DANGER! Turn power “OFF” to water heater.

2.Turn off cold water supply to heater. Connect hose to drain spigot of water heater and route to an open drain. Open a nearby hot water faucet to vent heater for draining. Open drain spigot of water heater and allow water heater to drain to a point below the immersion bulb location (see illustration 16).

3. Close drain spigot and remove hose.

4. Remove lower control box cover and insulation.

5. Locate thermostat inside lower control box mounted

to the right side of the box below the ECO control

(see illustration 16).

6. Follow copper capillary tube from thermostat to the immersion bulb location and remove immersion bulb from tank using 11/16” wrench.

7. Remove (pull) thermostat control dial from stem of thermostat.

8. Remove the two thermostat mounting screws located under thermostat dial (see illustration 16).

9. Once thermostat is removed, disconnect wire leads to the thermostat. NOTE: It may be necessary to identify wires for proper reconnection to new thermostat.

10. Refer to wiring diagram located on the inside of the upper control box cover and properly reconnect wire leads to new thermostat and remount control inside control box using screws from step 8.

11. Replace control dial to stem of thermostat.

12. Loosen ferrule nut of immersion bulb (see illustration 17).

Immersion

Bulb

Ferrule

Nut

Immersion

Thermostat Bulb

Location

Copper Capillary

Tube

Immersion

Thermostat

Control

WARNING

High voltage exposure. To avoid hazard to life or property, be sure power is turned

OFF to water heater while performing this procedure.

Illustration 16

ECO

Control

Thermostat Control

Mounting Screws

Located Under

Thermostat Dial

Copper

Capillary

Tube

Tank

Nut

Illustration 17

13. Position tank nut at end of immersion bulb as shown in illustration 17. Insert immersion bulb into tank and tighten tank nut.

14. Gently pull copper capillary tube to insure the immersion bulb is in a horizontal position as shown in illustration 17 and tighten ferrule nut.

15. Resume water supply, full tank and check for leaks.

16. Be sure tank is full of water and resume power supply to water heater. Verify proper thermostat operation.

27

28

SERVICE PROCEDURE XIII

Contactor Model High Limit (ECO) Control

Removal and Replacement

Contactor Model High Limit (ECO) Control

Removal and Replacement.

1. STOP, DANGER! Turn power “OFF” to water heater.

WARNING

High voltage exposure. To avoid hazard to life or property, be sure power is turned

OFF to water heater while performing this procedure.

2.Turn off cold water supply to heater. Connect hose to drain spigot of water heater and route to an open drain. Open a nearby hot water faucet to vent heater for draining. Open drain spigot of water heater and allow water heater to drain to a point below the immersion bulb location (see illustration 18).

3. Close drain spigot and remove hose.

4. Remove lower control box cover and insulation.

5. Locate ECO Control inside lower control box mounted

to the right side of the box above the thermostat control

(see illustration 18).

6. Follow copper capillary tube from ECO Control to the immersion bulb location and remove immersion bulb from tank using

11/16” wrench.

ECO

Immersion Bulb

Location

7. Remove the two ECO control mounting screws located outside the lower control box.

Copper Capillary

Tube

8. Once ECO control is removed, disconnect wire leads to the control. NOTE: It may be necessary to identify wires for proper reconnection to new control.

9. Refer to wiring diagram located on the inside of the upper control box cover and properly reconnect wire leads to new ECO control and remount control inside control box using screws from step 7.

10. Loosen ferrule nut of immersion bulb. (see illustration 19).

ECO

Control

Thermostat

Control

Immersion

Bulb

Ferrule

Nut

Illustration 18

Copper

Capillary

Tube

Tank

Nut

Illustration 19

11. Position tank nut at end of immersion bulb as shown in illustration 19. Insert immersion bulb into tank and tighten tank nut.

12. Gently pull copper capillary tube to insure the immersion bulb is in a horizontal position as shown in illustration 19 and tighten ferrule nut.

13. Resume water supply, full tank and check for leaks.

14. Be sure tank is full of water and resume power supply to water heater. Verify proper ECO operation.

SERVICE PROCEDURE XIV

600V Model High Limit (ECO) Control

Removal and Replacement

600V Surface Thermostat Model High Limit (ECO) Control

Removal and Replacement.

1. STOP, DANGER! Turn power “OFF” to water heater.

2. Remove lower control box cover and insulation.

WARNING

High voltage exposure. To avoid hazard to life or property, be sure power is turned

OFF to water heater while performing this procedure.

3. Locate high limit switch (ECO) mounted to the tank above the element spuds (see illustration 20).

4. Disconnect wire leads to the ECO. NOTE: It may be necessary to identify wires for proper reconnection to the new control.

5. Remove the two ECO mounting nuts holding the sensor to the tank.

Take care not to damage the mounting studs.

6. Fasten the replacement ECO to the tank using the nuts from step

5. Take care not to damage the mounting studs. Refer to wiring diagram located on the inside of the upper control box cover and properly reconnect wire leads to new ECO.

7. Verify proper ECO operation.

High Limit Switch

Mounting Stud

Illustration 20

29

30

SERVICE PROCEDURE XV

Heating Element Removal and Replacement

Heating Element Removal and Replacement.

1. STOP, DANGER! Turn power “OFF” to water heater.

2. Turn off cold water supply to heater. Connect hose to drain spigot of water heater and route to an open drain. Open a nearby hot water faucet to vent heater for draining. Open drain spigot of water heater and allow heater to drain to a point below the element(s).

WARNING

High voltage exposure. To avoid hazard to life or property, be sure power is turned

OFF to water heater while performing this procedure.

3. Close drain spigot and remove hose.

4. Remove access cover and insulation from lower control box. Remove plastic cover from thermostat.

5. Disconnect wires from element terminals.

WARNING

Heater components and stored water may be

HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury.

6. Remove element from tank using 1-½” deep well socket or appropriate wrench. Unscrew element counter-clockwise to remove from tank.

7. Be sure to remove old element gasket from the tank. It is recommended to replace the gasket with a new one.

8. Check new element terminal block for proper electrical rating. NOTE: Some elements have dual ratings, be sure to check all surfaces of the element terminal block (see illustration 21).

9. Apply new element gasket to the new element. Be sure gasket is seated fl at against element fl ange without rolls or gaps

(see illustration 21).

10. Clean any debris from element fi tting on tank.

11. Thread new element clockwise into tank. Tighten element using 1-½” deep well socket or appropriate wrench. Do not over tighten, over tightening may damage element gasket.

12. Reconnect wires to element. Be sure connections are snug and corrosion free. Do not over right as that may damage terminal block.

13. Resume water supply to heater. Be sure tank is full of water and check for leaks.

14. Reinstall plastic thermostat protector(s).

15. Reinstall insulation and control box cover.

16. To resume operation BE SURE TANK IS FULL OF WATER and restore power to water heater. Verify proper heater operation.

Date Code

Element Rating.

Example: (4500 Watt, 240 Volt)

Element Flange

Element Gasket Seated Flat Against

Element Flange Without Rolls or Gaps

Terminal

Block

Manufacturer Identification

Illustration 21

SERVICE PROCEDURE XVI

Anode Rod Inspection and Replacement

Anode Rod Inspection and Replacement.

1. STOP, DANGER! Turn power “OFF” to water heater.

2. Turn off cold water supply to heater. Connect hose to drain spigot of water heater and route to an open drain. Open a nearby hot water faucet to vent heater for draining. Open drain spigot of water heater and allow heater to drain to a point below the anode rod locations at the top of the tank.

3. Close drain spigot and remove hose.

4. Remove the plastic anode rod access plugs at the anode rod locations.

WARNING

High voltage exposure. To avoid hazard to life or property, be sure power is turned

OFF to water heater while performing this procedure.

WARNING

Heater components and stored water may be

HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury.

5. Remove anode rods from the water heater using a 1-1/16” socket wrench.

6. Visually inspect anode rods. Anode rods should show signs of depletion, this is normal. If depletion is 1/2 of the original anode rod diameter (original diameter is approximately

¾”), replacement is recommended. If any of the steel core of the anode rod is exposed, replacement is recommended.

7. Upon completion of inspection and/or subsequent replacement of the anode rod, reinstall the anode into the water heater, resume water supply, refi ll water heater with water and check for leaks.

8. To resume operation, BE SURE TANK IS FULL OF WATER and turn power “ON” to water heater.

Anode Rod Locations

31

32

GENERIC PARTS LIST

FUSES TERMINAL BLOCKS FUSE BLOCKS CONTACTORS

31

34

33

32

39

36

37

35 35 38

1

30

40 41

CONTACTOR COILS

42

2

43 44 45

GROUND LUGS

46 47

48

TRANSFORMER

(600V ONLY)

50

28

49

29

27

5A

25

26

23

22

21

20

18

19 17

16

15

14

24

5

9

3

3A

4

4A

6

7

10

10A

11/11A

12/12A

13

8

GENERIC PARTS LIST

Item Description

21

22

23

16

17

18

19

20

6

7

5

5A

8

1

2

3

3A

4

Anode Rod

Hot Water Outlet Nipple

T&P Nipple

T&P Coupling

T&P Relief Valve

High Limit Switch

Surface High Limit Switch

Hex Nut

Lock Washer

Screw

9

10

High Limit Spacer

Cleanout O-Ring

10A Cleanout Gasket (ASME)

11 Cleanout Cover

11A Cleanout Cover (ASME)

12 Cleanout Cover Screw

12A Cleanout Cover Screw (ASME)

13

14

15

Cleanout Access Cover

Brass Drain Valve

Escutcheon

Drain Extender

Thermostat Dial

Screw

Immersion Thermostat

Heating Element

Surface Thermostat Bracket

Surface Thermostat

Surface Thermostat Cover

Item

39

40

41

42

43

34

35

36

37

38

29

30

31

32

33

24

25

26

27

28

44

45

46

47

48

49

50

Description

Lower Control Box Cover

Heating Element Plug

Heating Element Gasket

Cold Water Inlet Nipple

Plastic Snap Bushing

Lower Control Box

Upper Control Box

Terminal Block (Block A)

Terminal Block End (used for Block A)

Terminal Block 2 Pole

Terminal Block 3 Pole

Screw

Fuse Block 2 Pole, Class G

Fuse Block 3 Pole, Class G

Fuse Block 3 Pole, Class J

Contactor 3 Pole

Contactor 4 Pole

Screw

Contactor Coil

Fuse, Class G

Fuse, Class J

Fuse, Class J

Ground Lug Small

Ground Lug Large

Screw

¾” NPT Plug

Transformer - 120V

Glossary of Terms

Term Defi nition

Current

Resistance

Energy

Power

Rate of voltage fl ow

Ability of a device to dissipate power irreversibly

Ability to do work

Energy per unit of time

One Kilowatt (1kW) = 1,000 Watts = 3,412 BTU

DC = Direct Current

AC = Alternating Current

Hz = Hertz

°F = Degrees Fahrenheit

°C = Degree Centigrade

Unit of Measure

Volts

Amperes (amp)

Ohms kW/hr, Joule

Watts, kW, VA

BTUH = British Thermal Units per Hour

PSI = Pounds per Square Inch

GPM = Gallons per Minute

GPH = Gallons per Hour

ECO - Energy Cut Off

NPT - National Pipe Thread

ASME - American Society of Mechanical Engineers

33

34

NOTES

NOTES

35

Madison, Wisconsin

For U.S. and Canada fi eld service, contact your professional installer or local Bock Water Heaters sales representative

Sales/608-227-3311

Fax/608-327-3311

Application & Sizing/608-227-3311

Fax/608-327-3311

Technical Support/888-784-8322

Fax/610-683-9208

Warranty/608-227-3319

Fax/608-327-3300

Email [email protected]

www.bockwaterheaters.com

advertisement

Was this manual useful for you? Yes No
Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Related manuals

Download PDF

advertisement