Sub-Zero UC-24 series Service Manual

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Page 1

Under Counter

(UC-24)

Series

TTeecchhnniiccaall

SSeerrvviiccee MMaannuuaall

Page 2

Electronic Control System

Under Counter (UC-24) Series

3-1

#7003933 - Revision B - November, 2007

ELECTRONIC CONTROL

SYSTEM INFORMATION

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Electronic Control System

Under Counter (UC-24) Series

3-3

#7003933 - Revision B - November, 2007

Figure 3-1. UC-24C Wiring Schematic

YELLOW

(WHEN USED)

CAPACITOR

COMPRESSOR

ORANGE

PURPLE

REF LIGHT SWITCH

ORANGE

WHITE

BLACK

REF FAN MOTOR

OVERLOAD

CONDENSER FAN

RED

RELAY

STARTING

RUNNING

WHITE

PIN 1

THERMISTOR

EVAPORATOR

THERMISTOR CABINET/REF

DISPLAY BOARD

BLUE W/BLACK STRIPE BLUE W/BLACK STRIPE

RED

WHITE

ORANGE W/RED STRIPE

BLUE W/RED STRIPE

PIN 1

YELLOW

ORANGE

BLUE W/WHITE STRIPE

TAN

VALVE

ICEMAKER

BLUE

ICEMAKER

WHITE

FUSE

THERMAL

BLACK

R160 OHMS

YELLOW W/WHITE STRIPE

YELLOW W/BLACK STRIPE

YELLOW W/RED STRIPE

GRAY/WHITE

WHITE

ORANGE

PIN 1

MAIN BOARD

PIN 1

WHITE

REF (TOP) LIGHT

PROTECTOR

COMPRESSOR

MAIN BOARD

MEMBRANE KEYPAD

NEUTRAL

60 CYCLES

HIGH VOLTAGE SCHEMATIC

115 VO LTS

PIN 1

LOW VOLTAGE SCHEMATIC

PIN 1

BLUE W/WHITE STRIPE

THERMISTOR CABINET/FREEZER

R55 OHMS

DEFROST HEATER

REF AIR DUCT BAFFLE

DISPLAY

ELECTRONIC CONTROL SYSTEM OVERVIEW

Below is the wiring schematic for the model UC-24C, illustrating the components of the electronic control system.

• Manual input operations are performed at the control panel (membrane keypad).

• Temperatures and possible problems with the unit will appear in the control panel display.

• Monitoring, regulating and controlling functions take place at the main control board.

The entire electronic control system is described in greater detail on the following pages.

NOTE: For more detailed electrical diagrams refer to the wiring diagram and schematic supplied with the unit.

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Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

Figure 3-2. Main Control Board Layout

Figure 3-3. Main Control Board Summary Table

MAIN CONTROL BOARD LAYOUT AND SUMMARY TABLE

Electrical connection points on the main control board are labeled alphanumerically. These labels correspond with the alphanumeric summary table, located on the wiring diagram. By referencing the summary table, it is possible to identify which components are connected at which points on the main control board. Below is a layout diagram of the main control board, and a copy of a model UC-24C summary table. (See Figures 3-2 & 3-3)

NOTES:

• All components on the control board are non-replaceable. If a problem with the control board is identified, the complete control board must be replaced.

• There is also a small control board in the control panel assembly (Not Shown). All components in the control panel assembly are non-replaceable. If a problem with the control panel is identified, the complete control panel assembly must be replaced.

PIN 1

TERMINAL

J5-1,2 J5-5,6 J5-3,4

CIRCUIT

120 VOLT CIRCUITS

P4 P3 P1

P2 J3-1 J3-2 J3-3 J3-4 J3-5 J3-6 J3-7 J2-1 J2-2 J2-3 J2-4

J5-7 J5-8 J6-1 J6-2 J6-3 J4-1 J4-2 J4-3 J4-4 J4-5 J4-6

COMPRESSOR

DEFROST

FAN 1

ICE

FAN 2

LIGHTS

R DOOR

DEF

ICE

LOW VOLTAGE THERMISTOR CIRCUITS

CAB

CAB EVAP EVAP

N C O

DISPLAY DISPLAY DISPLAY DISPLAY

PIN 1

P2 P1 P3 P4

MAIN CONTROL BOARD SUMMARY

DESCRIPTION

NEUTRAL POWER IN COMPRESSOR DEFROST HEATER EVAPORATOR FAN NOT USED NOT USED NOT USED NOT USED NOT USED LIGHTS

REF DOOR LIGHT SENSE DEFROST SENSOR NOT USED

NOT USED FREEZER COMPARTMENT REF COMPARTMENT EVAPORATOR EVAPORATOR BAFFLE NEUTRAL BAFFLE CLOSE BAFFLE OPEN

DISPLAY WIRING DISPLAY WIRING DISPLAY WIRING DISPLAY WIRING

FUNCTION

NEUTRAL INTO BOARD POWER INTO BOARD POWERS COMPRESSOR AND CONDENSER FAN POWERS DEFROST CIRCUIT POWERS EVAPORATOR FAN

POWERS LIGHTS

SENSES IF LOWER DOOR OPEN SENSES WHEN DEFROST HEATER SHUTS OFF

SENSES FREEZER CABINET TEMP SENSES REF CABINET TEMPERATURE SENSES EVAPORATOR TEMPERATURE SENSES EVAPORATOR TEMPERATURE BAFFLE NEUTRAL PULSED TO CLOSE NEUTRAL PULSED TO OPEN NEUTRAL

12VDC POWER SUPPLY FOR DISPLAY BOARD SERIAL DATA RECEIVE SERIAL DATE TRANSMIT GROUND FOR DISPLAY BOARD POWER SUPPLY

PIN 1

COLOR

WHITE BLACK

PURPLE

BLUE

RED

YELLOW

ORANGE

GRAY/WHITE

BLUE/WHITE BLUE/BLACK

ORANGE/RED

BLUE/RED

YELLOW/RED YELLOW/BLACK YELLOW/WHITE

WHITE

RED YELLOW ORANGE

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Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

CONTROL PANEL LAYOUT

NOTES:

• The LCD in these units is not back lit.

• Though there is a Bell icon on the LCD, there is no alarm system in the Under Counter Series. The Bell icon will only be observed during Diagnostic Mode, Manual Component Activation Mode and as a Temperature Log Event Indicator.

LCD

(GÖRÜNTÜ PANELi)

FREEZER AYAR TUSLARI

FRESH FOOD AYAR TUSLARI

Figure 3-4. UC-24C Kumanda Paneli Görünümü

LCD

(GÖRÜNTÜ PANELi)

FRESH FOOD AYAR TUSLARI

AÇ/KAPA TUSU

Figure 3-5. UC-24B, UC-24R, UC-24RO Kumanda Paneli Görünümü

AÇ/KAPA TUSU

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Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

Adjusting Set-Point (Temperature Adjustments)

To adjust set-points, press WARMER or COLDER keys on control panel in multiple key strokes

until the desired set-

point is achieved. One key stroke equals one degree change (Fahrenheit or Celsius). (See Figure 3-7)

NOTES:

• Temperature ranges are -5°F (-21°C) to +5°F (-15°C) in a freezer zone, +34°F (+1°C) to +45°F (+7°C) in a refrigerator zone, with initial set-points of 0°F (-18°C) and +38°F (+3°C), respectively.

• The initial stroke of the WARMER or COLDER keys will change previous set-point by one degree.

• The set-point will be displayed on the LCD for ten (10) seconds after the last WARMER or COLDER key stroke.

After the ten (10) second delay, the zone temperature will be displayed. As the zone temperature changes, the temperature displayed on the LCD will change by no more than one (1) degree per minute.

Sekil 3-6. Cihazin çalistirilmasi ve durdurulmasi için POWER tusu kullanilir.

Sekil 3-7. Ayar yapmak için WARMER ya da COLDER tuslarini kullaniniz.

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Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

UNIQUE ELECTRONIC CONTROL INPUT OPERATIONS

The following pages describe unique input operations that a customer typically would not perform every day. The input operations described here are Temperature Unit Selection Mode, Sabbath Mode and Showroom Mode.

Temperature Units Selection (Selecting Fahrenheit or Celsius Display - UC-24C Only)

NOTE: For Temperature Unit Selection in the models UC-24R, UC-24RO and UC-24B, see next page.

The electronic control is initially set to display temperature in Fahrenheit (°F) units of measure. Units of measure can be converted from °F to °C (Celsius), and/or back again. This operation is called Temperature Units Selection.

NOTE: Temperature Units Selection must be performed within the first (1) minute of switching the unit ON.

To convert units of measure in a model UC-24C, first press and hold the Freezer

WARMER key and the POWER

key (this actually initiates Temperature Log Recall Mode, which is covered fully, later in this section). (See Figure 3-

8) Then, press and hold the Freezer

WARMER and COLDER keys for fifteen (15) seconds and “ °C “ will appear on the LCD indicating temperatures will now be displayed in Celsius units of measure. (See Figures 3-9) To convert back to Fahrenheit units of measure, repeat the steps above.

NOTE: Temperature Units Selection Mode will end ten (10) seconds after the last key stroke.

Figure 3-9. (Model UC-24C) Convert Temperature Units of Measure

Press and Hold the Freezer

WARMER and COLDER Keys for 15 Seconds

Press & Hold

for 15 Seconds

Figure 3-8. (Model UC-24C) Initiate TLR Mode First (within first minute of switching unit ON)

Press and Hold Freezer WARMER Key, Then Press POWER Key

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Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

Temperature Units Selection (Selecting Fahrenheit or Celsius Display - UC-24B, UC-24R, UC-24RO Only)

NOTE: For Temperature Unit Selection in the model UC-24C, see previous page.

NOTE: Temperature Units Selection must be performed within the first (1) minute of switching the unit ON.

To convert units of measure in these models, first press and hold the WARMER key and the POWER key (this actually initiates Temperature Log Recall Mode, which is covered fully, later in this section). (See Figure 3-10) Then, press and hold the WARMER and COLDER keys for fifteen (15) seconds and “ °C “ will appear on the LCD indicating temperatures will now be displayed in Celsius units of measure. (See Figures 3-11) To convert back to Fahrenheit units of measure, repeat the steps above.

NOTE: Temperature Units Selection Mode will end ten (10) seconds after the last key stroke.

Figure 3-11. (Models UC-24B, UC-24R, UC-24RO) Convert Temperature Units of Measure

Press and Hold the Refrigerator

WARMER and COLDER Keys for 15 Seconds

Fig. 3-10. (Models UC-24B, UC-24R, UC-24RO) Initiate TLR Mode First (within

first minute of switching ON)

Press and Hold WARMER Key, Then Press POWER Key

Press & Hold

for 15 Seconds

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Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

Sabbath Mode

Sabbath Mode was incorporated into the electronic control system for the observance of certain religious days. Initiating Sabbath Mode disables the LCD and lighting system.

To initiate Sabbath Mode, the unit must first be switched OFF using the POWER key (See Figure 3-12), then press and hold the POWER key for approximately ten (10) seconds, until the LCD and lights switch OFF (See Figure 3-

13). To return to normal operation, press and release the POWER key.

NOTES:

• During Sabbath Mode, the evaporator fan may function when the door is open.

• During Sabbath Mode, the LCD is disabled and set-points cannot be changed.

• The icemaker in the model UC-24C is fed direct from L1, so icemaker operation is not affected by Sabbath Mode.

• The Model UC-24B utilizes a rocker switch at the top of the compartment for controlling the accent lights. This

accent lighting system is not affected by Sabbath Mode because its power comes direct from L1.

Figure 3-13. After Unit is Switched OFF, Press and Hold POWER Key for 10 Seconds

Figure 3-12. To Enter Sabbath Mode, Switch Unit OFF First

Press and hold for 10 seconds

Press and release, switching unit OFF

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Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

Showroom Mode

Showroom Mode was incorporated into the electronic control system so these appliances could be displayed in a showroom setting. When in Showroom Mode, all cooling functions are disabled, but the lighting system and LCD remain active.

To initiate Showroom Mode, the unit must first be switched OFF using the POWER key (See Figure 3-14). With the unit switched OFF, press and hold either pair of WARMER and COLDER keys, then press the POWER key, then release all three keys (See Figure 3-15).

To return unit to normal operating condition, repeat the steps above.

NOTES:

• Always check set-points after returning unit to normal operating condition.

• It is possible to determine if a unit is in Showroom Mode by initiating Diagnostic Mode. If “Sr” is observed in the

left temperature display area during Diagnostic Mode, the unit is in Showroom mode. Initiating Diagnostic Mode is covered later in this section.

Figure 3-15. After Unit is Switched OFF, Press and Hold the WARMER and COLDER Keys,

Then Press the POWER Key

Figure 3-14. To Enter (or Exit) Showroom Mode, Switch Unit OFF First

Press and release, switching unit OFF

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Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

FUNCTIONS OF ELECTRONIC CONTROL SYSTEM

The following few pages explain monitoring, regulating and controlling functions of the electronic control system.

Display Zone Temperatures

The temperature signals from the thermistors in the refrigerator and freezer compartments are monitored by the microprocessor and then displayed on the LCD. Though the compartment air temperature does fluctuate, the LCD displays the “average” temperature (See Figure 3-16).

NOTE: If zone temperature changes, temperature display will change by one degree per minute.

Figure 3-16. Display Zone Temperatures

“average” temperature displayed

Figure 3-17. UC-24B Signal Trace Schematic (High Voltage) of Lighting System

RELAY

STARTING

(WHEN

USED)

CAPACITOR

COMPRESSOR

REF LIGHT

SWITCH

WHITE

BLACK

PROTECTOR

ORANGE

PURPLE

ORANGE

PIN 1

YELLOW

MAIN BOARD

PIN 1

ORANGE

PIN 1

WHITE

REF (TOP)

LIGHT

REF FAN MOTOR

OVERLOAD

CONDENSER FAN

RED

COMPRESSOR

RUNNING

WHITE

NEUTRAL

HIGH VOLTAGE SCHEMATIC

115 VOLTS 60 CYCLES

LIGHTS

PINK

WHITE

REF LIGHT

SWITCH

LIGHT TUBE SWITCH

(UC-24B ONLY)

Supply Power to the Lighting System

Power is supplied to the lighting system through the control board when the unit is switched ON by pressing the POWER key. With the door open, the light switch allows power to the lights. (See Figure 3-17).

NOTES:

• Power to the lights is monitored by the microprocessor to control evaporator fan motor operation.

• When in Sabbath Mode, the lighting system is disabled. Sabbath Mode was covered earlier in this section.

• The accent lighting system in the model UC-24B is fed direct from L-1.

2. Power supplied to lighting system unless unit is switched OFF, or in Sabbath Mode.

NOTE: Light switch position monitored to control fan operation.

1. Power supplied to control board.

NOTE: Accent lighting system in UC-24B is fed direct from L1.

Page 12

Regulate Freezer Zone Temperature (UC-24C Only)

When the freezer compartment thermistor detects high off-set temperature, calling for cooling, the compressor and condenser fan motor are energized, as well as the evaporator fan motor. (See Figure 3-18)

If the door is opened while the evaporator fan is operating, the microprocessor will detect the power signal to the lights and cut power to the fan.

NOTES:

• When the freezer compartment calls for cooling after a defrost, the evaporator fan will not be allowed to run until the thermistor on the evaporator drops to 35°F (2°C).

• If compartment tem-

perature exceeds either high or low offset the temperature display will change by one degree (1°) per minute.

• If freezer compartment thermistor is faulty, compressor operation defaults to twenty (20) minutes ON, twenty (20) minutes OFF cycling; EE appears in left of LCD; SERVICE flashes and Error Code 07 is logged.

• If evaporator thermistor is faulty, the compressor will be energized after the dwell time and the evaporator fan will be energized 3 minutes later; SERVICE flashes and Error Code 08 is logged.

• When in Sabbath Mode, the freezer compartment thermistor still controls compressor operation, except there is a random fifteen (15) to twenty-five (25) second delay before the compressor is energized.

Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

Figure 3-18. UC-24C Signal Trace - Regulate Freezer Zone Temperature

1. Freezer compartment thermistor at high off-set temp. calling for cooling.

4. Evap fan energized.

2. Compressor and condenser fan energized.

3. Door is closed, so no power to lights. This is monitored via the orange wire.

LOW VOLTAGE SCHEMATIC

REF AIR DUCT BAFFLE

YELLOW W/WHITE STRIPE

YELLOW W/BLACK STRIPE

YELLOW W/RED STRIPE

PIN 1

MEMBRANE KEYPAD

MAIN BOARD

PIN 1

THERMISTOR CABINET/FREEZER

DISPLAY

DISPLAY BOARD

THERMISTOR CABINET/REF

THERMISTOR

EVAPORATOR

PIN 1

WHITE

BLUE W/RED STRIPE

ORANGE W/RED STRIPE

BLUE W/WHITE STRIPE BLUE W/WHITE STRIPE

BLUE W/BLACK STRIPE BLUE W/BLACK STRIPE

YELLOW

RED

HIGH VOLTAGE SCHEMATIC

115 VOLTS 60 CYCLES

ORANGE

PIN 1

ORANGE

PIN 1

MAIN BOARD

PIN 1

GRAY/WHITE

PIN 1

NEUTRAL

WHITE

BLACK

PURPLE

BLUE

RED

YELLOW

ORANGE

REF LIGHT SWITCH

GRAY/WHITE

DEFROST HEATER

REF (TOP) LIGHT

OVERLOAD

PROTECTOR

CONDENSER FAN

R55 OHMS

COMPRESSOR

REF FAN MOTOR

RUNNING

CAPACITOR

COMPRESSOR STARTING RELAY

WHITE

(WHEN USED)

WHITE

ORANGE

BLACK

THERMAL

FUSE

ICEMAKER

WHITE

TAN

ICEMAKER

VALVE

R160 OHMS

WHITE

Page 13

Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

Regulate Refrigerator Zone Temperature (UC-24C Only)

When the thermistor in refrigerator compartment reaches high off-set temperature, calling for cooling, the microprocessor sends an 18 Volt pulse signal to the air baffle control to open, regardless of operational state of the compressor. When calling for cooling, the microprocessor repeats sending a pulse signal every five (5) minutes to the air baffle control to open. (See Figure 3-19)

When the refrigerator compartment thermistor detects low off-set temperature, the microprocessor sends an 18 Volt pulse signal to the air baffle control to close. Whenever the refrigerator compartment is not calling for cooling, the microprocessor repeats sending a pulse signal every five (5) minutes to the air baffle control to close.

NOTES:

• If compartment temperature exceeds either high or low offset the temperature display will change by one degree (1°) per minute.

• If refrigerator compartment thermistor is faulty, air baffle defaults to twenty (20) minutes open, forty (40) minutes closed cycling; EE appears in right of LCD; SERVICE flashes and Error Code 05 is logged.

• When in Sabbath Mode, refrigerator compartment thermistor still controls baffle operation except there is a random fifteen (15) to twenty-five (25) second delay before the baffle is energized.

Figure 3-19. UC-24C Signal Trace - Regulate Refrigerator Zone

1. Refrigerator compartment thermistor at high off-set temp. calling for cooling.

2. Pulse signal to air baffle control every 5 minutes.

LOW VOLTAGE SCHEMATIC

MEMBRANE KEYPAD

PIN 1

THERMISTOR CABINET/FREEZER

REF AIR DUCT BAFFLE

DISPLAY

DISPLAY BOARD

THERMISTOR CABINET/REF

THERMISTOR

EVAPORATOR

PIN 1

YELLOW W/WHITE STRIPE

YELLOW W/BLACK STRIPE

YELLOW W/RED STRIPE

WHITE

BLUE W/RED STRIPE

ORANGE W/RED STRIPE

BLUE W/WHITE STRIPE BLUE W/WHITE STRIPE

BLUE W/BLACK STRIPE BLUE W/BLACK STRIPE

PIN 1

MAIN BOARD

PIN 1

ORANGE

YELLOW

RED

PIN 1

HIGH VOLTAGE SCHEMATIC

ORANGE

GRAY/WHITE

115 VOLTS 60 CYCLES

NEUTRAL

WHITE

PIN 1

MAIN BOARD

PIN 1

WHITE

BLACK

PURPLE

BLUE

YELLOW

ORANGE

REF LIGHT SWITCH

GRAY/WHITE

RED

OVERLOAD

PROTECTOR

CONDENSER FAN

DEFROST HEATER

R55 OHMS

REF (TOP) LIGHT

COMPRESSOR

REF FAN MOTOR

RUNNING

CAPACITOR

(WHEN USED)

COMPRESSOR STARTING RELAY

WHITE

ORANGE

BLACK

THERMAL

FUSE

ICEMAKER

WHITE

TAN

ICEMAKER

VALVE

R160 OHMS

WHITE

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Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

Regulate Refrigerator Zone Temperature (UC-24B, UC-24R, UC-24RO)

When the refrigerator compartment thermistor detects high off-set temperature, calling for cooling, the evaporator fan is energized, but the compressor and condenser fan are not allowed to run until the thermistor on the evaporator rises to 38°F (3°C). (See Figure 3-20)

If the door is opened while the evaporator fan is operating, the microprocessor will detect the power signal to the lights and cut power to the fan.

NOTES:

• If compartment temperature exceeds either high or low offset the temperature display will change by one degree (1°) per minute.

• If refrigerator compartment thermistor is faulty, compressor operation defaults to twenty (20) minutes ON, forty (40) minutes OFF cycling; EE appears in right of LCD; SERVICE flashes and Error Code 05 is logged.

• If evaporator thermistor is faulty, the compressor will not energize until zone air temperature exceeds high offset by 5°F (3°C); SERVICE flashes and Error Code 06 is logged.

• When in Sabbath Mode, the refrigerator compartment thermistor still controls compressor operation, except there is a random fifteen (15) to twentyfive (25) second delay before the compressor is energized.

Figure 3-20. UC-24B Signal Trace - Regulate Refrigerator Zone

1. Compartment thermistor at high off-set temp. calling for cooling.

4. Evap Thermistor above 38°F (3°C).

3. Evap fan energized.

2. Door is closed, so no power to lights. This is monitored via the orange wire.

5. Compressor and condenser fan energized.

LOW VOLTAGE SCHEMATIC

DISPLAY

DISPLAY BOARD

HIGH VOLTAGE SCHEMATIC

ORANGE

PIN 1

MAIN BOARD

PIN 1

WHITE

BLACK

MEMBRANE KEYPAD

115 VOLTS 60 CYCLES

YELLOW

PIN 1

THERMISTOR EVAPORATOR

THERMISTOR REFRIGERATOR

NEUTRAL

WHITE

PURPLE

RED

ORANGE

REF LIGHT

SWITCH

ORANGE

YELLOW

RED

WHITE

BLUE W/RED STRIPE

ORANGE W/RED STRIPE

BLUE W/BLACK STRIPE BLUE W/BLACK STRIPE

REF LIGHT

SWITCH

PINK

LIGHT TUBE SWITCH

(UC-24B ONLY)

LIGHTS

OVERLOAD

REF (TOP)

LIGHT

PROTECTOR

CONDENSER FAN

COMPRESSOR

REF FAN MOTOR

WHITE

MAIN BOARD

PIN 1

RUNNING

CAPACITOR

COMPRESSOR STARTING RELAY

PIN 1

WHITE

(WHEN USED)

PIN 1

ORANGE

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Electronic Control System

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

Minimize Condensation on Refrigerator Door Glass (UC-24B Only)

To help minimize the formation of condensation, or fog, on the door glass of the model UC-24B, the microprocessor detects when the refrigerator door is opened, via the light switch, then when the door closes, the evaporator fan is energized for five (5) minutes, regardless of compressor operational state. This draws any warmer moist air away from the door glass. (See Figure 3-21)

NOTE: The evaporator fan also cycles with the compressor.

Figure 3-21. UC-24B Signal Trace Schematic - Evaporator Fan Operation in Glass Door Unit

2. Evap fan energized for 5 minutes.

1. Door is opened, then closed. This is monitored via the orange wire.

HIGH VOLTAGE SCHEMATIC

ORANGE

PIN 1

MAIN BOARD

PIN 1

ORANGE

PIN 1

115 VOLTS 60 CYCLES

WHITE

BLACK

NEUTRAL

PURPLE

RED

REF LIGHT

LIGHT TUBE SWITCH

(UC-24B ONLY)

WHITE

SWITCH

OVERLOAD

PROTECTOR

CONDENSER FAN

PINK

LIGHTS

COMPRESSOR

REF FAN MOTOR

WHITE

RUNNING

CAPACITOR

COMPRESSOR STARTING RELAY

WHITE

(WHEN USED)

YELLOW

ORANGE

REF LIGHT

SWITCH

REF (TOP)

LIGHT

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Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

Monitor and Control Freezer “Adaptive Defrost” (UC-24C Only)

Initially, the compressor will cycle-run for 12 hours, after which the microprocessor sends a signal to the defrost relay on the control board to close. This supplies power to the defrost heater. At the same time the compressor, condenser fan and evaporator fan are switched off.

With the “Adaptive Defrost” technique, the length of time that the defrost heater stays on to open the defrost terminator bimetal (70°F/21°C), is observed by the microprocessor via the grey w/white stripe wire to J2.

The microprocessor then determines the number of hours before the next defrost. If the heater stays on for a shorter time than specified, the microprocessor increases the next defrost interval. If the heater stays on longer than specified, the electronic control decreases the next defrost interval. (See Figure 3-22) This is an ongoing process whereby the defrost time and the defrost interval will vary by unit use.

NOTES:

• A five (5) minute time delay/dwell follows all defrosts. At the end of the five (5) minute dwell, the compressor and condenser fan are energized, but the evaporator fan will not be energized until the evaporator temperature falls below 35°F (2°C).

• The minimum defrost interval is six (6) hours of compressor run time; the maximum defrost interval is eighty (80) hours of compressor run time; the maximum defrost duration is twenty-five (25) minutes plus five (5) minute dwell.

• If the grey w/white wire defrost sensing line is open, defrost operation defaults to twenty-five (25) minute defrost time and 6 hour build time, and Error Code 22 is logged. If the evaporator thermistor detects an underheat or overheat situation at the same time, Error Codes 20 or 23 will be registered, respectively.

• During defrost, the display temperature is locked.

Figure 3-22. UC-24C Signal Trace Schematic - Adaptive Defrost

1. Compressor runs 12 hours, then switched off.

2. Defrost circuit energized.

3. Terminator opens at 70°F (21°C)

4. Defrost duration observed, interval between next defrost adjusted.

HIGH VOLTAGE SCHEMATIC

ORANGE

PIN 1

MAIN BOARD

PIN 1

GRAY/WHITE

PIN 1

ORANGE

115 VOLTS 60 CYCLES

NEUTRAL

WHITE

BLACK

PURPLE

BLUE

RED

YELLOW

ORANGE

REF LIGHT SWITCH

THERMAL

FUSE

BLACK

GRAY/WHITE

CONDENSER FAN

DEFROST HEATER

R55 OHMS

REF (TOP) LIGHT

ICEMAKER

WHITE

TAN

OVERLOAD

PROTECTOR

COMPRESSOR

REF FAN MOTOR

ICEMAKER

VALVE

R160 OHMS

WHITE

RUNNING

CAPACITOR

COMPRESSOR STARTING RELAY

WHITE

(WHEN USED)

WHITE

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Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

Monitor and Control Refrigerator Fan-Assisted, Off-Cycle Defrost (UC-24B, UC-24R, UC-24RO)

Temperature signals from the compartment and evaporator thermistor’s are observed by the microprocessor. During off cycle defrost, if a refrigerator compartment temperature reaches high offset (calling for cooling) before evaporator temperature rises to 38°F (3°C), no power will be supplied to the compressor. But, the evaporator fan will be switched ON. Once the evaporator temperature reaches 38°F (3°C), normal cooling functions begin. (See Figure 3-

23).

NOTES:

• If evaporator thermistor is faulty, the compressor will not energize until zone air temperature exceeds high offset by 5°F (3°C); SERVICE flashes and Error Code 06 is logged.

• When in Sabbath Mode, the refrigerator compartment thermistor still controls compressor operation, except there is a random fifteen (15) to twenty-five (25) second delay before the compressor is energized.

Figure 3-23. UC-24B Signal Trace - Refrigerator Fan Assisted Off-Cycle Defrost

1. Compartment thermistor at high off-set temp. calling for cooling.

4. Evap Thermistor below 38°F (3°C).

3. Evap fan energized.

2. Door is closed, so no power to lights. This is monitored via the orange wire.

5. Compressor and condenser fan stay OFF until evap rises to 38°F (3°C).

PIN 1

LOW VOLTAGE SCHEMATIC

DISPLAY

MEMBRANE KEYPAD

DISPLAY BOARD

PIN 1

THERMISTOR EVAPORATOR

THERMISTOR REFRIGERATOR

PIN 1

MAIN BOARD

ORANGE

YELLOW

BLUE W/RED STRIPE

ORANGE W/RED STRIPE

BLUE W/BLACK STRIPE BLUE W/BLACK STRIPE

WHITE

RED

PIN 1

HIGH VOLTAGE SCHEMATIC

ORANGE

PIN 1

MAIN BOARD

PIN 1

ORANGE

PIN 1

WHITE

BLACK

YELLOW

115 VOLTS 60 CYCLES

NEUTRAL

PURPLE

ORANGE

REF LIGHT

LIGHT TUBE SWITCH

(UC-24B ONLY)

WHITE

RED

SWITCH

REF (TOP)

LIGHT

OVERLOAD

PROTECTOR

CONDENSER FAN

PINK

LIGHTS

COMPRESSOR

REF FAN MOTOR

WHITE

RUNNING

CAPACITOR

COMPRESSOR STARTING RELAY

WHITE

(WHEN USED)

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Monitor Compressor Run Duration, Displays If Service is Needed

The microprocessor observes the state of the compressor relay to determine the length of compressor run time (See Figure 3-24). If the compressor runs 100% (Freezer = 6 hours, Refrigerator = 4 hours), an error code is logged (EC 40, or EC 50, respectively), and defrost will be initiated, but SERVICE will not

flash.

If several 100% compressor run periods occur, and the door was not opened during the last excessive compressor run period, and the temperature in the zone is not able to fall half way between the set point and the low off-set, then SERVICE will flash (See Figure 3-25).

NOTES:

• After the problem is corrected, the error code must be cleared from memory, otherwise a non-flashing “SERVICE” will display constant on the LCD. See “Clearing Non-Flashing “SERVICE” and Error Codes” later in this section.

• If the unit is ever switched OFF then back ON, the compressor will not energize for at least three (3) minutes. This three (3) minute minimum OFF time is used to protect the compressor and its electricals.

Figure 3-25. Service Flashing if several 100% compressor run periods occurred, the door was not opened

during last excessive run period, and temperature is not able to fall half way between set point & low off-set.

Figure 3-24. UC-24C Signal Trace Schematic - Compressor Run

Compressor relay closed, allowing power to compressor. This is observe by microprocessor.

HIGH VOLTAGE SCHEMATIC

ORANGE

PIN 1

MAIN BOARD

PIN 1

ORANGE

GRAY/WHITE

115 VOLTS 60 CYCLES

WHITE

BLACK

PURPLE

BLUE

YELLOW

NEUTRAL

RED

ORANGE

REF LIGHT SWITCH

THERMAL

FUSE

BLACK

GRAY/WHITE

WHITE

ICEMAKER

OVERLOAD

PROTECTOR

CONDENSER FAN

DEFROST HEATER

R55 OHMS

REF (TOP) LIGHT

WHITE

TAN

COMPRESSOR

REF FAN MOTOR

ICEMAKER

VALVE

R160 OHMS

WHITE

RUNNING

CAPACITOR

(WHEN USED)

COMPRESSOR STARTING RELAY

WHITE

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POSSIBLE ERROR INDICATORS

The diagrams on this page illustration what a customers may see on the LCD if a problem/error exists with the unit.

NOTE: Error code must be cleared from memory after problems are corrected, otherwise a non-flashing “SERVICE” will display constant on the LCD. See “Clearing Non-Flashing “SERVICE” and Error Codes” later in this section.

Figure 3-27.

“EE” Displayed at Right & “SERVICE” Flashing = Refrigerator Compartment Thermistor (or its Wiring) Fault

Figure 3-26.

“EE” Displayed at Left & “SERVICE” Flashing = Freezer Compartment Thermistor (or its Wiring) Fault

Figure 3-29.

Service Flashing = Several 100% run periods, the door was not open during last 100% run period, and zone

temperature not able to fall half way between set point and low off-set.

Figure 3-30.

“SERVICE” Steady, not Flashing = Error Codes Observed in Diagnostic Mode, but not Cleared

Figure 3-28.

Service Flashing = Evaporator Thermistor (or its Wiring) Fault

Figure 3-31.

“ - - ” (Double Dashes) Displayed = Model Configuration was not Performed

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Models UC-24R, UC-24RO

THERMISTOR LOCATION CODE

Refrigerator Compartment r

Evaporator E

ELECTRONIC CONTROL TROUBLESHOOTING INPUT OPERATIONS

The following few pages explain troubleshooting input operations performed at the control panel. The input operations described are Diagnostic Mode, Manual Component Activation Mode and Temperature Log Recall.

Diagnostic Mode (a.k.a. Actual Temperature Display Mode)

Initiating Diagnostic Mode allows the Service Technician to observe real-time temperature readings from all thermistors without temperature averaging.

To initiate Diagnostic Mode, the unit must be ON, then press and hold either

COLDER key, and press the POWER key, then release both keys (See Figure 3-32). The left display area will show the real-time temperature of the thermistor, the right display area will show the thermistor location code, and all LCD indicators will illuminate. Pressing either

COLDER key while in Diagnostic Mode will toggle forward (increment) to the next thermistor location (See Figures 3-33 & 3-34), while pressing either WARMER key will toggle backward (decrement) to the previous thermistor location.

NOTE: If the COLDER and POWER keys are pressed and held for ten (10) seconds, Manual Component Activation Mode will be initiated (this is covered later in the section).

NOTE: Diagnostic Mode will end twenty (20) seconds after the last key stroke.

Figure 3-32. Initiate Diagnostic Mode - Press and Hold Either

COLDER Key, Then POWER Key

(“F” Indicates Freezer Zone/Compartment)

Figure 3-33. Toggle Through Temperature Readings - Press Either COLDER Key

(“r” Indicates Refrigerator Zone/Compartment)

Figure 3-34. Toggle Through Temperature Readings - Press Either COLDER Key

(“E” Indicates Evaporator)

Model UC-24C

THERMISTOR LOCATION CODE

Freezer Compartment F

Refrigerator Compartment r

Evaporator E

Model UC-24B

THERMISTOR LOCATION CODE

Beverage Compartment r

Evaporator E

THERMISTOR LOCATION CODE TABLES

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Figure 3-35. “EE” Observed in Diagnostic Mode = Thermistor Fault in Location Indicated by Code

Figure 3-36. “Sr” Observed While in Diagnostic Mode = Unit is in Showroom Mode

If “Sr” is observed at left display area during Diagnostic Mode, the unit is in Showroom Mode, which was explained earlier in this section (See Figure 3-36).

If “EC” is observed in the right display area during Diagnostic Mode, the numbers at left are “Error Codes” (See Figure 3-37). Error Codes indicate problems registered by specific components. If error codes are registered, they will appear before temperature readings and can be toggled through with the temperature readings as described on the previous page. (See Error Code Table below and instructions on clearing Error Codes on next page.)

Figure 3-37. “EC” Observed While in Diagnostic Mode = Error Code

(See table below & how to clear Error Codes on next Page)

Error Code Table

CODE INDICATION

05 Refrig. cabinet thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s

06 Refrig. evaporator thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s

07 Freezer cabinet thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s

08 Freezer evaporator thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s

20 Defrost under-heat with no voltage feedback through Gray/White wire at defrost start

21 Defrost overheat

22 No voltage feedback through Gray/White wire at defrost start

23 Defrost overheat with no voltage feedback through Gray/White wire at defrost start

24 Defrost under-heat

30 NA

40 Excessive Freezer Compressor Run (UC-24C Only)

50 Excessive Refrigerator Compressor Run (UC-24B, UC-24R and UC-24RO Only)

Diagnostic Mode Indicators

If “EE” is observed in left display area during Diagnostic Mode, the thermistor in that location is open or shorted, or there is a break in that thermistor’s wiring (See Figure 3-35).

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Clearing Non-Flashing “SERVICE” and Error Codes

If Error Codes are observed in Diagnostic Mode, a non-flashing

SERVICE icon will appear on the LCD when Diagnostic Mode ends, indicating error codes are still stored (See Figure 3-38). To clear a non-flashing SERVICE icon and the error codes, the problem must be corrected and the unit must be ON, then:

• On a model UC-24C: Press the Freezer

WARMER and COLDER keys for fifteen (15) seconds, and the error

codes are cleared. (See Figure 3-39)

• On a model UC-24B, UC-24R or UC-24RO: Press the Refrigerator

WARMER and COLDER keys for fifteen (15)

seconds, and the error codes are cleared. (See Figure 3-40)

Figure 3-38. Non-flashing SERVICE after Diagnostic Mode = Error Codes are Stored

Figure 3-39. (Model UC-24C) Clear Non-Flashing SERVICE.

With Unit ON, Press and Hold the Freezer WARMER and COLDER Keys for 15 Seconds

Figure 3-40. (Model UC-24B, UC-24R, UC-24RO) Clear Non-Flashing SERVICE.

With Unit ON, Press and Hold the Refrigerator

WARMER and COLDER Keys for 15 Seconds

UC-24C:

Press & Hold

for 15 Seconds

UC-24R, UC-24RO, UC-24B:

Press & Hold

for 15 Seconds

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Figure 3-41. (Model UC-24C) Initiate Manual Component Activation Mode (Freezer Zone Shown) -

Press and Hold Freezer COLDER Key and POWER Key for 10 Seconds

Manual Component Activation Mode

Manual Component Activation Mode energizes the cooling system for five (5) minutes, allowing a Service Technician to check for proper voltage readings at activated components without having to wait for the zone to call for cooling.

To initiate Manual Component Activation Mode the unit must be ON, then press and hold the desired COLDER key and the POWER key for ten (10) seconds (See Figures 3-41 and 3-42). All cooling functions for that zone will begin and the zone compartment temperature will be displayed in the left display area of the LCD, with the right display area showing the thermistor location.

NOTES:

• If a COLDER and the POWER keys are pressed and held for less than

ten (10) seconds, Diagnostic Mode will be

initiated. This was covered earlier in the section.

• In the model UC-24C, if the refrigerator

COLDER key and POWER key are pressed for ten (10) seconds, the baffle control will energize, but the compressor, condenser fan motor and evaporator fan motor will switch to OFF mode.

• It is possible to toggle through the other temperature readings as in Diagnostic Mode, but in this case the temper-

ature readings will last for five (5) minutes rather than twenty seconds.

•The compressor overload could prevent the compressor from energizing.

• Manual Component Activation Mode will end five (5) minutes after it is initiated. It is possible to end this five (5)

minute run time and return to normal operation by pressing the POWER key. If this is done, note that the electronic control will observe a three (3) minute minimum compressor OFF time when the unit is switched back ON. This is to protect the compressor and its electricals.

Press and hold for 10 seconds

Figure 3-42. (Models UC-24B, UC-24R, UC-24RO) Initiate Manual Component Activation Mode -

Press and Hold COLDER Key and POWER Key for 10 Seconds

Press and hold for 10 seconds

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Temperature Log Recall Mode

The electronic control system is equipped with a temperature history data storage system. This system logs/stores the average temperature of each individual thermistor every two hours, along with any event indicators (explained later in this section), that may have occurred. These two-hour periods are referred to as “indexes”. Up to 168 indexes can be stored for each compartment, making it possible to observe the preceding fourteen days of the unit’s temperature history (each index equals 2 hour temperature average; 2 hours X 168 indexes = 14 days). After 168 indexes are stored, each new index will bump the oldest index. Index number “1” being the most recent two-hour temperature average and index number “168” being the oldest. Accessing this temperature history data so it can be viewed on the LCD is accomplished by initiating Temperature Log Recall Mode.

There are two ways to initiate Temperature Log Recall Mode. One allows viewing of compartment temperature history only (see below), the other allows viewing of compartment temperature history and/or evaporator temperature history (see following page).

Initiate Temperature Log Recall Mode To View Compartment Temperature History Only: Begin with the unit ON. Now, press and hold the desired compartment WARMER key, then press the POWER key, then release both keys (See Figure 3-43). The left display area on the LCD will show average compartment temperature and in the right display area will be the index number. The first index number will be “1”, indicating the most recent two-hour temperature average. The right display area will also flash the thermistor location code at 3 second intervals (See Figure 3-44).

Figure 3-43. Initiate Temperature Log Recall Mode To View Compartment Temperature History Only -

Press and Hold Desired

WARMER Key, Then Press POWER Key

Figure 3-44. Thermistor Location Code Flashes Every 3 Seconds

Figure 3-45. Toggle Up (Increment) Through Indexes - Press WARMER Key in Consecutive Key Strokes

Figure 3-46. Toggle Down (Decrement) Through Indexes - Press COLDER Key in Consecutive Key Strokes

To toggle up (increment) through the indexes (from 1 to 168), press the same WARMER key in multiple key strokes (See Figure 3-45). To toggle down (decrement) through the indexes (from 168 to 1), press the corresponding COLDER key in multiple key strokes (See Figure 3-46).

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Figure 3-49. Initiate Temperature Log Recall Mode To View Temperature History -

Press and Hold POWER key first, then WARMER Key

Figure 3-47. Initiate Diagnostic Mode - Press and Hold Either COLDER Key, then the POWER Key

Figure 3-48. Toggle Through Readings - Press COLDER or WARMER Key Until Desired Thermistor

Temperature is Displayed

Initiate Temperature Log Recall Mode To View Compartment and Evaporator Temperature History: To view compartment and/or evaporator temperature history, begin with the unit ON and in Diagnostic Mode (See Figure 3-

47). While in Diagnostic Mode, toggle through the readings until the desired thermistor temperature is displayed on the LCD (See Figure 3-48). Now, press and hold the POWER key first, then the WARMER key, then release both keys (See Figure 3-49). The left display area on the LCD will show average temperature and in the right display area will be the index number “1” indicating the most recent two-hour temperature average. The right display area will also flash the thermistor location code at 3 second intervals (See Figure 3-50).

Figure 3-50. Thermistor Location Code Flashes Every 3 Seconds

Figure 3-51. Toggle Up Through Indexes - Press WARMER Key in Consecutive Key Strokes

Figure 3-52. Toggle Down Through Indexes - Press COLDER Key in Consecutive Key Strokes

To toggle up

(increment) through the indexes (from 1 to 168), press the same WARMER key in multiple key strokes

(See Figure 3-51). To toggle down

(decrement) through the indexes (from 168 to 1), press the corresponding

COLDER key in multiple key strokes (See Figure 3-52).

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Figure 3-54. SERVICE Illuminates -

Indicates Unit was switched OFF During that Index Period by Pressing POWER Key

Figure 3-55. Bell Illuminates - Indicates Power Failure / Interruption During that Index Period

NOTES:

• If the unit was in Showroom Mode during any of the 168 indexes, average temperatures will continue to be logged. No event indicator will appear with these temperatures.

• If the unit was switched OFF by pressing the POWER key during any of the 168 indexes and there was still power supplied to the control board, the average temperatures will continue to be logged. This means temperatures would be expected to rise and the SERVICE icon would be present in all indexes in which the unit was OFF.

• Temperature Log Recall Mode will end twenty (20) seconds after the last key stroke.

Temperature Log Event Indicators

The diagrams below illustrate possible event indicators that may be observed while in Temperature Log Recall Mode. (See Figures 3-53 through 3-55 and Temperature Log Index Chart on next page)

Figure 3-53. “bl” Indicates Index is “blank

” - No Temperature has Been Logged Yet

(Only possible within first 14 days of unit operation, or after new control board is installed during service)

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br 700BR

bC 700BC

27 427R bF 700BFI

2r UC-24R / UC-24RO

2C UC-24C

2b UC-24B

iLK KEZ TAKILAN ELEKTRONIK KARTLAR iÇiN KULLANILAN KART UYGULAMA PROSEDÜRÜ

Sekil 3-56. “ - - ” Çift kisa çizgi görünür = Model kodu girilmeye hazirdir.

Sekil 3-57. WARMER ya da COLDER tusuna basarak Model numarasini seçiniz.

Sekil 3-58. Aradiginiz modeli panelde görünce durunuz.

Sekil 3-59. POWER tusuna basarak onaylayip çalistiriniz.

MODEL KOD TABLOSU

KOD MODEL

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Press and hold for 15 seconds

br 700BR

bC 700BC

27 427R bF 700BFI

2r UC-24R / UC-24RO

2C UC-24C

2b UC-24B

EL YARDIMIYLA ÇALISMA SEKLi DEGiSTiRME YÖNTEMi (Daha önceden elektrik enerjisi girmis olan-kullanilmis kartlar için uygulanir)

Sekil 3-60. Ekran görüntüsü degisinceye kadar COLDER ve POWER dügmelerine basili tutunuz.

Sekil 3-61. Ekran degisinceye kadar 15 Saniye boyunca araliksiz olarak POWER dügmesini basili tutunuz.

Sekil 3-62. Ekran degisince WARMER ya da COLDER tusu ile istediginiz modeli seciniz.

Sekil 3-63. istediginiz model kodunu ekranda görünce durunuz

Sekil 3-64. POWER dügmesine basarak çalistiriniz.

MODEL KOD TABLOSU

KOD MODEL

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With unit ON, press and

hold for 5 seconds

DIS MÜDAHALE iLE DEFROST YAPTIRMA iSLEMi (YALNIZ UC-24C)

Sekil 3-65. Frezer bölümünün COLDER-WARMER ve cihazin POWER tusuna ayni anda 5 Saniye boyunca basili tutun

Page 30

Icemaker Information

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

ICEMAKER

INFORMATION

Page 31

Icemaker Information

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#7003933 - Revision B - November, 2007

MODULAR ICEMAKER

The model UC-24C utilizes a “modular icemaker.” The icemaker operation is not complex, however, an understanding of its cycle of operation is necessary in order for a serviceman to make a proper diagnosis.

Modular Icemaker Operation

When the icemaker thermostat has sensed temperatures of 17°F, the thermostat closes. At this time, the current now has a path through the thermostat to the motor. The motor is linked with the drive gear. From the module, there are copper contacts that ride on copper strips on the backside of the drive gear. (See Figure 6-1) As the drive gear rotates, these contacts from the module will make or break a circuit (track) to the copper strips to generate the icemaker cycle.

Figure 6-1. Modular Icemaker Electrical Schematic

Power

(Pink)

Contact C

(Holding Switch)

Contact A

(Water Valve)

Contact B

(Heater / Thermostat)

Contact D

(Timer)

Contact A

Contact B

Contact C

Contact D

Thermostat

Water Valve

Ta n

Green

Htr.

4400

Shut-Off

Switch

Timer

Mtr.

Neutral (White)

On (Dn)

Off (Up)

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Additional Icemaker Operation Notes

NOTES:

• There is no “ICE” key on the control panel of the UC-24C. However, you may see the ICE icon appear during Diagnostic Mode because the LCD is common with other models.

• Power to the icemaker comes direct from L-1, so it is ON 100% of the time, unless the icemaker shut-off arm is tripped to the “up / OFF” position.

• The icemaker shut-off arm must be in the “down / ON” position for the icemaker to operate.

What Happens During Ejector Blade Rotation

Figure 6-2 represents a view of the ejector blade from the front (or module side) of the icemaker. This diagram indicates what happens during the rotation of the ejector blade and will assist the Service Technician in diagnosing icemaker problems

Figure 6-2. Ejector Blade Rotation Diagram

Water Valve Energized

7.5 Seconds

140cc. or 4-3/4oz. Fill

(about 11:00 o'clock)

Thermistor Opens

in This Range of Rotation

Heater Off

6:00 o'clock (reference)

Ejector Blade Stop Position

(about 1:30 o'clock)

Start Position

Thermostat Closes

Motor On, Heater On

Ejector Blade Stalls on Ice

Motor On, Heater On

(1/2 Minute to 5 Minutes

about 4:00 o'clock)

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Under Counter (UC-24) Series

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MODULAR ICEMAKER TEST PROCEDURES

Perform the following tests if the icemaker is thought to be defective. See Figure 6-3 for icemaker test port locations. Test 1 through 5 are performed with power supplied to the icemaker, so read the “WARNING” below and the “additional Ice Production Notes” on the previous page before proceeding.

ELECTRIC SHOCK HAZARD! TESTS 1 THROUGH 5 BELOW ARE PERFORMED WITH POWER SUPPLIED TO THE ICEMAKER. CARE MUST BE TAKEN WHEN PERFORMING THESE TESTS TO AVOID SEVERE PERSONAL INJURY OR DEATH.

Voltage Tests

1. Check for power between ports “L” and “N”. Make sure test probes go into test ports 1/2”.

2. Strip 1/2” of insulation from each end of a 3” piece of insulated 14 gauge wire to create a jumper/test wire. Insert the stripped ends of this jumper/test wire into ports “T” and “H” to bypass the thermostat.

NOTE: Do not place the jumper/test wire between any other ports as this will damage the icemaker.

If the motor doesn’t run, replace the module/motor assembly.

3. Leave the jumper/test wire in until the ejector blades rotate to approximately 8:00 o’clock. The mold heater should heat up. If not, see test 5 below.

4. Remove the jumper/test wire when the ejector blades reach the 8:00 o’clock position. The water valve should energize for 7.5 seconds when the ejector blades rotate to approximately 11:00 o’clock. If not, repeat test 2 through 4 and check for power to solenoid when ejector blades rotate to approximately 11:00 o’clock. If no voltage, check electrical connections.

Continuity Tests and Thermostat Inspection

5. With icemaker removed from the unit, check the resistance of the mold heater between ports “L” and “H.” Reading should be between 62 - 82 Ohms. Replace mold/heater assembly if outside this range.

6. With the module/motor separated from the mold/heater assembly, check the resistance of the motor between ports “L” and “M.” Reading should be between 3390 - 4410 Ohms. Replace module/motor assembly if outside this range.

7. If icemaker passes tests 1 through 6, check for adequate supply of Thermal-Mastic on icemaker thermostat. If little or no Thermal-Mastic, apply Thermal-Mastic to thermostat. If adequate supply is present, replace thermostat.

8. See General Troubleshooting Guide if icemaker passes tests 1 through 7.

NOTE: Never attempt to turn the icemaker ejector blades by hand. Doing so will damage the icemaker

Figure 6-3. Icemaker Test Ports

TEST PORTS

H - T = Thermostat

L - H = Heater L - M = Motor L - N = AC Line Voltage

V - N = Valve

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WATER FILL ADJUSTMENT

The water valve should energize for approximately 7.5 seconds. This should supply 140cc. of water to the icemaker, or approximately 4.75 oz. If this is not the case, the fill amount can be adjusted with the water fill adjustment screw. (See Figure 6-4)

To increase the fill amount, turn the water fill adjustment screw counterclockwise. To decrease the fill amount, turn the water fill adjustment screw clockwise. A 360° turn will affect the fill by 40cc. A 180° turn will effect the fill by 20cc.

ICEMAKER DISASSEMBLY

Module/Motor Assembly Removal

To remove the module/motor assembly, first remove the cover and the shut-off arm. Then, extract the module/motor assembly mounting screws and pull the module from the support. (See Figure 6-5)

Mold/Heater Assembly Removal

To remove the mold/heater assembly, first remove the cover and the shut-off arm. Insert a Phillips head screwdriver into the access holes and extract the screws. Then, pull the mold/heater assembly from the support. (See Figure 6-5)

Ejector Blades and/or Ice Stripper Removal

To remove the ejector blades and/or ice stripper, first remove the cover and the shut-off arm and disconnect the mold/heater assembly from the support. (See Figure 6-5) Then, pull the ejector blades and/or ice stripper from the mold.

Icemaker Thermostat Removal

To remove the icemaker thermostat, first remove the cover and the shut-off arm and disconnect the mold/heater assembly from the support. (See Figure 6-

5) Then, use a needle-nose pliers to grasp one of the retaining clips and pull out. (See Figure 6-6)

Figure 6-4. Water Fill Adjustment

Figure 6-5. Icemaker Component Removal

Figure 6-6. Thermostat Retaining Clips

Water Fill Adjustment Screw

Modular Assembly

Mounting Screws

Mold Attachment

Screw Access Holes

(2-Phillips Head)

Shut-Off Arm

Retaining

Clips

Thermostat

Page 35

Troubleshooting Guides

Under Counter (UC-24) Series

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TROUBLESHOOTING

GUIDES

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TROUBLESHOOTING GUIDES

This section of the manual contains:

• The Error Code Table and the Error Code Troubleshooting Guide.

• The General Troubleshooting Guide, which covers all problems that a UC-24 Series unit may experience.

• The Membrane Switch/Ribbon Cable Test Procedures, used to determine if a control panel assembly is defective.

HOW TO USE THE ERROR CODE TROUBLESHOOTING GUIDE

Error Codes indicate problems registered by specific components. If error codes are registered, they will appear before temperature readings while in Diagnostic Mode.

NOTE: If Error Codes appear with a flashing “SERVICE” annunciator prior to initiating Diagnostic Mode, the unit experienced excessive compressor run condition that may or may not be associated with the Error Codes displayed.

To initiate Diagnostic Mode, press and hold either

COLDER key, then press the POWER key, then release both keys. Now, check to see if Error Codes are present, being sure to toggle through all error and temperature readings by pressing either

COLDER key or either WARMER key. (See Error Code Table Below)

If Error Codes appear during Diagnostic Mode, follow the Error Code Troubleshooting Guide on the following page. The left column of the troubleshooting guide lists the error codes. The information in the right column explains what tests to perform and/or what action to take to correct the error.

NOTE: If error codes are observed in diagnostic mode, a non-flashing SERVICE annunciator will appear on the LCD when Diagnostic Mode ends, indicating error codes are still stored. Error Codes must be cleared from the electronic control memory manually. To clear the non-flashing SERVICE annunciator and the error codes, the problem must be corrected and the unit must be ON, then:

• On a model UC-24C: Press the Freezer

WARMER and COLDER keys for fifteen (15) seconds.

• On a model UC-24B, UC-24R, or UC-24RO: Press the Refrigerator WARMER and COLDER keys for fifteen (15)

seconds.

Error Code Table

CODE INDICATION

05 Refrig. cabinet thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s 06 Refrig. evaporator thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s 07 Freezer cabinet thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s 08 Freezer evaporator thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s 20 Defrost under-heat with no voltage feedback through Gray/White wire at defrost start 21 Defrost overheat 22 No voltage feedback through Gray/White wire at defrost start 23 Defrost overheat with no voltage feedback through Gray/White wire at defrost start 24 Defrost under-heat 30 NA 40 Excessive Freezer Compressor Run 50 Excessive Refrigerator Compressor Run

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Troubleshooting Guides

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#7003933 - Revision B - November, 2007

EC TEST / ACTION

A. If “EE” for refrigerator compartment was displayed and “SERVICE” flashing, check the following:

1. Thermistor electrical connections and continuity from thermistor to J5 on control board. Reconnect / repair.

2. Resistance of thermistor - 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

B. If “EE” for refrigerator compartment was NOT

displayed, problem is intermittent thermistor error:

1. Door not closing properly. Correct door closing problem.

2. Check light switch, wiring & electrical connections. Repair wiring / connections or replace switch.

3. Check thermistor electrical connections and continuity at J5 on control board. Reconnect / repair.

4. Check resistance of thermistor - 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

C. If “EC 05” and “SERVICE” were flashing before initiating diagnostic mode, unit also experienced excessive com-

pressor run condition that may or may not be associated with the “05” Error Code. See Error Code 50 Test/Actions.

A. Initiate Diagnostic Mode. If “EE” is displayed for refrigerator evaporator thermistor, check the following:

1. Thermistor electrical connections and continuity from thermistor to J5 on control board. Reconnect / repair.

2. Resistance of thermistor - 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

B. Initiate Diagnostic Mode. If “EE” is NOT

displayed for refrigerator evaporator thermistor, problem is intermittent:

1. Door not closing properly. Correct door closing problem.

2. Check light switch, wiring & electrical connections. Repair wiring / connections or replace switch.

3. Check thermistor electrical connections and continuity at J5 on control board. Reconnect / repair.

4. Check resistance of thermistor - 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

C. If “EC 06” and “SERVICE” were flashing before initiating diagnostic mode, unit also experienced excessive com-

pressor run condition that may or may not be associated with the “06” Error Code. See Error Code 50 Test/Actions.

A. If “EE” for freezer compartment was displayed and “SERVICE” flashing, check the following:

1. Thermistor electrical connections and continuity from thermistor to J5 on control board. Reconnect / repair.

2. Resistance of thermistor - 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

B. If “EE” for freezer compartment was NOT

displayed, problem is intermittent thermistor error or caused by over-heat-

ing (above 116°F), check the following:

1. Door not closing properly. Correct door closing problem.

2. Check light switch, wiring & electrical connections. Repair wiring / connections or replace switch.

3. Check for proper mounting and location of freezer compartment thermistor. Remount correctly.

4. Check electrical connections and operation of defrost terminator - Cut-in 30°F (-1°C) /Cut-out 55°F (13°C). Reconnect / repair or replace terminator.

5. Check thermistor electrical connections and continuity at J5 on control board. Reconnect / repair.

6. Check resistance of thermistor - 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

C. If “EC 07” and “SERVICE” were flashing before initiating diagnostic mode, unit also experienced excessive com-

pressor run condition that may or may not be associated with the “07” Error Code. See Error Code 40 Test/Actions.

A. Initiate Diagnostic Mode. If “EE” is displayed for freezer evaporator thermistor, check the following:

1. Thermistor electrical connections and continuity from thermistor to J5 on control board. Reconnect / repair.

2. Resistance of thermistor - 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

B. Initiate Diagnostic Mode. If “EE” is NOT

displayed for freezer evaporator thermistor, problem is intermittent thermis-

tor error or caused by over-heating (above 116°F), check the following:

1. Door not closing properly. Correct door closing problem.

2. Check light switch, wiring & electrical connections. Repair wiring / connections or replace switch.

3. Check for proper mounting and location of freezer evaporator thermistor. Remount correctly.

4. Check electrical connections and operation of defrost terminator - Cut-in 30°F (-1°C) /Cut-out 55°F (13°C). Reconnect / repair or replace terminator.

5. Thermistor electrical connections and continuity from thermistor to J5 on control board. Reconnect / repair.

6. Resistance of thermistor - 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

C. If “EC 08” and “SERVICE” were flashing before initiating diagnostic mode, unit also experienced excessive com-

pressor run condition that may or may not be associated with the “08” Error Code. See Error Code 40 Test/Actions.

ERROR CODE TROUBLESHOOTING GUIDE

NOTE: Always clear Error Codes after repairs are complete.

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#7003933 - Revision B - November, 2007

EC TEST / ACTION

A. With cold evap. (< 10°F / -12°C), initiate Manual Defrost, then initiate Diagnostic Mode (press POWER key every

20 seconds to keep in Diagnostic Mode) and observe evap. temp. If temperature exceeds 45°F (7°C) and defrost lasts longer then 5 minutes, error code is false. Clear error code. If error code is not false:

1. Check continuity of Grey/White wire from defrost heater to J2 on control board. Reconnect / repair Grey/White wire.

2. While in defrost, check for AC power at P2 on control board. If no voltage, replace board.

3. Check continuity of Blue wire from defrost terminator to P2 on control board. Reconnect / repair Blue wire.

4. Check resistance of defrost heater (see wire diagram for proper resistance). Replace heater if defective.

5. Check electrical connections and operation of defrost terminator - Cut-in 30°F (-1°C) /Cut-out 55°F (13°C). Reconnect / repair or replace terminator.

6. Reference wiring diagram to identify components in same White wire circuit as defrost heater. Check all White wire electrical connections and continuity from defrost heater to P4 on control board.

A. With cold evap. (< 10°F / -12°C), initiate Manual Defrost, then initiate Diagnostic Mode (press POWER key every

20 seconds to keep in Diagnostic Mode) and observe evap. temp. If temperature does not

exceed 105°F (40.5°C),

error code is false. Clear error code. If error code is not false:

1. Check Blue wire connection at control board (P2). If connected to wrong pin, connect correctly.

2. Check Grey/White wire connection at control board (J2-3). if connected wrong or bad connection, reconnect / repair.

3. Check for proper mounting & location of evap. thermistor, defrost heater & terminator. Remount correctly.

4. Check for electrical short of Blue wire to another circuit. Repair Blue wire &/or electrical connections.

5. Check operation of defrost terminator - Cut-in 30°F (-1°C) /Cut-out 55°F (13°C). Replace if defective.

A. With cold evap. (< 10°F / -12°C), initiate Manual Defrost. If compressor starts 5 minutes after defrost is initiated,

check Grey/White wire and continuity from defrost heater to J2-3 on control board. Reconnect / repair Grey/White wire.

A. With cold evap. (< 10°F / -12°C), initiate Manual Defrost. If compressor starts 5 minutes after defrost is initiated,

check Grey/White wire connections and continuity from defrost heater to J2-3 on control board. Reconnect / repair

Grey/White wire. B. Check for proper mounting and location of evap. thermistor, defrost heater & terminator. Remount correctly. C. Check Blue wire connection at control board (P2). If connected to wrong pin, connect correctly. D Check for electrical short of Blue wire to another circuit. Repair Blue wire &/or electrical connections.

A. With cold evap. (< 10°F / -12°C), initiate Manual Defrost, then initiate Diagnostic Mode (press POWER key every

20 seconds to keep in Diagnostic Mode) and observe evap. temp. If temp. exceeds 45°F, error code is false. Clear

error code. If error code is not false:

1. Check Blue wire connection at control board (P2). If connected to wrong pin, connect correctly.

2. Verify proper location of Grey/White wire at control board (J2-3). if connected wrong or bad connection, reconnect / repair.

3. Check for proper mounting & location of evap. thermistor, defrost heater & terminator. Remount correctly.

ERROR CODE TROUBLESHOOTING GUIDE

NOTE: Always clear Error Codes after repairs are complete.

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Troubleshooting Guides

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#7003933 - Revision B - November, 2007

EC TEST / ACTION

A. If Error Code 07, 20, 21, 22, 23, or 24 is also displayed during Diagnostic Mode, see Test/Actions under that code. B. Check for obstructions to freezer door closing. Remove obstruction. C. Check cleanliness of condenser. Clean if needed. D. Check for obstruction to condenser fan blade or loose fan blade. Remove obstruction/Tighten Blade. E. With unit running, check for AC Power from compressor to condenser fan. Repair defective wiring or replace defec-

tive motor.

F. Check resistance of freezer compartment thermistor - 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective. G. Check evaporator fan blade position and for obstructions. Reposition if incorrect/Remove obstruction. H. With unit running and light switch depressed:

1. Check for AC Power form J3-7 to light switch. Repair wiring/Replace defective switch.

2. Check for AC Power form J3-1 to evaporator fan motor. Repair wiring/Replace defective motor.

3. Check for AC Power form P1 to compressor. Repair wiring if defective.

I. Check sealed system for leaks, restrictions or inefficient compressor.

A. If Error Code 05 is also displayed during Diagnostic Mode, see Test/Actions under that code. B. Check for obstructions to refrigerator door closing. Remove obstruction. C. Check resistance of refrigerator compartment thermistor - 30,000 to 33,000 ohms at 32°F (0°C). Replace if defec-

tive.

D. Check refrigerator compartment fan blade position and for obstructions. Reposition if incorrect/Remove obstruction. E. With unit running and light switch depressed:

1. Check for AC Power form J3-5 to evaporator fan motor. Repair wiring/Replace defective motor.

F. Check air baffle control operation. Repair wiring/Replace if defective. G. Check sealed system for leaks, restrictions or inefficient compressor.

ERROR CODE TROUBLESHOOTING GUIDE

NOTE: Always clear Error Codes after repairs are complete.

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Troubleshooting Guides

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#7003933 - Revision B - November, 2007

HOW TO USE THE GENERAL TROUBLESHOOTING GUIDE

• The table on page 8-7 indicate how the General Trouble Shooting Guide is arranged.

• Identify the description of the problem that the unit is experiencing from the table.

• To the left of the problem description is a letter.

• Locate that letter in the left column of the General Troubleshooting Guide.

• The center column will identify the possible causes for the problem.

• The information in the right column explains the tests to perform and/or action to take to correct the problem.

• If the unit is experiencing temperature problems, refer to the instructions below before beginning troubleshooting.

For Temperature Problems

1. Begin troubleshooting by observing compartment set points.

2. If set-points are normal, initiate Diagnostic Mode by pressing and holding either

COLDER key, then press

POWER key, then release both keys.

NOTE: Diagnostic Mode will end twenty (20) seconds after last key stroke.

3. When Diagnostic Mode is initiated, check to see if “Error Codes” are present, being sure to toggle through all error codes and temperature readings by pressing either

COLDER key, or either WARMER key. (See

Thermistor Location Code Tables below.)

4. If Error Codes are present, refer to Error Code Troubleshooting Guide, which starts on page 8-2.

5. If no Error Codes are observed, see General Troubleshooting Guide Table of Contents on following page.

NOTE: If compartment and/or evaporator temperature history is needed to help diagnose problem, initiate Temperature Log Recall Mode. Begin with unit ON and in Diagnostic Mode. While in Diagnostic Mode, toggle

through readings until desired thermistor temperature is displayed on LCD. Now, press POWER key then either WARMER key simultaneously. Toggle through indexes by pressing WARMER or COLDER key.

Models UC-24R, UC-24RO

THERMISTOR LOCATION CODE

Refrigerator Compartment r

Evaporator E

Model UC-24C

THERMISTOR LOCATION CODE

Freezer Compartment F

Refrigerator Compartment r

Evaporator E

Model UC-24B

THERMISTOR LOCATION CODE

Beverage Compartment r

Evaporator E

THERMISTOR LOCATION CODE TABLES

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#7003933 - Revision B - November, 2007

GENERAL TROUBLESHOOTING GUIDE TABLE OF CONTENTS

Page #

A. “EE” Displayed in place of Freezer Temperature with “SERVICE” Flashing .................................................... 8-8

B. “EE” Displayed in place of Refrigerator Temperature with “SERVICE” Flashing .............................................. 8-8

C. Warm or Normal Temperatures Displayed with “SERVICE” Alone

Flashing .................................................... 8-8

D. Warm or Normal Temperatures Displayed with non-flashing

“SERVICE” Displayed ....................................... 8-8

E. Erratic Temperatures with or without

“SERVICE” Flashing .............................................................................. 8-8

F. Warm Refrigerator Temperatures, “SERVICE” not displayed or Flashing

...................................................... 8-8

G. Refrigerator Temperatures Too Cold with or without

“SERVICE” Flashing (UC-24C ONLY) ........................... 8-8

H. Warm Freezer Temperatures, “SERVICE” not displayed or Flashing

............................................................. 8-10

I. Product Temperature 10° or More Colder than Displayed Temperature ....................................................... 8-12

J. 1. “Extremely” Cold Temperatures Displayed .............................................................................................. 8-12

• 1° to 7° in Refrigerator

• -21° to -15° in Freezer

2. If outside US - “Extremely” Warm Temperatures Displayed

• 34° to 45° in Refrigerator

• -5° to 5° in Freezer

K. No Ice ............................................................................................................................................................. 8-12

L. Icemaker produces Too much ice ................................................................................................................. 8-13

M. Icemaker Produces Hollow Cubes ................................................................................................................. 8-13

N. Icemaker Produces Small Cubes ................................................................................................................... 8-13

O. Water or Clump of Ice in Ice Bucket .............................................................................................................. 8-13

P. No LCD ......................................................................................................................................................... 8-13

Q. No Lights ....................................................................................................................................................... 8-14

R. Lights Stay ON when Door is Closed ............................................................................................................. 8-14

S. Door Not Able to Close Completely ............................................................................................................... 8-14

T. Door Uneven ................................................................................................................................................... 8-14

SEALED SYSTEM DIAGNOSTICS TABLES ................................................................................................. 8-15

• Normal Operating Pressures..................................................................................................................... 8-15

• Pressure Indications................................................................................................................................... 8-15

• Temperature / Pressure Correlation........................................................................................................... 8-16

MEMBRANE SWITCH / RIBBON CABLE TEST ............................................................................................ 8-17

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Troubleshooting Guides

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#7003933 - Revision B - November, 2007

PROBLEM POSSIBLE CAUSE TEST / ACTION

A. “EE” Displayed in place of

Freezer Temperature with “SERVICE” Flashing

B. “EE” Displayed in place of

Refrigerator Temperature with “SERVICE” Flashing

C. Warm or Normal

Temperatures Displayed with “SERVICE” Alone Flashing

D. Warm or Normal

Temperatures Displayed with non-flashing “SERVICE” Displayed

E. Erratic Temperatures with or

without “SERVICE” Flashing

F. Warm Refrigerator

Temperatures, “SERVICE” not

displayed or Flashing

(Continued)

Freezer Compartment Thermistor Disconnected, Shorted, or misread

Refrigerator Compartment Thermistor Disconnected, Shorted, or misread

Excessive Compressor or Evaporator Fan Run

Refrigerator Evaporator Thermistor Disconnected, Shorted, or misread

Error Codes Observed in Diagnostic Mode, but not Cleared from Memory

Control Board Configured for Wrong Model

No Power to Unit

Unit Switched OFF

Unit in Show Room Mode

Control Set Too High

Warm Food Load

High Room Ambient

Door Ajar

a. Food Product Obstruction b. Door Closer Defective

Faulty Light Switch

Check freezer compartment thermistor electrical connections from thermistor to control board. Reconnect / repair connections. Check resistance of freezer compartment thermistor for 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

Check refrigerator compartment thermistor electrical connections from thermistor to control board. Reconnect / repair connections. Check resistance of refrigerator compartment thermistor for 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

Initiate Diagnostic Mode and see Error Code Troubleshooting Guide

Check evaporator thermistor electrical connections from thermistor to control board. Reconnect / repair connections. Check resistance of evaporator thermistor for 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

Enter diagnostic mode to observe error codes. See Error Code Troubleshooting Guide. Verify unit was repaired for error codes displayed. Press appropriate WARMER and COLDER keys for 15 seconds to clear error codes.

Initiate Manual Model Configuration Mode and reconfigure to correct model.

Check power to unit, plug unit in or switch supply circuit breaker ON.

Check for “OFF” displayed at LCD. If off, press POWER key.

Switch unit to OFF, then press and hold WARMER & COLDER keys, and press POWER key.

Check set-point. If high, adjust.

Check contents of refrigerator for warm food load. Instruct customer.

Instruct customer unit performs best between 60°F(16°C) and 90°F(32°C).

a. Move obstruction. b. Replace door closer.

Check operation of light switch, lights off when switch is depressed. Replace switch if defective.

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#7003933 - Revision B - November, 2007

PROBLEM POSSIBLE CAUSE TEST / ACTION

(Continued)

F. Warm Refrigerator

Temperatures, “SERVICE” not

displayed or Flashing

G. Refrigerator Temperatures

Too Cold with or without “SERVICE” Flashing (Model UC-24C ONLY)

Evaporator Fan Fault

a. Fan blade obstructed or out of position b. Evaporator fan motor disconnected

c. Power to Fan Fault, or Fan Motor

Defective

(NOTE: Compressor must be running)

Compartment Thermistor Misread

Air Baffle Control Fault

(Model UC-24C ONLY)

a. Baffle Control Stuck

b. Baffle Control Disconnected, Defective,

or not Receiving Signal from Control Board.

Evaporator Heavily Frosted

a. Door ajar b. Evaporator fan fault c. Compartment thermistor misread

Power to Compressor Fault

Sealed System Fault

• Sealed System Leak

• Sealed System Restriction

• Inefficient Compressor

See Air Baffle Control Fault above

(Under Problem F)

a. Move obstruction or reposition blade. b. Check electrical connections & continuity

from control board to motor. Reconnect / repair bad connections.

c. With light switch depressed, check for AC

Voltage from control board to fan motor. Replace control board if defective, or Replace motor if defective.

Check resistance of refrigerator compartment thermistor for 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

a. Manually open / close air baffle control. If

movement is not smooth, replace baffle control.

b. With light switch depressed, initiate Manual

Compartment Activation Mode for refrigerator compartment and observe baffle operation. If baffle does not open within 3 minutes:

1. Check electrical connections from baffle control to control board. Reconnect / repair bad connections.

2. If electrical connections and wiring are good, and baffle moves freely, replace control board.

a. See Door Ajar above. b. See Evaporator Fan Fault above. c. See Thermistor Misread above

Check for AC Voltage at control board. Replace control board if defective.

See Sealed System Troubleshooting Guide

See Air Baffle Control Fault above (Under Problem F)

Low Voltage Circuit. Do NOT apply Line Voltage

Page 44

Troubleshooting Guides

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

PROBLEM POSSIBLE CAUSE TEST / ACTION

H. Warm Freezer Temperatures,

“SERVICE” not

displayed or

Flashing

No Power to Unit

Unit Switched OFF

Unit in Show Room Mode

Control Set Too High

Warm Food Load

High Room Ambient

Door Ajar

a. Food Product Obstruction b. Door Closer Defective

Condenser Air Flow

a. Dirty condenser b. Condenser fan blade obstructed, loose,

or defective

c. Condenser fan motor disconnected

d. Condenser fan motor defective

Faulty Light Switch

Evaporator Fan Fault

a. Fan blade obstructed or out of position b. Evaporator fan motor disconnected

c. Power to Fan Fault, or Fan Motor

Defective

(NOTE: Compressor must be running)

Compartment Thermistor Misread

Check power to unit, plug unit in or switch supply circuit breaker ON.

Check for “OFF” displayed at LCD. If off, press POWER key.

Press POWER key to OFF, then press and hold WARMER& COLDER keys, and press POWER key.

Check set-point. If high, adjust.

Check contents of freezer for warm food load. Instruct customer.

Instruct customer unit performs best between 60°F(16°C) and 90°F(32°C).

a. Move obstruction. b. Replace door closer.

a. Clean condenser. b. Remove obstruction, or tighten blade, or

replace if defective.

c. Check continuity from motor to compressor.

Reconnect / repair wiring or connections.

d. Check for AC Voltage to motor, replace if

defective.

Check operation of light switch, lights off when switch is depressed. Replace switch if defective.

a. Move obstruction or reposition blade. b. Check electrical connections & continuity

from control board to motor. Reconnect / repair bad connections.

c. With light switch depressed, check for AC

Voltage from control board to fan motor. Replace control board if defective, or Replace motor if defective.

Check resistance of freezer compartment thermistor for 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

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Troubleshooting Guides

Under Counter (UC-24) Series

8-11

#7003933 - Revision B - November, 2007

PROBLEM POSSIBLE CAUSE TEST / ACTION

(Continued)

H. Warm Freezer Temperatures,

“SERVICE” not

displayed or

Flashing

I. Product Temperature 10° or

More Colder than Displayed Temperature

J. 1. “Extremely” Cold

Temperatures Displayed

• 1° to 7° in Refrigerator

• -21° to -15° in Freezer

2. If outside US “Extremely” Warm Temperatures Displayed

• 34° to 45° in Refrigerator

• -5° to 5° in Freezer

Evaporator Heavily Frosted

a. Door ajar b. Evaporator fan fault c. Compartment thermistor misread d. Defrost heater disconnected or faulty

e. Defrost terminator disconnected or

faulty.

f. Defrost sense line disconnected.

g. No power from control board to defrost

circuit

Power to Compressor Fault

Sealed System Fault

• Sealed System Leak

• Sealed System Restriction

• Inefficient Compressor

Compartment Thermistor Misread

1. Control Set to Display Celsius

2. If Outside US - Control Set to Display Fahrenheit

a. See Door Ajar above. b. See Evaporator Fan Fault above. c. See Thermistor Misread above d. Check electrical connections. Reconnect /

repair bad connections. Check resistance of heater, 30-38 Ohms, replace if defective.

e. Check electrical connections, Reconnect /

repair connections or replace bad terminator.

f. Manually initiate defrost - press ICE key for

10 seconds. If defrost lasts exactly 5 minutes, check all connections of gray/white wire from terminator to control board. Reconnect / repair bad connections.

g. Manually initiate defrost - Press ICE key for

10 seconds. Check for AC Voltage at control board. Replace control board if defective.

Check for AC Voltage at control board. Replace control board if defective.

See Sealed System Troubleshooting Guide

Check resistance of compartment thermistor for 30,000 to 33,000 ohms at 32°F (0°C). Replace if defective.

1. Change temperature units of measure to Fahrenheit.

2. If Outside US - Change temperature units of measure to Celsius.

Page 46

Troubleshooting Guides

Under Counter (UC-24) Series

8-12

#7003933 - Revision B - November, 2007

PROBLEM POSSIBLE CAUSE TEST / ACTION

K. No Ice No Water Supply to Unit

Unit Has Not Run Long Enough

Warm Freezer Temperatures

(NOTE: Freezer must be 17°F (-8°C) or colder for icemaker to function)

Shut-off Arm Stuck in Up/Off Position

Disconnected or Defective Water Valve

No Power to Icemaker

Frozen Fill Tube - Water Supply Problem

Icemaker System Fault

a. Disconnected or damaged electrical

connections at icemaker or water valve.

b. Defective icemaker

c. Defective icemaker

d. Disconnected or damaged electrical

connections at icemaker

Connect/turn on water supply.

Freezer must be 17°F (-8°C) for icemaker to operate, approximately 24 hours after unit installation. Instruct customer.

See PROBLEM A, C, D, E, & G earlier in Troubleshooting Guide.

Check shut-off arm, if stuck in up/OFF position, correct problem.

Check electrical connections and water connections at water valve, Reconnect / repair connections. Check resistance of water valve, 160 ohms. Replace if defective.

Check for power to icemaker. If no power repair / reconnect wiring.

Check water supply pressure for “constant” 20-100 PSI. If not, instruct customer.

Manually start icemaker with jumper between ports “T” & “H”. Watch cycle of icemaker and see #1, #2 & #3 below.

1. If icemaker motor starts and finishes cycle:

a. Check for 115V at valve during fill mode. If

no 115V, inspect connections at icemaker and valve. Repair or replace connection.

b. Check for 115V from icemaker during fill

mode. If no power, replace icemaker.

2. If icemaker motor starts but does not finish cycle:

c. Replace icemaker.

3. If icemaker motor does NOT start:

d. Check for 115V to icemaker. If no power,

repair electrical connection.

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Troubleshooting Guides

Under Counter (UC-24) Series

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#7003933 - Revision B - November, 2007

PROBLEM POSSIBLE CAUSE TEST / ACTION

L. Icemaker produces Too

much ice

M. Icemaker Produces Hollow

Cubes

N. Icemaker Produces Small

cubes

O. Water or Clump of Ice in Ice

Bucket

P. No LCD

Ice Level Arm/Linkage Bent or Broken

Icemaker Faulty

Freezer Too Cold, Cycles Icemaker Too Soon

Not Enough Thermal-Mastic on Icemaker Thermostat

Icemaker Thermostat Fault

Water Supply Problem

Icemaker Not Level

Low Fill Adjustment on Icemaker

Icemaker Not Level

High Fill Adjustment on Icemaker

Water Valve Energized Too Long

Intermittent Warm Freezer Temperatures

Unit in Sabbath Mode

Display Wire Harness Disconnected or Faulty

Control Panel Assembly Defective (OR) No Signal Read at Control Board

Inspect ice level / shut-off arm. Replace defective parts.

With ice level arm in UP/OFF position, manually start icemaker with jumper between ports “T” & “H”. If icemaker motor starts with arm in the UP/OFF position, replace icemaker.

See PROBLEM “H” earlier in Troubleshooting Guide.

Inspect icemaker thermostat, apply more Thermal-Mastic to thermostat.

Replace Thermostat.

Check water supply pressure; must be constant 20-100 PSI. If not, instruct customer.

Check level of icemaker, adjust if needed

Check for 100-110 cc. fill (3.5-3.75 oz.). If low, increase fill by turning adjusting screw counterclockwise.

Check level of icemaker, level if needed.

Check for 100-110 cc. fill (3.5-3.75 oz.). Turn adjusting screw clockwise to decrease.

• Check icemaker for jammed ice cube, clear jam if present.

• Check icemaker levelness; level if needed.

• Check position of fill cup. Reposition if in ice path.

• Check water supply pressure; must be constant 20-100 PSI. If not, instruct customer.

• Check water valve operation, opens when AC Voltage is applied, closes completely when AC Voltage is removed. Water valve Ohms = 160. Replace if defective.

See PROBLEM A, C, D, E, & H earlier in Troubleshooting Guide.

Exit Sabbath Mode.

Check display wire harness and connections. Reconnect, repair, replace bad wiring.

See Membrane Switch/Ribbon Cable Test Procedures. If membrane switch fails any test, replace entire control panel assembly. If switch passes all tests, replace control board.

Page 48

Troubleshooting Guides

Under Counter (UC-24) Series

8-14

#7003933 - Revision B - November, 2007

PROBLEM POSSIBLE CAUSE TEST / ACTION

Q. No Lights

R. Lights Stay ON when Door is

Closed

S. Door Not Able to Close

Completely

T. Door Uneven

No power to unit

Unit switched OFF

Unit in Sabbath Mode

Defective or loose light bulb(s)

Light Switch Disconnected or Defective

Lighting System Wiring Disconnected or Defective

No Power From Control Board

(NOTE: See Unit in Sabbath Mode above.)

Accent Lights Switched ON (Model UC-24B ONLY)

Door Ajar

a. Food product obstruction b. Door Closer Defective

Faulty Light Switch

Food Product Obstruction

Door Closer Defective

Unit Not Level

Check power to unit, plug unit in or switch supply circuit breaker ON.

Switch unit ON, press POWER key.

Exit Sabbath Mode.

Install a known good light bulb.

Check wire connections at light switch. Reconnect/repair. Check for AC Voltage to and from light switch. Replace switch if defective.

Check continuity from light sockets to switch. Reconnect/repair or replace defective components.

Check for AC Voltage from control board. Replace board if defective. (NOTE: See Unit in Sabbath Mode above.)

Switch Accent Lights OFF

a. Move obstruction. b. Replace door closer.

Check operation of light switch, lights off when switch is depressed. Replace switch if defective.

Move obstruction.

Replace door closer.

Check levelness of unit. If un-level, turn leveling legs counterclockwise to raise unit or clockwise to lower it.

Page 49

Troubleshooting Guides

Under Counter (UC-24) Series

8-15

#7003933 - Revision B - November, 2007

UC-24C

5” Vac - 1 psi to 6 - 12 psi 75 psi to 120 psi

UC-24R / UC-24RO

0 - 12 psi to 30 - 42 psi 75 psi to 110 psi

SEALED SYSTEM DIAGNOSTICS TABLES

NORMAL OPERATING PRESSURES TABLE NOTES:

• Only enter the sealed system to check pressures if the Error Code Troubleshooting Guide and General Troubleshooting Guide could not pinpoint the cause of the temperature problem.

• Always use solder-on process valves when entering the sealed system. Do NOT use bolt-on process valves as they are prone to leak.

• Whenever servicing the sealed system, the high-side filter-drier MUST be replaced.

• Pressures listed below are not indicative of initial pull down, but rather of a steadily running and properly functioning appliance.

• Pressures listed are for reference only, as actual pressure readings may vary because of one or more of the following reasons:

1. Ambient temperatures (Pressures are based on a 70°F (21°C) Ambient).

2. Temperature set-points (Pressures listed below are based on set-points of 0°F (-18°C) in freezers and 38°F

(3°C) in refrigerators)

3. Food load quantity and temperature.

4. Condenser cleanliness.

5. Whether or not one or both refrigeration systems are operating.

6. Gauge calibration.

NORMAL OPERATING PRESSURES

Model Normal Low-Side Pressures Normal High-Side Pressures

UC-24B

0 - 12 psi to 30 - 42 psi 75 psi to 110 psi

PRESSURE INDICATIONS

If low-side pressure is

NORMAL

LOW

HIGH

& high-side pressure is

NORMAL

LOW

HIGH

LOW

HIGH

possible problem is

MECHANICAL

(see General Troubleshooting Guide)

LEAK

RESTRICTION

INEFFICIENT COMPRESSOR

OVER CHARGE

Page 50

Troubleshooting Guides

Under Counter (UC-24) Series

8-16

#7003933 - Revision B - November, 2007

EVAPORATOR TEMPERATURE / SEALED SYSTEM LOW-SIDE PRESSURE CORRELATION

Pressure

10” Vac

7” Vac 4” Vac 0” Vac

2 Psi 4 Psi 7 Psi

9 Psi 12 Psi 15 Psi 18 Psi 22 Psi 26 Psi 30 Psi 35 Psi 40 Psi 45 Psi 51 Psi 57 Psi 64 Psi 71 Psi 78 Psi

NOTE: The temperature/pressure table at right is for reference only. A unit's temperature/pressure correlation may differ from those listed due to: variations in evaporator thermistor location, set-points, where the sealed system is in the refrigeration cycle, ambient temperature, etc. If a unit is experiencing temperature problems, it is recommended that you reference the General Troubleshooting Guide before accessing the sealed system. After all mechanical and electrical components have been ruled out, sealed system pressures can be checked by applying solder-on process valves and referencing the preceding page. Do NOT

use bolt-on process valves as they are prone to leak. This table should only be used as a last quick check before entering the sealed system.

Temperature

-30°F (-34°C)

-25°F (-32°C)

-20°F (-29°C)

-15°F (-26°C)

-10°F (-23°C)

-5°F (-21°C) 0°F (-18°C) 5°F (-15°C)

10°F (-12°C)

15°F (-9°C) 20°F (-7°C) 25°F (-4°C) 30°F (-1°C)

35°F (2°C) 40°F (4°C)

45°F (7°C) 50°F (10°C) 55°F (13°C) 60°F (16°C) 65°F (18°C) 70°F (21°C) 75°F (24°C)

Page 51

Troubleshooting Guides

Under Counter (UC-24) Series

8-17

#7003933 - Revision B - November, 2007

Ribbon Cable Terminal Housing

NOTE: See “How To Identify Pin 1”, above.

Control Panel Assembly

Figure 9-2. UC-24C Control Panel Assembly

FREEZER

COLDER

KEY

REFRIG

COLDER

KEY

REFRIG

WARMER

KEY

FREEZER

WARMER

KEY

POWER

KEY

MODEL

NA 1 - 34 - 5NA3 - 4UC-24B

1 - 5 1 - 34 - 51 - 23 - 4UC-24C

NA 1 - 34 - 5NA3 - 4UC-24R

NA 1 - 34 - 5NA3 - 4UC-24RO

CONTROL PANEL MEMBRANE SWITCH / RIBBON CABLE TEST

If integrity of control panel assembly is suspect, perform continuity tests at membrane switch ribbon cable terminal housing. Begin by removing control panel assembly from unit and place it on solid surface, then disconnecting ribbon cable from control panel PC board.

Pin 1 Identification Procedure

The ribbon cable wires are exposed at the back-side of the terminal housing. Place ohm meter leads between 1st and 2nd pin from each end of the housing while pushing the Freezer

WARMER key of a Model UC-24C, or the Refrigerator WARMER key of a Model UC-24B, UC-24R, or UC-24RO. When continuity is observed, pin 1 is at that end of the terminal housing.

Continuity Test Procedure

1. Without pressing any of the keys on the membrane switch, check for continuity across all pin combinations. With

no keys pressed, there should be no continuity between any two pins.

2. Identify model number being serviced in left column of table below.

3. Press key listed at top of table.

4. Corresponding numbers to right of model number and below key being pressed are the pin numbers on terminal

housing that should have continuity.

NOTE: If any continuity tests show failure, replace entire control panel assembly.

Page 52

Technical Data

Under Counter (UC-24) Series

9-1

#7003933 - Revision B - November, 2007

TECHNICAL DATA

Page 53

Technical Data

Under Counter (UC-24) Series

9-2

#7003933 - Revision B - November, 2007

Model UC-24B

REFRIGERATOR

CHARGE (R-134a Refrigerant)

NOTE: Always check serial tag for exact charge

NORMAL OPERATING PRESSURES

Low Side

High Side

COMPRESSOR

NOTE: Always check parts price list for possible substitutions.

Service Part No.

Manufacturer

Manufacturer Model Number

Original/Service Compressor Amps

Original/Service Compressor BTU/H

DEFROST METHOD

THERMISTORS

Resistance/Ohms at 32°F / 0°C

3.75 oz. (0.11 Kg)

0 - 12 psi to 30 - 42 psi

75 psi to 110 psi

7002177

Embraco

EMU45HSC

~1.5 / ~1.5

450 / 450

“Fan Assisted Off-Cycle Defrost”

Evap > 38°F (3°C) before

Compressor ON.

30000 - 33000

Page 54

Technical Data

Under Counter (UC-24) Series

9-3

#7003933 - Revision B - November, 2007

Model UC-24C

FREEZER

CHARGE (R-134a Refrigerant)

NOTE: Always check serial tag for exact charge

NORMAL OPERATING PRESSURES

Low Side

High Side

COMPRESSOR

NOTE: Always check parts price list for possible substitutions.

Service Part No.

Manufacturer

Manufacturer Model Number

Original/Service Compressor Amps

Original/Service Compressor BTU/H

DEFROST METHOD

DEFROST TERMINATOR

Cut-In Temp.

Cut-Out Temp.

DEFROST HEATER

Watts Amps

Resistance/Ohms

WATER VALVE

Watts Amps

Resistance/Ohms (Inductive)

THERMISTORS

Resistance/Ohms at 32°F / 0°C

4.5 oz. (0.13 Kg)

5” Vac - 1 psi to 6 - 12 psi

75 psi to 120 psi

7002177

Embraco

EMU45HSC

~1.5 / ~1.5

450 / 450

“Adaptive Defrost”

Defrost intervals and duration vary by unit use. 5 minute compressor delay after each defrost.

30°F (-1°C)

55°F ( 13°C)

240

1.9 - 2.3 50 - 61

0.42 160

30000 - 33000

Never replace the defrost terminator with another having a cut-out limit above 55°F (13°C), as this will damage the appliance.

Page 55

Technical Data

Under Counter (UC-24) Series

9-4

#7003933 - Revision B - November, 2007

Model UC-24R / UC-24RO

REFRIGERATOR

CHARGE (R-134a Refrigerant)

NOTE: Always check serial tag for exact charge

NORMAL OPERATING PRESSURES

Low Side

High Side

COMPRESSOR

NOTE: Always check parts price list for possible substitutions.

Service Part No.

Manufacturer

Manufacturer Model Number

Original/Service Compressor Amps

Original/Service Compressor BTU/H

DEFROST METHOD

THERMISTORS

Resistance/Ohms at 32°F / 0°C

3.75 oz. (0.11 Kg)

0 - 12 psi to 30 - 42 psi

75 psi to 110 psi

7002177

Embraco

EMU45HSC

~1.5 / ~1.5

450 / 450

“Fan Assisted Off-Cycle Defrost”

Evap > 38°F (3°C) before

Compressor ON.

30000 - 33000

Page 56

Wire Diagrams & Schematics

Under Counter (UC-24) Series

10-1

#7003933 - Revision B - November, 2007

WIRING DIAGRAMS

AND SCHEMATICS

Page 57

J5-5,6

J6-2

SERIAL DATE TRANSMIT

SENSES EVAPORATOR TEMPERATURE

NOT USED

REF DOOR LIGHT SENSE

NOT USED

NEUTRAL

DEFROST HEATER

FREEZER COMPARTMENT

DEFROST SENSOR

DISPLAY WIRING

BAFFLE CLOSE

GRAY/WHITE

EVAP

DISPLAY

LIGHTS

FAN 1

COMPRESSOR

LOW VOLTAGE THERMISTOR CIRCUITS

120 VOLT CIRCUITS

J3-3

J3-1

J3-2

J3-6

J3-5

J3-4

J2-1

J3-7

J5-1,2

J2-4

J2-3

J2-2

J4-5

J5-3,4

J5-7

J6-1

J5-8

J4-2

J4-1

J6-3

J4-4

J4-3

J4-6

12VDC POWER SUPPLY FOR DISPLAY BOARD

GROUND FOR DISPLAY BOARD POWER SUPPLY

SERIAL DATA RECEIVE

SENSES EVAPORATOR TEMPERATURE

SENSES IF LOWER DOOR OPEN

POWERS COMPRESSOR AND CONDENSER FAN

POWERS EVAPORATOR FAN

POWER INTO BOARD

NEUTRAL INTO BOARD

NOT USED

EVAPORATOR FAN

COMPRESSOR

POWER IN

LIGHTS

NOT USED

POWERS LIGHTS

REF COMPARTMENT

DISPLAY WIRING

EVAPORATOR

DISPLAY WIRING

EVAPORATOR

BAFFLE OPEN

BAFFLE NEUTRAL

WHITE

PURPLE

BLACK

RED

YELLOW

ORANGE

BLUE/RED

WHITE

YELLOW

ORANGE/RED

RED

SENSES REF CABINET TEMPERATURE

CAB

BLUE/BLACK

BAFFLE NEUTRAL

YELLOW/RED

PULSED TO CLOSE NEUTRAL

YELLOW/BLACK

YELLOW/WHITE

PULSED TO OPEN NEUTRAL

DEFROST

ICE

FAN 1

R DOOR

DEF

ICE

POWERS DEFROST CIRCUIT

BLUE

SENSES WHEN DEFROST HEATER SHUTS OFF

CAB SENSES FREEZER CABINET TEMP

BLUE/WHITE

CIRCUIT

TERMINAL

MAIN CONTROL BOARD SUMMARY

DESCRIPTION

FUNCTION COLOR

-This wiring information is provided for use by qualified service personnel only.

-Disconnect appliance from electrical supply before beginning service.

-Be sure all grounding devices are connected when service is complete.

-Failure to observe the above warnings may result in severe electrical shock.

ORANGE YELLOW

PIN 1

2 3 4

RED WHITE

ORANGE

YELLOW

ORANGE

1 2

WHITE

PLAIN

GREEN

RIBBED

1 BLACK

2 WHITE

1 PURPLE

2 WHITE

3 GRN/YL STP

2 BROWN

1 BLUE

WHITE

PURPLE

WHITE

GREEN

BLACK

WHITE

GREEN W/YELLOW STRIPE

PURPLE

TAN

WHITE

GREEN/YELLOW STRIPE

YELLOW/RED STRIPE YELLOW/BLACK STRIPE YELLOW/WHITE STRIPE

MAIN BOARD

BLACK

PURPLE

YELLOW

RED

WHITE

YELLOW/BLACK

ORANGE

RED

WHITE

YELLOW

ORANGE

ORANGE/BLACK STRIPE

RED

WHITE 11

YELLOW 4

BLUE/BLACK STRIPE

ORANGE

RED

ORANGE

BLUE/RED STRIPE

ORNG/RED STRIPE

ORANGE

14110

WHITE

RED

BLACK

ORANGE

YELLOW 8

YELLOW/WHITE STRIPE YELLOW/BLACK STRIPE YELLOW/RED STRIPE

PINK

WHITE

TAN

GRN/YLW

BLUE

GRAY/WHITE 13

GRAY/WHITE

BLUE/WHITE STRIPE

YELLOW/WHITE 7

YELLOW/RED 5

WHITE

RED

WHITE

RED

SENSOR

UPPER

REF LIGHT

MOTOR

REF FAN

(REF CAB)

SENSOR

(EVAP)

THERMAL

FUSE

ICEMAKER

DEFROST HEATER

BLACK

GRAY/WHITE STRIPE

BLUE

DEFROST TERMINATOR

GRAY

BLUE

(FZ CAB)

SENSOR

JACKET CABLE (MARKED WITH GREEN STRIPE)

JACKET CABLE (MARKED WITH 2 GREEN STRIPES)

JACKET CABLE (MARKED WITH 2 BLUE STRIPES)

MFG TEST TERMINALS

COMPRESSOR

CORD

SUPPLY

POWER

CONDENSER FAN MOTOR

PIN 1

MAIN CONTROL BOARD DETAIL

PIN 1

SWITCH LIGHT

DISPLAY BOARD

REF AIR DUCT

BAFFLE

SOLENOID

ICEMAKER

(OPTIONAL)

WIRING DIAGRAM MODEL UC-24C

P/N 7002956 REV A

PURPLE

Wire Diagrams & Schematics

Under Counter (UC-24) Series

10-2

#7003933 - Revision B - November, 2007

Page 58

Wire Diagrams & Schematics

Under Counter (UC-24) Series

10-3

#7003933 - Revision B - November, 2007

P/N 7002956 REV A

WIRING SCHEMATIC MODEL UC-24C

-This wiring information is provided for use by qualified service personnel only.

-Disconnect appliance from electrical supply before beginning service.

-Be sure all grounding devices are connected when service is complete.

-Failure to observe the above warnings may result in severe electrical shock.

LOW VOLTAGE SCHEMATIC

PIN 1

THERMISTOR CABINET/FREEZER

HIGH VOLTAGE SCHEMATIC

ORANGE

MEMBRANE KEYPAD

DISPLAY

DISPLAY BOARD

THERMISTOR CABINET/REF

GRAY/WHITE

REF AIR DUCT BAFFLE

THERMISTOR

EVAPORATOR

115 VOLTS 60 CYCLES

NEUTRAL

PIN 1

YELLOW W/WHITE STRIPE

YELLOW W/BLACK STRIPE

YELLOW W/RED STRIPE

PIN 1

MAIN BOARD

ORANGE

YELLOW

BLUE W/RED STRIPE

ORANGE W/RED STRIPE

BLUE W/WHITE STRIPE BLUE W/WHITE STRIPE

BLUE W/BLACK STRIPE BLUE W/BLACK STRIPE

WHITE

RED

PIN 1

WHITE

PIN 1

MAIN BOARD

PIN 1

ORANGE

PIN 1

WHITE

BLACK

PURPLE

BLUE

YELLOW

ORANGE

REF LIGHT SWITCH

BLACK

RED

THERMAL

FUSE

GRAY/WHITE

ICEMAKER

OVERLOAD

PROTECTOR

CONDENSER FAN

DEFROST HEATER

R55 OHMS

REF (TOP) LIGHT

WHITE

TAN

COMPRESSOR

REF FAN MOTOR

ICEMAKER

VALV E

R160 OHMS

RUNNING

CAPACITOR

COMPRESSOR STARTING RELAY

WHITE

(WHEN USED)

WHITE

Page 59

WHITE

PURPLE

BLACK

RED

YELLOW

ORANGE

BLUE/RED

WHITE

YELLOW

ORANGE/RED

RED

BLUE/BLACK

12VDC POWER SUPPLY FOR DISPLAY BOARD

GROUND FOR DISPLAY BOARD POWER SUPPLY

SERIAL DATE TRANSMIT

SERIAL DATA RECEIVE

SENSES EVAPORATOR TEMPERATURE

SENSES IF LOWER DOOR OPEN

POWERS COMPRESSOR AND CONDENSER FAN

SENSES EVAPORATOR TEMPERATURE

POWERS EVAPORATOR FAN

POWER INTO BOARD

NEUTRAL INTO BOARD

POWERS LIGHTS

SENSES REFER CABINET TEMPERATURE

NOT USED

REF DOOR LIGHT SENSE

NOT USED

NEUTRAL

NOT USED

EVAPORATOR FAN

NOT USED

COMPRESSOR

POWER IN

LIGHTS

NOT USED

REFRIGERATOR

COMPARTMENT

DISPLAY WIRING

EVAPORATOR

DISPLAY WIRING

EVAPORATOR

NOT USED

EVAP

DISPLAY

LIGHTS

FAN 1

COMPRESSOR

CAB

DEFROST

ICE

FAN 1

R DOOR

DEF

ICE

LOW VOLTAGE THERMISTOR CIRCUITS

J5-5,6

J3-3

P3P4P2

J3-1

J3-2

J3-6

J3-5

J3-4

J2-1

J3-7

J5-1,2

J2-4

J2-3

J2-2

J4-5

J5-3,4

J5-7

J6-2

J6-1

J5-8

J4-2

J4-1

J6-3

J4-4

J4-3

J4-6

120 VOLT CIRCUITS

CIRCUITTERMINAL

MAIN CONTROL BOARD SUMMARY

DESCRIPTION FUNCTION COLOR

-This wiring information is provided for use by qualified

service personnel only.

-Disconnect appliance from electrical supply before beginning service.

-Be sure all grounding devices are connected when service is complete.

-Failure to observe the above warnings may result in severe electrical shock.

PIN 1

YELLOW

ORANGE

WHITE

BLACK

1 PURPLE

2 WHITE

3 GRN/YL STP

2 BROWN

1 BLUE

GREEN

BLACK

PLAIN

2 WHITE

GREEN

RIBBED

1 BLACK

WHITE

PURPLE

WHITE

GREEN W/YELLOW STRIPE

321

WHITE 11

ORANGE

RED

ORANGE

YELLOW 4

BLUE/BLACK STRIPE

BLUE/RED STRIPE

ORNG/RED STRIPE

1109

ORANGE

PIN 1

3 4

RED

MAIN BOARD

WHITE

BLACK

PURPLE

YELLOW

RED

ORANGE

WHITE

YELLOW

ORANGE/BLACK STRIPE

RED

BLUE/BLACK STRIPE

YELLOW

ORANGE

WHITE

RED

BLACK

YELLOW

ORANGE YELLOW

PIN 1

WHITE

JACKET CABLE (MARKED WITH BLUE STRIPE)

SENSOR

(REF CAB)

ORANGE

RED

PINK BLACK

(BEVERAGE CENTER ONLY)

UPPER REFRIGERATOR

LIGHT

WHITE

REF FAN MOTOR

RED

WHITE

ORANGE

RED

SENSOR (EVAP)

PINK

SWITCH LIGHT

WHITE

CORD

SUPPLY

JACKET CABLE (MARKED WITH 2 RED STRIPES)

(BEVERAGE CENTER ONLY)

MFG TEST TERMINALS

COMPRESSOR

POWER

CONDENSER FAN MOTOR

WIRING DIAGRAM MODEL UC-24B, UC-24R, UC-24RO

MAIN CONTROL BOARD DETAIL

SWITCH LIGHT

P/N 7002555 REV A

LIGHT TUBE

DISPLAY BOARD

PURPLE

Wire Diagrams & Schematics

Under Counter (UC-24) Series

10-4

#7003933 - Revision B - November, 2007

Page 60

-This wiring information is provided for use by qualified

service personnel only.

-Disconnect appliance from electrical supply before beginning service.

-Be sure all grounding devices are connected when service is complete.

-Failure to observe the above warnings may result in severe electrical shock.

PIN 1

RELAY

YELLOW

STARTING

RED

ORANGE

(WHEN

USED)

CAPACITOR

COMPRESSOR

REF LIGHT

SWITCH

WHITE

BLACK

PROTECTOR

PIN 1

THERMISTOR REFRIGERATOR

BLUE W/BLACK STRIPE

WHITE

ORANGE W/RED STRIPE

ORANGE

PURPLE

ORANGE

PIN 1

YELLOW

MAIN BOARD

PIN 1

ORANGE

PIN 1

WHITE

REF (TOP)

LIGHT

REF FAN MOTOR

OVERLOAD

CONDENSER FAN

RED

COMPRESSOR

RUNNING

MAIN BOARD

WHITE

MEMBRANE KEYPAD

THERMISTOR EVAPORATOR

NEUTRAL

HIGH VOLTAGE SCHEMATIC

115 VOLTS 60 CYCLES

DISPLAY BOARD

BLUE W/BLACK STRIPE

PIN 1

BLUE W/RED STRIPE

PIN 1

LOW VOLTAGE SCHEMATIC

PIN 1

LIGHTS

PINK

WHITE

REF LIGHT

SWITCH

LIGHT TUBE SWITCH

(UC-24B ONLY)

DISPLAY

P/N 7002555 REV A

WIRING SCHEMATIC MODEL UC24-B, UC-24R, UC-24RO

Wire Diagrams & Schematics

Under Counter (UC-24) Series

10-5

#7003933 - Revision B - November, 2007