Sub-Zero Under Counter Series Wiring Diagram
Model: UC-24C
Part Number: 7026634 Rev A
⚠️ WARNING: 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.
General Information
Please place this wiring diagram in the wiring diagram bag for future reference.
Wiring Diagram Overview
Component Connections:
- Sensors: EVAP (marked w/ green stripe), REF CAB (marked w/ 2 green stripes), REF (EVAP) (marked w/ blue stripe), REF (PVAR) (marked w/ 2 red stripes)
- Motors: REF FAN MOTOR, CONDENSER FAN MOTOR
- Heaters: DEFROST HEATER
- Boards: DISPLAY BOARD, MAIN BOARD
- Other Components: ICEMAKER, ICEMAKER SOLENOID (OPTIONAL), REF LIGHT, SWITCH LIGHT, COMPRESSOR
- Cables: JACKET CABLE
- Power: POWER SUPPLY CORD (L1, L2)
The diagram illustrates the flow of electrical connections between these components, including low voltage and high voltage circuits.
Main Control Board Summary
| Terminal | Circuit | Description | Function | Color | Terminal | Circuit | Description | Function | Color |
|---|---|---|---|---|---|---|---|---|---|
| P4-L2 | NEUTRAL | NEUTRAL INTO BOARD | NEUTRAL | WHITE | J5-8 | EVAP | EVAPORATOR | SENSES EVAP TEMP | BLUE/RED |
| P3-L1 | POWER IN | POWER INTO BOARD | POWER | BLACK | J5-7 | EVAP | EVAPORATOR | SENSES EVAP TEMP | ORANGE/RED |
| P1 | COMPRESSOR | COMPRESSOR | POWERS COMPRESSOR AND COND. FAN | PURPLE | J5-6,5 | NOT USED | NOT USED | NOT USED | - |
| P2 | DEFROST | DEFROST HEATER | POWERS DEFROST CIRCUIT | - | J5-4,3 | CAB | REF COMPARTMENT | SENSES REF CAB TEMP | BLUE/BLACK |
| J3-7 | LIGHTS | LIGHTS | POWERS LIGHTS | YELLOW | J5-2,1 | NOT USED | NOT USED | NOT USED | - |
| J3-6 | NOT USED | NOT USED | NOT USED | - | J6-3 | NOT USED | NOT USED | NOT USED | - |
| J3-5 | NOT USED | NOT USED | NOT USED | - | J6-2 | NOT USED | NOT USED | NOT USED | - |
| J3-4 | NOT USED | NOT USED | NOT USED | - | J6-1 | NOT USED | NOT USED | NOT USED | - |
| J3-3 | NOT USED | NOT USED | NOT USED | - | J4-6 | NOT USED | NOT USED | NOT USED | - |
| J3-2 | NOT USED | NOT USED | NOT USED | - | J4-5 | DISPLAY | DISPLAY WIRING | GROUND FOR DISPLAY BOARD POWER SUPPLY | ORANGE |
| J3-1 | FAN 1 | EVAP FAN | POWERS EVAP FAN | RED | J4-4 | DISPLAY | DISPLAY WIRING | SERIAL DATA TRANSMIT | YELLOW |
| J2-4 | NOT USED | NOT USED | NOT USED | - | J4-3 | DISPLAY | DISPLAY WIRING | SERIAL DATA RECEIVE | RED |
| J2-3 | DEF | DEFROST SENSOR | SENSES WHEN DEF HEATER SHUTS OFF | ORANGE | J4-2 | DISPLAY | DISPLAY WIRING | 12DC POWER SUPPLY FOR DISPLAY BOARD | GRAY/WHITE |
| J2-2 | R DOOR | REF DOOR LIGHT SENSE | SENSES IF LOWER DOOR OPEN | - | J4-1 | NOT USED | NOT USED | NOT USED | WHITE |
| J2-1 | NOT USED | NOT USED | NOT USED | - |
Main Control Board Detail
120 VOLT CIRCUITS:
- P4 (L2): Neutral
- P3 (L1): Power In
- P1: Compressor
- P2: Defrost
- J3-7: Lights
- J3-1: Fan 1 (Evap Fan)
Low Voltage Circuits:
- J5-8, J5-7: EVAP (Evaporator Sensor)
- J5-4,3: CAB (Ref Compartment Sensor)
- J2-3: DEF (Defrost Sensor)
- J2-2: R DOOR (Ref Door Light Sense)
- J4-5: DISPLAY (Display Wiring - Ground)
- J4-4: DISPLAY (Display Wiring - Serial Data Transmit)
- J4-3: DISPLAY (Display Wiring - Serial Data Receive)
- J4-2: DISPLAY (Display Wiring - 12DC Power Supply)
Other Connections:
- J6-3: Baffle Close
- J6-2: Baffle Open
- J6-1: Baffle Neutral
High Voltage Schematic
The high voltage schematic shows the connections for the COMPRESSOR, CONDENSER FAN, REF FAN MOTOR, DEFROST HEATER, and REF (TOP) LIGHT. It includes components like the RUNNING CAPACITOR, COMPRESSOR STARTING RELAY, and OVERLOAD PROTECTOR.
Key Components and Connections:
- Compressor: Powered by P1, connected to L1 and Neutral via overload protector and starting relay.
- Condenser Fan: Connected to Compressor circuit.
- Ref Fan Motor: Connected to Neutral and a specific terminal on the Main Board.
- Defrost Heater: Connected to P2 and Neutral.
- Ref (Top) Light: Powered by J3-7 (Lights) and connected to Neutral via the Ref Light Switch.
- Icemaker Valve: Connected to the Main Board and Neutral.
Low Voltage Schematic
The low voltage schematic details the connections for sensors, display, and control signals. It shows how the THERMISTOR EVAP, THERMISTOR REF CAB, THERMISTOR FRE CAB, and REF DOOR LIGHT SENSE connect to the Main Board and Display Board.
Key Components and Connections:
- Display Board: Connected to the Main Board via multiple terminals (J4, J3) for power, data transmission, and reception.
- Sensors: EVAP, CAB, and DEF sensors provide temperature readings to the Main Board.
- Ref Door Light Sense: Detects if the lower door is open.
- Ref Air Duct Baffle: Controlled via specific terminals on the Main Board.
Models Covered
This wiring diagram applies to Sub-Zero Under Counter Series models: UC-24R/RO & UC-24B.
Part Number: 7026638 Rev A
Document Revision: #7031931 - Revision A - June, 2014
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