Kold-Draft GT350 Service Manual

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #1 Water Fill

Bin thermostat closed; Switch in “ice” position; Contactor closed; Water plate closed (pump & defrost switch up)

Liquid level control is low, actuator thermostat warm—power to the water valve. Pump and defrost switch up (water plate closed)—power to the
water pump.

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #2 Water Fill Complete—Evaporator Temperature Above 26°F.)

Bin thermostat closed; Switch in “ice” position; Contactor closed; Water plate closed (pump & defrost switch up)

Liquid level control high—power off to the water valve. Pump and defrost switch up (water plate closed)—power to the water pump. Actuator
thermostat is warm.

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #3 Ice Forming—Evaporator Temperature Below 26°F.)

Bin thermostat closed; Switch in “ice” position; Contactor closed; Water plate closed (pump & defrost switch up)

Liquid level control high—power off to the water valve. Pump and defrost switch up (water plate closed)—power to the water pump. Actuator
thermostat switches cold.

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #4 Defrost- Start of Defrost

Bin thermostat closed; Switch in “ice” position; Contactor closed; Water plate closed (pump & defrost switch up)

Liquid level control switches to low—triggers defrost. Actuator switch up—power to water valve. Actuator thermostat cold—power to defrost valve,
power to actuator motor (motor turns CCW). Pump and defrost switch up (water plate closed)—power to water pump.

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #5 Defrost- Water Plate Lowering

Bin thermostat closed; Switch in “ice” position; Contactor closed; Water plate open (pump & defrost switch down)

Liquid level control switch low. Actuator switch up—power to water valve. Actuator thermostat cold—power to defrost valve, power to actuator
motor (actuator switch up, motor rotation CCW).

Pump and defrost switch down (water plate open)—no power to water pump.

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #6 Defrost- Water Plate Full Open

Bin thermostat closed; Switch in “ice” position; Contactor closed; Water plate open (pump & defrost switch down)

Liquid level control switch low. Actuator switch down—power off to actuator motor and water valve. Actuator thermostat cold—power to defrost
valve. Pump and defrost switch down (water plate open)—no power to water pump.

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #7 End of Defrost- Water Plate Closing

Bin thermostat closed; Switch in “ice” position; Contactor closed; Water plate open (pump & defrost switch down)

Liquid level control switch low. Actuator thermostat switch warm—power to water valve and actuator motor (actuator switch down, motor rotation
CW). Pump and defrost switch down (water plate open)—power to defrost valve, no power to water pump.

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #8 Defrost Ending- Water Plate Almost Closed

Bin thermostat closed; Switch in “ice” position; Contactor closed; Water plate almost closed (pump & defrost switch up)

Liquid level control switch low. Actuator thermostat switch warm—power to water valve and actuator motor (actuator switch down, motor rotation
CW). Actuator switch down—power to defrost valve.

Pump and defrost switch up (water plate almost closed)—power to water pump.

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #9 End of Defrost- Water Plate Closed

Bin thermostat closed; Switch in “ice” position; Contactor closed; Water plate closed (pump & defrost switch up)

Liquid level control switch low. Actuator thermostat switch warm—power to water valve. Actuator switch up—power off to actuator motor and
defrost valve. Pump and defrost switch up (water plate closed)—power to water pump.

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #10 Bin Full- Bin Thermostat Open

Bin thermostat open; Switch in “ice” position; Contactor open; Water plate closed or open

Bin thermostat opens when ice contacts bulb tube—no power to components.

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #11 Abnormal Opening of Water Plate

Bin thermostat closed; Switch in “ice” position; Contactor closed; Water plate cannot close (pump & defrost switch down)

Liquid level control switch low. Actuator thermostat switch warm—power to water valve. Actuator switch is pushed up—but power is maintained to
actuator motor by pump and defrost switch. Pump and defrost switch cannot be pushed up (water plate obstructed)—red circuit remains energized
and water plate re-opens—power to defrost valve, no power to water pump.

SEQUENTIAL CIRCUIT DIAGRAM – GT350 MODELS

Diagram #12 Wash Mode

Bin thermostat closed; Switch in “wash” position; Contactor open; Water plate closed (pump & defrost switch up)

Liquid level control switch high. Actuator thermostat switch warm—power to water valve. Actuator switch up—power off to actuator motor. Pump
and defrost switch up (water plate closed)—power to water pump, no power to defrost valve. If liquid level control switch low, power to water valve.