Proper initialization of your Polar King walk-in cooler or freezer is essential to maintain efficiency and prolong the lifespan of your unit. This guide outlines the recommended safe start procedures to ensure your equipment operates at peak performance.
Adjustable Thermostat Settings
Each Polar King unit comes equipped with an adjustable thermostat located on the lower right-hand side of the evaporator coil inside the walk-in. Units are preset at the factory to the temperature specified by the customer. While minor adjustments can be made to suit specific needs, it’s advisable not to set the temperature lower than necessary to avoid unnecessary power consumption.
- Recommended Cooler Temperature: +34°F to +37°F
- Recommended Freezer Temperature: 0°F to -10°F for frozen food; -10°F to -15°F for ice cream
Initial Safe Start Procedures
For Coolers
When starting the walk-in cooler refrigeration system for the first time, the following sequence occurs:
- Thermostat Activation: The thermostat signals the need for refrigeration.
- Solenoid Valve Operation: The liquid line solenoid valve opens, allowing refrigerant flow.
- Compressor Activation: The pressure control completes the circuit, activating the condensing unit.
- Thermostat Satisfaction: Once the desired temperature is reached, the solenoid valve closes, and the compressor pumps down and shuts off. The evaporator fan continues to run.
Caution: Do not set the cooler temperature below 32°F to prevent potential damage.
For Freezers
Upon initial start-up of the freezer system:
- Thermostat Activation: The thermostat signals the need for refrigeration.
- Solenoid Valve Operation: The liquid line solenoid valve opens, permitting refrigerant flow.
- Compressor Activation: The pressure control completes the circuit, starting the condensing unit.
- Fan Delay: Evaporator fans are delayed by the defrost termination thermostat and will not operate until the coil temperature reaches approximately +20°F.
- Thermostat Satisfaction: Once the set temperature is achieved, the solenoid valve closes, and the compressor pumps down and stops. The evaporator fan remains operational.
Note: Fans may cycle on and off two or three times until the room temperature stabilizes.
Defrost Cycles
Cooler Defrost
Defrosting in coolers occurs during the refrigeration off cycle. Four defrost cycles per day are programmed at the factory (4 a.m., 10 a.m., 4 p.m., and 10 p.m.). Adjustments to these times can be made to align with your operational schedule. A slight rise in interior temperature during defrost is normal; the unit will promptly return to the set operating temperature after the cycle.
Freezer Defrost (Time Initiated – Temperature Terminated)
Freezers require defrosting after approximately six hours of operation to remove frost from the evaporator coil. The factory sets four defrost cycles daily (4 a.m., 10 a.m., 4 p.m., and 10 p.m.), which can be modified as needed. During defrost, the interior temperature may increase by 10°F to 20°F; however, this will not affect the stored products, and normal temperatures will resume post-cycle.
The defrost sequence is as follows:
- Cycle Initiation: The timer initiates the defrost cycle.
- Solenoid Valve Closure: The liquid line solenoid valve closes, evaporator fans stop, and defrost heaters are energized.
- Compressor Shutdown: After pumping down, the compressor stops.
- Frost Removal: Heaters warm the coil, melting frost, and the termination thermostat trips at the set temperature.
- Cycle Termination: The defrost cycle ends, the solenoid valve opens, and heaters deactivate.
- Refrigeration Resumption: The compressor restarts the refrigeration cycle.
- Fan Reactivation: Evaporator fans remain off until the coil temperature reaches approximately 20°F.
If the termination thermostat does not conclude the defrost cycle, a timer fail-safe will end it after 30 minutes.
By adhering to these safe start procedures, you can ensure the efficient and reliable operation of your Polar King walk-in cooler or freezer.
