Refrigeration Basics - Controls A commercial cooler in a hot environment which is constantly being accessed would tend to ice up. A Constant Cut In Control, also known as a beverage cooler control, forces an off cycle defrost at the end of each run cycle. The control will remain open until the evaporator has reached a temperature which indicates that any frost accumulated during the previous run cycle has been melted.[PDF] Installation, Operation and Troubleshooting Instructions All refrigerator or freezer electrical systems are internally grounded. Temperature Control Temperature control should be set to maintain a temperature of 38°F (3.3°C) to 40°F (4.4°C) for refrigerators, and 0°F (-17°C) to -5°F (-20.5°C) for freezers.