What is a common function of an outdoor ambient thermostat in a commercial split system air conditioner?

An outdoor ambient thermostat in a commercial split system air conditioner plays a crucial role in managing the operation of the system based on the external temperature conditions. One of its common functions is to turn on crankcase heat during low ambient temperatures.

This function is particularly important because, in cold weather conditions, refrigerant in the compressor can become too cold, leading to the risk of liquid refrigerant flooding the compressor during startup. By activating the crankcase heater, the thermostat helps maintain the compressor oil and refrigerant temperature, preventing the potential issues associated with low temperatures. Proper operation of the crankcase heater ensures that the compressor can optimize performance when the system starts up in cold conditions, thus protecting the equipment from damage and promoting energy efficiency.

This function is critical in maintaining the reliability and longevity of the air conditioning system. The other options, while related to different operational scenarios, do not specifically pertain to the primary function of an outdoor ambient thermostat in relation to crankcase management during low temperatures.