Re: How do I turn A/C compressor off
All Air Conditioning Systems will turn the Compressor "Off" if/when the Evaporator temperature falls below approximately 28*F-30*F. This is done by directly measuring the temperature of the Evaporator or measuring the Low Side Refrigerant Pressure. Either way, the reason is to prevent the moisture that condenses out of the air and forms on the Evaporator from freezing. The reason the Evaporator can be run at temperatures slightly below 32*F is that the incoming air flow contains sufficient heat that the water will droplets will fall off of the Evaporator before the Latent Heat of Fusion can be removed and the water freezes. You do not want water to freeze on an Evaporator becuase it will: 1.) Block the flow of air, and more importantly 2.) Because water expands when it freezes; it will literally rip an Evaporator apart if allowed to form in sufficient amounts on the Evaporator.