What is the purpose of a low and high pressure switch in an AC system?
What is the purpose of a low and high pressure switch in an AC system? A high pressure switch (HPS) and a low pressure switch (LPS) are protective devices for the compressor and refrigeration circuit. The high pressure switch monitors the system for an inoperative outdoor motor, and/or a dirty/restricted condenser (outdoor) coil. What should the low side of the air conditioner pressure be? The low side pressure in your air conditioning system should drop down significantly when your engine is running and your AC compressor is cycling on. When the compressor shuts off or you turn your car off...