High Pressure Safety Valve HVAC: Description and Operation
Refrigerant System ProtectionRefrigerant Pressure Sensor
The refrigerant system is protected against excessively high or low pressures by the refrigerant pressure sensor, located on the condenser. If the system pressure rises above, or falls below the specifications, the refrigerant pressure sensor detects the pressure inside the refrigerant line and sends the voltage signal to the ECM. ECM makes the A/C relay go OFF and stops the compressor when pressure on the high pressure side detected by refrigerant pressure sensor is over about 2,746 kPa (28 kg/sq.cm, 398 psi), psi or below about 177 kPa (1.8 kg/sq.cm, 26 psi).
Pressure Relief Valve
The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor. When the pressure of refrigerant in the system increases to an abnormal level [more than 3,727 kPa (38 kg/sq.cm, 540 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant into the atmosphere.