ActronAir High Pressure Switch R22 800L/12S protects the R22 refrigerant circuit on Classic Series residential split ducted systems by cutting power to the compressor when condensing pressure reaches 800 LPa, with a manual reset at 12 seconds to prevent rapid compressor cycling on intermittent high-pressure faults. A failed open high pressure switch prevents the system from operating; a failed closed switch removes the compressor's primary over-pressure protection, creating a risk of compressor and refrigerant circuit damage in high-ambient or restricted-airflow conditions. Isolate power and recover refrigerant before replacing any refrigerant circuit pressure switches.