The Lennox 38M77 is an OEM high pressure switch engineered to protect refrigeration and air conditioning systems from dangerous overpressure conditions. With a cut-out pressure of 640 PSI and a cut-in (reset) pressure of 475 PSI, this switch provides reliable, automatic protection for compressors and refrigerant circuits.
How It Works
The high pressure switch continuously monitors system refrigerant pressure on the high side of the circuit. When pressure reaches the 640 PSI cut-out threshold, the switch opens the circuit to shut down the compressor, preventing equipment damage or failure. Once system pressure drops to the 475 PSI cut-in point, the switch resets and allows normal operation to resume.
Key Features
- OEM Lennox replacement part — direct fit for compatible Lennox equipment
- Cut-out pressure: 640 PSI
- Cut-in (reset) pressure: 475 PSI
- Protects compressors and refrigerant circuits from high-pressure damage
- Automatic reset operation for convenient service
- Durable construction for long-term reliability in demanding HVAC/R applications
Application
Designed as a direct OEM replacement for Lennox residential and light commercial HVAC systems. Always verify compatibility with your specific equipment model before installation. Consult the Lennox parts catalog or your equipment service manual to confirm proper fitment.
