Lennox 38M78 Ambient Switch
This Lennox 38M78 Ambient Switch is a critical pressure-actuated component designed for head pressure control in low-ambient cooling applications. Engineered for precision, this low ambient pressure switch ensures reliable operation of your HVACR system when outdoor temperatures drop, preventing compressor slugging and maintaining the necessary pressure differential for efficient thermal transfer. The Lennox 38M7801 features a specific cut-in point of 450 PSI and a cut-out point of 250 PSI, allowing it to cycle the condenser fan motor effectively to stabilize the high-side pressure in R-410A systems.
Built for the rigors of field service, this OEM Lennox replacement part is rated for up to 600 PSI and operates on typical 120/240V pilot duty circuits. As a veteran-preferred HVAC pressure control switch, it provides the exact electrical and mechanical specifications required to keep commercial and residential units running within safe parameters during year-round operation. When diagnosing a condenser fan cycling issue or prepping a system for winter cooling requirements, the 38M78 offers the technical HVAC specifications and durability demanded by professional contractors.
Key Benefits
- Precision Pressure Regulation: High-accuracy 450 PSI rising (in) and 250 PSI falling (out) setpoints for consistent head pressure management.
- Broad Compatibility: Functions as a direct OEM fit for numerous Lennox and Allied units, ensuring seamless integration with existing wiring harnesses.
- Enhanced System Protection: Strategically cycles the condenser fan to prevent liquid refrigerant from returning to the compressor in cold weather.
- Industrial Grade Build: Designed to withstand vibration and environmental exposure in outdoor condensing units.
Common Questions
What is the function of the 450# in and 250# out settings?
The switch closes its contacts at 450 PSI to start the condenser fan and opens them at 250 PSI to stop the fan, maintaining the refrigerant head pressure required for proper expansion valve operation.
Can this switch be used with refrigerants other than R-410A?
While designed for the high-pressure curves of R-410A, always verify the pressure-temperature relationship and the switch’s 600 PSI maximum burst rating for your specific application before installation.
How do I identify a failing ambient switch?
Technicians typically check for the condenser fan failing to cycle during low outdoor temperatures or the compressor tripping on high pressure due to the switch failing to close at the 450 PSI setpoint.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
Original: $33.30
-65%$33.30
$11.65Lennox 38M78 Ambient Switch
This Lennox 38M78 Ambient Switch is a critical pressure-actuated component designed for head pressure control in low-ambient cooling applications. Engineered for precision, this low ambient pressure switch ensures reliable operation of your HVACR system when outdoor temperatures drop, preventing compressor slugging and maintaining the necessary pressure differential for efficient thermal transfer. The Lennox 38M7801 features a specific cut-in point of 450 PSI and a cut-out point of 250 PSI, allowing it to cycle the condenser fan motor effectively to stabilize the high-side pressure in R-410A systems.
Built for the rigors of field service, this OEM Lennox replacement part is rated for up to 600 PSI and operates on typical 120/240V pilot duty circuits. As a veteran-preferred HVAC pressure control switch, it provides the exact electrical and mechanical specifications required to keep commercial and residential units running within safe parameters during year-round operation. When diagnosing a condenser fan cycling issue or prepping a system for winter cooling requirements, the 38M78 offers the technical HVAC specifications and durability demanded by professional contractors.
Key Benefits
- Precision Pressure Regulation: High-accuracy 450 PSI rising (in) and 250 PSI falling (out) setpoints for consistent head pressure management.
- Broad Compatibility: Functions as a direct OEM fit for numerous Lennox and Allied units, ensuring seamless integration with existing wiring harnesses.
- Enhanced System Protection: Strategically cycles the condenser fan to prevent liquid refrigerant from returning to the compressor in cold weather.
- Industrial Grade Build: Designed to withstand vibration and environmental exposure in outdoor condensing units.
Common Questions
What is the function of the 450# in and 250# out settings?
The switch closes its contacts at 450 PSI to start the condenser fan and opens them at 250 PSI to stop the fan, maintaining the refrigerant head pressure required for proper expansion valve operation.
Can this switch be used with refrigerants other than R-410A?
While designed for the high-pressure curves of R-410A, always verify the pressure-temperature relationship and the switch’s 600 PSI maximum burst rating for your specific application before installation.
How do I identify a failing ambient switch?
Technicians typically check for the condenser fan failing to cycle during low outdoor temperatures or the compressor tripping on high pressure due to the switch failing to close at the 450 PSI setpoint.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
Product Information
Product Information
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Description
This Lennox 38M78 Ambient Switch is a critical pressure-actuated component designed for head pressure control in low-ambient cooling applications. Engineered for precision, this low ambient pressure switch ensures reliable operation of your HVACR system when outdoor temperatures drop, preventing compressor slugging and maintaining the necessary pressure differential for efficient thermal transfer. The Lennox 38M7801 features a specific cut-in point of 450 PSI and a cut-out point of 250 PSI, allowing it to cycle the condenser fan motor effectively to stabilize the high-side pressure in R-410A systems.
Built for the rigors of field service, this OEM Lennox replacement part is rated for up to 600 PSI and operates on typical 120/240V pilot duty circuits. As a veteran-preferred HVAC pressure control switch, it provides the exact electrical and mechanical specifications required to keep commercial and residential units running within safe parameters during year-round operation. When diagnosing a condenser fan cycling issue or prepping a system for winter cooling requirements, the 38M78 offers the technical HVAC specifications and durability demanded by professional contractors.
Key Benefits
- Precision Pressure Regulation: High-accuracy 450 PSI rising (in) and 250 PSI falling (out) setpoints for consistent head pressure management.
- Broad Compatibility: Functions as a direct OEM fit for numerous Lennox and Allied units, ensuring seamless integration with existing wiring harnesses.
- Enhanced System Protection: Strategically cycles the condenser fan to prevent liquid refrigerant from returning to the compressor in cold weather.
- Industrial Grade Build: Designed to withstand vibration and environmental exposure in outdoor condensing units.
Common Questions
What is the function of the 450# in and 250# out settings?
The switch closes its contacts at 450 PSI to start the condenser fan and opens them at 250 PSI to stop the fan, maintaining the refrigerant head pressure required for proper expansion valve operation.
Can this switch be used with refrigerants other than R-410A?
While designed for the high-pressure curves of R-410A, always verify the pressure-temperature relationship and the switch’s 600 PSI maximum burst rating for your specific application before installation.
How do I identify a failing ambient switch?
Technicians typically check for the condenser fan failing to cycle during low outdoor temperatures or the compressor tripping on high pressure due to the switch failing to close at the 450 PSI setpoint.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
