Lennox 99M99 Pressure Switch
As a service-ready high pressure switch for diagnostic and repair calls, the Lennox 99M99 is a critical safety component designed for high-side refrigerant monitoring. This genuine Lennox replacement part is engineered to actuate at 590 PSI and features an automatic reset at 418 PSI, ensuring the compressor is protected against catastrophic over-pressure conditions common in R-410A systems. Built with 106-inch leads and rated for 120/240 VAC (375 VA), this normally closed (N.C.) switch satisfies the rigid electrical requirements of Lennox, Armstrong, and Ducane heat pump and air conditioning units. Its small-body design and 1/4" SAE female flare connection allow for a direct-fit install without requiring heavy modifications to the liquid or discharge lines. Professional technicians rely on this refrigerant pressure safety switch to restore system integrity and maintain OEM operating specifications.
Key Benefits
- Precise 590/418 PSI Calibration: Engineered specifically for high-pressure R-410A applications to prevent compressor damage.
- OEM Compatibility: Direct replacement for part numbers 99M99, 100087-01, and R100324-01 across Lennox family brands.
- Extended 106" Lead Wires: Simplifies routing to the control board or contactor in large-chassis outdoor units.
- Gold Flash Contacts: Provides reliable electrical continuity and switching even in demanding environmental conditions.
- Durable Construction: Built to withstand high-vibration environments typical of HVACR compressor compartments.
Common Questions
Is the 99M99 an automatic or manual reset switch?
This is an automatic reset switch. It trips the circuit when the high-side pressure hits 590 PSI and restores the connection once pressure drops back to 418 PSI.
What refrigerant systems is this compatible with?
While typically used in high-pressure R-410A systems due to its 590 PSI trip point, always verify your specific equipment’s service manual for the required pressure setpoints.
Can this replace a three-wire switch?
No, the 99M99 is a two-wire, normally closed switch. If your system requires a three-wire configuration for a control board signal, this component will not be a direct electrical match.
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: $21.20
-65%$21.20
$7.42Lennox 99M99 Pressure Switch
As a service-ready high pressure switch for diagnostic and repair calls, the Lennox 99M99 is a critical safety component designed for high-side refrigerant monitoring. This genuine Lennox replacement part is engineered to actuate at 590 PSI and features an automatic reset at 418 PSI, ensuring the compressor is protected against catastrophic over-pressure conditions common in R-410A systems. Built with 106-inch leads and rated for 120/240 VAC (375 VA), this normally closed (N.C.) switch satisfies the rigid electrical requirements of Lennox, Armstrong, and Ducane heat pump and air conditioning units. Its small-body design and 1/4" SAE female flare connection allow for a direct-fit install without requiring heavy modifications to the liquid or discharge lines. Professional technicians rely on this refrigerant pressure safety switch to restore system integrity and maintain OEM operating specifications.
Key Benefits
- Precise 590/418 PSI Calibration: Engineered specifically for high-pressure R-410A applications to prevent compressor damage.
- OEM Compatibility: Direct replacement for part numbers 99M99, 100087-01, and R100324-01 across Lennox family brands.
- Extended 106" Lead Wires: Simplifies routing to the control board or contactor in large-chassis outdoor units.
- Gold Flash Contacts: Provides reliable electrical continuity and switching even in demanding environmental conditions.
- Durable Construction: Built to withstand high-vibration environments typical of HVACR compressor compartments.
Common Questions
Is the 99M99 an automatic or manual reset switch?
This is an automatic reset switch. It trips the circuit when the high-side pressure hits 590 PSI and restores the connection once pressure drops back to 418 PSI.
What refrigerant systems is this compatible with?
While typically used in high-pressure R-410A systems due to its 590 PSI trip point, always verify your specific equipment’s service manual for the required pressure setpoints.
Can this replace a three-wire switch?
No, the 99M99 is a two-wire, normally closed switch. If your system requires a three-wire configuration for a control board signal, this component will not be a direct electrical match.
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
Shipping & Returns
Shipping & Returns
Description
As a service-ready high pressure switch for diagnostic and repair calls, the Lennox 99M99 is a critical safety component designed for high-side refrigerant monitoring. This genuine Lennox replacement part is engineered to actuate at 590 PSI and features an automatic reset at 418 PSI, ensuring the compressor is protected against catastrophic over-pressure conditions common in R-410A systems. Built with 106-inch leads and rated for 120/240 VAC (375 VA), this normally closed (N.C.) switch satisfies the rigid electrical requirements of Lennox, Armstrong, and Ducane heat pump and air conditioning units. Its small-body design and 1/4" SAE female flare connection allow for a direct-fit install without requiring heavy modifications to the liquid or discharge lines. Professional technicians rely on this refrigerant pressure safety switch to restore system integrity and maintain OEM operating specifications.
Key Benefits
- Precise 590/418 PSI Calibration: Engineered specifically for high-pressure R-410A applications to prevent compressor damage.
- OEM Compatibility: Direct replacement for part numbers 99M99, 100087-01, and R100324-01 across Lennox family brands.
- Extended 106" Lead Wires: Simplifies routing to the control board or contactor in large-chassis outdoor units.
- Gold Flash Contacts: Provides reliable electrical continuity and switching even in demanding environmental conditions.
- Durable Construction: Built to withstand high-vibration environments typical of HVACR compressor compartments.
Common Questions
Is the 99M99 an automatic or manual reset switch?
This is an automatic reset switch. It trips the circuit when the high-side pressure hits 590 PSI and restores the connection once pressure drops back to 418 PSI.
What refrigerant systems is this compatible with?
While typically used in high-pressure R-410A systems due to its 590 PSI trip point, always verify your specific equipment’s service manual for the required pressure setpoints.
Can this replace a three-wire switch?
No, the 99M99 is a two-wire, normally closed switch. If your system requires a three-wire configuration for a control board signal, this component will not be a direct electrical match.
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.
