MARS 39230 Limit
The MARS 39230 Adjustable Limit Switch is a critical high-temperature safety control designed for precise HVAC furnace limit monitoring. Engineered for professional contractors, this SPST open on rise switch provides dependable upper-limit protection in furnaces, unit heaters, and commercial ductwork. Featuring a versatile 210-250 degree Fahrenheit adjustable range, it allows technicians to calibrate the exact cutout point required for specific heat exchanger specifications, significantly reducing the necessity for carrying multiple fixed-temp controls in the service van. The 40-degree fixed differential is factory-set to ensure stable cycle times and prevent the rapid short-cycling or nuisance trips common in high-static applications. Built with a rugged bi-metal sensing element and 1/4-inch quick-connect terminals, this 390 series limit switch integrates seamlessly into existing safety strings. The integral two-hole oval mounting flange facilitates a secure flush mount against the plenum or equipment cabinet, ensuring the bimetal plate maintains direct thermal contact for reactive, real-time temperature sensing.
Key Benefits- Adjustable Temperature Range: High-limit settings from 210°F to 250°F allow for flexible hardware matching across various OEM furnace brands.
- Universal Mounting: The integral oval flange design supports standard 2-inch mounting footprints common in residential and light commercial units.
- Reliable Switching: SPST action (Single Pole Single Throw) opens the circuit on temperature rise to immediately interrupt the gas valve or ignition control circuit.
- Optimized Differential: The fixed 40°F differential ensures the system cools sufficiently before resetting, protecting the heat exchanger from thermal stress.
- Broad Compatibility: Rated for 120/240V applications, making it a "truck stock" essential for HVAC high-limit replacement.
What does 'open on rise' mean for this limit switch?
In HVAC safety circuits, 'open on rise' signifies that the electrical contacts break (interrupting power) when the sensed temperature hits the user-defined setpoint (210°F-250°F), effectively shutting down the burners if the furnace overheats.
How do I adjust the temperature setting on the MARS 39230?
Technicians can calibrate the limit by turning the visible indicator dial on the face of the control to the specified cutout temperature required by the equipment manufacturer.
Can this replace a fixed-temperature snap disc?
Yes, as long as the original part's required cutout temperature falls within the 210°F to 250°F range and the mounting footprint is compatible with the 2-inch oval flange.
This item is not eligible for free shipping.
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.
MARS 39230 Limit
The MARS 39230 Adjustable Limit Switch is a critical high-temperature safety control designed for precise HVAC furnace limit monitoring. Engineered for professional contractors, this SPST open on rise switch provides dependable upper-limit protection in furnaces, unit heaters, and commercial ductwork. Featuring a versatile 210-250 degree Fahrenheit adjustable range, it allows technicians to calibrate the exact cutout point required for specific heat exchanger specifications, significantly reducing the necessity for carrying multiple fixed-temp controls in the service van. The 40-degree fixed differential is factory-set to ensure stable cycle times and prevent the rapid short-cycling or nuisance trips common in high-static applications. Built with a rugged bi-metal sensing element and 1/4-inch quick-connect terminals, this 390 series limit switch integrates seamlessly into existing safety strings. The integral two-hole oval mounting flange facilitates a secure flush mount against the plenum or equipment cabinet, ensuring the bimetal plate maintains direct thermal contact for reactive, real-time temperature sensing.
Key Benefits- Adjustable Temperature Range: High-limit settings from 210°F to 250°F allow for flexible hardware matching across various OEM furnace brands.
- Universal Mounting: The integral oval flange design supports standard 2-inch mounting footprints common in residential and light commercial units.
- Reliable Switching: SPST action (Single Pole Single Throw) opens the circuit on temperature rise to immediately interrupt the gas valve or ignition control circuit.
- Optimized Differential: The fixed 40°F differential ensures the system cools sufficiently before resetting, protecting the heat exchanger from thermal stress.
- Broad Compatibility: Rated for 120/240V applications, making it a "truck stock" essential for HVAC high-limit replacement.
What does 'open on rise' mean for this limit switch?
In HVAC safety circuits, 'open on rise' signifies that the electrical contacts break (interrupting power) when the sensed temperature hits the user-defined setpoint (210°F-250°F), effectively shutting down the burners if the furnace overheats.
How do I adjust the temperature setting on the MARS 39230?
Technicians can calibrate the limit by turning the visible indicator dial on the face of the control to the specified cutout temperature required by the equipment manufacturer.
Can this replace a fixed-temperature snap disc?
Yes, as long as the original part's required cutout temperature falls within the 210°F to 250°F range and the mounting footprint is compatible with the 2-inch oval flange.
This item is not eligible for free shipping.
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.
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Description
The MARS 39230 Adjustable Limit Switch is a critical high-temperature safety control designed for precise HVAC furnace limit monitoring. Engineered for professional contractors, this SPST open on rise switch provides dependable upper-limit protection in furnaces, unit heaters, and commercial ductwork. Featuring a versatile 210-250 degree Fahrenheit adjustable range, it allows technicians to calibrate the exact cutout point required for specific heat exchanger specifications, significantly reducing the necessity for carrying multiple fixed-temp controls in the service van. The 40-degree fixed differential is factory-set to ensure stable cycle times and prevent the rapid short-cycling or nuisance trips common in high-static applications. Built with a rugged bi-metal sensing element and 1/4-inch quick-connect terminals, this 390 series limit switch integrates seamlessly into existing safety strings. The integral two-hole oval mounting flange facilitates a secure flush mount against the plenum or equipment cabinet, ensuring the bimetal plate maintains direct thermal contact for reactive, real-time temperature sensing.
Key Benefits- Adjustable Temperature Range: High-limit settings from 210°F to 250°F allow for flexible hardware matching across various OEM furnace brands.
- Universal Mounting: The integral oval flange design supports standard 2-inch mounting footprints common in residential and light commercial units.
- Reliable Switching: SPST action (Single Pole Single Throw) opens the circuit on temperature rise to immediately interrupt the gas valve or ignition control circuit.
- Optimized Differential: The fixed 40°F differential ensures the system cools sufficiently before resetting, protecting the heat exchanger from thermal stress.
- Broad Compatibility: Rated for 120/240V applications, making it a "truck stock" essential for HVAC high-limit replacement.
What does 'open on rise' mean for this limit switch?
In HVAC safety circuits, 'open on rise' signifies that the electrical contacts break (interrupting power) when the sensed temperature hits the user-defined setpoint (210°F-250°F), effectively shutting down the burners if the furnace overheats.
How do I adjust the temperature setting on the MARS 39230?
Technicians can calibrate the limit by turning the visible indicator dial on the face of the control to the specified cutout temperature required by the equipment manufacturer.
Can this replace a fixed-temperature snap disc?
Yes, as long as the original part's required cutout temperature falls within the 210°F to 250°F range and the mounting footprint is compatible with the 2-inch oval flange.
This item is not eligible for free shipping.
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.
