White-Rodgers 3L09-23 Limit Switch

The White-Rodgers 3L09-23 is a high-performance board mount limit control engineered for critical temperature management in forced-air systems. This 1/2" bimetal disc limit switch features a 3.12" insertion length, making it an ideal choice for placement in the air stream where rapid thermal response is required. Designed with Open on Rise switch action, the SPST contacts are factory-calibrated to open at a fixed 170°F and automatically close at 150°F. This auto reset limit switch ensures system safety by interrupting the circuit when excessive plenum temperatures are reached, preventing equipment damage without the need for manual intervention.

Built as a direct replacement limit switch for many OEM furnace and HVAC applications, the White-Rodgers 3L09-23 provides high-speed contact separation to minimize electrical arcing and extend the operational life of the unit. The board-mounted configuration allows for secure installation on circuit boards, while the therm-o-disc technology offers precise thermal cycling. For contractors, this part combines a 20-degree differential with robust inductive and resistive electrical ratings to ensure compatibility with standard HVAC high-limit safety circuits.

• Precision Thermal Sensing: Features a 1/2" bimetal disc for high-speed contact separation and rapid response to temperature spikes.
• Optimized Insertion Depth: The 3.12" insertion length ensures the sensor is properly positioned within the plenum for accurate air temperature sampling.
• Reliable Safety Integration: Fixed 170°F open temperature and auto reset functionality provide consistent high-limit protection for furnace blowers and heaters.
• Rugged Electrical Specs: Rated for up to 15.0A resistive at 120VAC, accommodating the demands of professional HVACR control systems.

Is the reset on the 3L09-23 manual or automatic?
This model features an auto reset, meaning it will automatically close the circuit once the temperature cools back down to 150°F.

What is the cut-out temperature for this part?
The White-Rodgers 3L09-23 is calibrated to open the circuit at a fixed 170°F and is not adjustable.

Can I use this as a direct replacement for other board-mounted limits?
Yes, provided the insertion length of 3.12 inches and the 170/150 temperature profile match your specific HVAC equipment specifications.

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.