Supco L180-20 Limit Switch

When you are troubleshooting short-cycling or thermal cutout issues on the job site, the Supco L180-20 Limit Switch (Cross-reference 60T11-610073) is a reliable field-ready solution. This 3/4-inch bimetal snap disc is engineered for precision, featuring a fixed 180 degree F cutout temperature and a 160 degree F cut-in temperature. Designed with an open on rise switch action, it serves as a critical high-limit safety control that interrupts the burner circuit if the plenum temperature exceeds safe operating parameters. The auto-reset functionality ensures the system resumes normal operation once the heat exchanger cools to the 160°F differential. Built for high-demand environments, it utilizes welded construction to maintain the integrity of current-carrying components and supports up to 25 amps at 240VAC. The 1/4 inch quick disconnect terminals allow for rapid installation in furnace limit and dryer safety applications, providing the fast response time required by modern HVACR equipment.

Key Benefits for Contractors:

• Universal Compatibility: Direct replacement for 60T11 style 180-degree bimetal thermostats.
• Heavy-Duty Electrical Rating: Designed for single pole single throw (SPST) loads up to 25A 240VAC.
• Simplified Installation: Features standard 1/4" male spade terminals for secure, vibration-resistant connections.
• Industrial Build Quality: Enclosed construction protects bimetal elements from dust and debris in the airstream.

Common HVAC Technical Questions:

How do I test a limit switch with a multimeter?
With the power off, check for continuity across the terminals; at room temperature, this switch should be closed. If it stays open at room temperature, the internal bimetal disc is compromised.

What causes this switch to trip prematurely?
Repeated tripping is usually a symptom of restricted airflow, often caused by a clogged furnace filter, a failing blower motor, or restricted ductwork creating excessive static pressure.

Can I use this to replace a manual reset limit?
No. While the temperatures may match, a snap disc auto reset should only be used in applications where the original design specifies automatic reset cycles for safety. Always verify the manufacturer's sequence of operations.

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.