White-Rodgers 3L11-120 Limit Switch

The White-Rodgers 3L11-120 is a specialized 1/2-inch bimetal disc limit switch designed for high-limit temperature protection in HVAC systems. Engineered for reliability, this SPST open on rise switch features a fixed cut-out range of 115°F to 125°F with a 30°F differential. As a 36T surface mount limit control, it utilizes a snap-acting bimetal disc that ensures high-speed contact separation, providing consistent thermal response for fan and limit applications. This model is an auto-reset limit switch, meaning it automatically re-engages once the temperature drops below the differential threshold, making it a critical component for maintaining system safety without manual intervention. Contractors frequently use the 3L11-120 as a direct OEM replacement heating limit for various furnace and air handling units, ensuring the equipment operates within safe thermal parameters. Its compact design and standard mounting allow for seamless integration during field service repairs.

• Precision Thermal Sensing: Fixed temperature settings between 115°F and 125°F provide accurate safety shutdowns.
• Reliable SPST Action: The Single Pole Single Throw configuration ensures a clean break upon reaching the set thermal limit.
• Automatic Reset Functionality: Reduces downtime by automatically restoring the circuit once the system cools by 30°F.
• Industry Standard Compatibility: Replaces common 1/2" bimetal disc controls, including various 36T series configurations.
• Durable Bimetal Construction: Designed for long-term cycling in high-demand residential and commercial heating applications.

What is the difference between an auto-reset and a manual reset limit switch?
The White-Rodgers 3L11-120 is an auto-reset switch, which automatically closes the circuit when the temperature drops. A manual reset requires a technician to physically depress a button after the unit has tripped.

Can I use this switch if my furnace requires a different temperature rating?
No, limit switches must be matched to the fixed temperature range specified by the equipment manufacturer to prevent safety hazards or premature system cycling.

Where is this limit control typically mounted?
This 1/2" bimetal disc is usually surface-mounted on the heat exchanger or within the airflow path where it can accurately monitor the system’s internal temperature.

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.