White-Rodgers 3L05-1 Limit Switch

The White-Rodgers 3L05-1 Limit Switch is a high-performance adjustable snap disc limit control engineered for precision high-limit protection in forced air heating systems. This SPST (Single Pole Single Throw) control operates on an open on rise logic, effectively breaking the circuit once the sensed temperature reaches the calibrated setpoint to prevent equipment overheating. Featuring an adjustable temperature range of 135 to 175 degrees F and a fixed 40-degree F differential, this versatile component allows technicians to dial in exact safety parameters, reducing the need to carry multiple fixed-temperature switches in the field. This unit is the recognized 3L05-1 direct replacement for 31614 and 3L05-4 models, utilizing the 74T11-310710 therm-o-disc style for consistent thermal response. Designed for a flanged airstream mount, it comes standard with 1/4-inch quick-connect terminals and is rated for 14.0A at 120VAC or 10.0A at 240VAC, ensuring compatibility with a wide range of residential and commercial HVAC equipment.

• Adjustable Setpoint: The 135°F to 175°F range provides flexibility for various furnace and heater applications, simplifying inventory management for service contractors.
• Reliable Safety Integration: The automatic reset limit switch ensures the system returns to operation once the 40°F temperature differential is met, minimizing unnecessary downtime.
• Universal Compatibility: Replaces obsolete parts including Lennox 31614 and various 74T11 snap disc configurations, making it a "truck stock" essential.
• Robust Electrical Ratings: Handles inductive motor loads up to 72A locked rotor at 120V, providing heavy-duty performance for blower limit applications.

Is the 3L05-1 a direct replacement for my fixed limit switch?
Yes, provided the original switch's opening temperature falls within the 135°F to 175°F window. The adjustable dial allow you to match the original OEM specification exactly.

What is the difference between open on rise and close on rise?
This model is an open on rise switch action, meaning it acts as a safety limit by breaking the electrical circuit when it gets too hot. A close on rise switch (like the 3F05-1) is typically used for fan control to start a blower when heat is detected.

Does this switch require a manual reset?
No, this is an automatic reset snap disc. It will automatically reset and close the circuit once the temperature drops 40°F below your selected setpoint.

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.