Copeland Comfort Control (White Rodgers) 3L09-27 Limit Switch

The Copeland Comfort Control (White Rodgers) 3L09-27 Limit Switch is a critical safety component engineered for precise thermal management in high-demand HVAC and refrigeration systems. This board-mounted 1/2" bimetal disc limit switch features a fixed open temperature of 220°F and a fixed close temperature of 200°F, providing a consistent 20°F differential for equipment protection. Designed with open on rise switch action, the 3L09-27 ensures immediate circuit interruption during over-temperature conditions, while the auto reset functionality allows the system to resume operation once the temperature drops below the set point. With a 1.87" insertion length, this compact switch is a direct 3L09-27 cross for S1-026-32588-005, making it a versatile replacement part for furnace high-limit applications and industrial temperature monitoring where board-level mounting is required.

Key Benefits for Technicians:

• Universal Compatibility: Serves as a direct replacement for S1-026-32588-005 and many White Rodgers 3L09 series applications.
• High-Limit Protection: Precisely calibrated 220 degree F open temperature prevents heat exchanger damage and unsafe operating conditions.
• Reliable Resets: The automatic reset feature eliminates unnecessary service calls for manual intervention after temporary thermal spikes.
• Streamlined Installation: Designed for board-mounted configurations with a standard 1.87-inch depth for quick field replacement.
• Industrial Grade Durability: Built with a 1/2 inch bimetal disc to withstand high-cycling environments in both residential and commercial units.

Common Questions & Technical Insights:

What is the difference between this and a manual reset switch?
The 3L09-27 is an auto reset limit switch, meaning it will automatically close the circuit once the temperature cools to 200°F. Manual reset switches require a physical button press, typically required by local codes for rollout switches rather than primary limits.

Can this be used in place of a different insertion length?
It is critical to maintain the 1.87" insertion length to ensure the bimetal disc sits in the correct airflow path. Using a shorter or longer probe may result in inaccurate temperature sensing and premature tripping.

What causes a 220 degree F limit switch to trip?
Frequent tripping of a high limit switch usually indicates restricted airflow, such as a clogged filter, a failing blower motor, or an oversized furnace for the existing ductwork.

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.