3L09-11 Copeland Comfort Control (White Rodgers) Board Mount Limit Control 210F
3L09-11 Copeland Comfort Control (White Rodgers) Board Mount Limit Control 210F
The 3L09-11 Board Mount Limit Control (White-Rodgers / Copeland Comfort Control) is an automatic reset temperature safety switch designed to protect HVAC equipment, control boards, transformers, and electrical compartments from excessive temperatures. Featuring a 210°F fixed open temperature, this compact board-mounted bimetal limit switch interrupts the circuit when overheating conditions occur and automatically restores operation after cooling, helping protect sensitive electrical components and improve equipment reliability.
Cross-Reference
- 3L09-11
- 3L0911
- L210F
- White-Rodgers 3L09-11
- Copeland Comfort Control 3L09-11
- 74T Series Board Mount Limit Control
Direct OEM
White-Rodgers 3L09-11
Compatible Brands
- White-Rodgers
- Emerson
- Copeland
- York
- Coleman
- Luxaire
- Goodman
- Rheem
- Universal HVAC Applications
Application
Used in HVAC and electrical equipment to:
- Protect control boards from overheating
- Interrupt safety circuits at elevated temperatures
- Automatically restore operation after cooling
- Protect transformers and electrical enclosures
- Prevent temperature-related component failures
- Provide automatic thermal protection
Related Components
- Board Mount Limit Switch
- Snap Disc Thermostat
- Furnace Control Board
- Transformer
- Blower Relay
- High Limit Control
- Temperature Sensor
- Safety Cutoff Switch
- Electrical Control Assembly
Technician Notes
The 3L09-11 is an automatic reset, open-on-rise board mount limit control utilizing a compact bimetal sensing disc. Under normal operating conditions, the contacts remain closed and open when the sensing surface reaches 210°F, interrupting the circuit to prevent overheating. Once temperatures drop below the switch reset point, the contacts automatically reclose and restore normal operation.
Board-mounted limit controls are commonly used in electrical compartments, transformer protection circuits, blower assemblies, control boards, and OEM HVAC equipment where dependable overtemperature protection is required in a compact footprint.
Common Symptoms of Failure
- Equipment shuts down unexpectedly
- Open safety circuit faults
- Intermittent operation
- Repeated high-temperature shutdowns
- Control board overheating faults
- No continuity through switch contacts
- Failure to reset properly
- Electrical compartment overheating
Installation Tips
- Disconnect power before servicing.
- Verify the replacement temperature rating matches the original component.
- Confirm switch action is Open on Rise.
- Mount securely in the original location.
- Inspect terminals for corrosion or heat damage.
- Verify proper airflow around electrical components.
- Check continuity after installation.
- Test operation through a complete equipment cycle.
Recommended Inspection Items
- Control board condition
- Transformer temperature
- Wiring harness connections
- Electrical terminals
- Blower motor operation
- Airflow restrictions
- Ventilation around controls
- Relay condition
- Equipment operating temperatures
