The 3L01-180 Snap Disc Limit Switch (White-Rodgers / Copeland Comfort Control) is an automatic reset temperature safety control designed to protect HVAC, heating, and refrigeration equipment from overheating. Featuring a 180°F fixed cut-out temperature and a typical 40°F differential, this open-on-rise switch interrupts the control circuit when temperatures exceed safe operating limits and automatically resets once the temperature drops to its reset point.

Cross-Reference

• 3L01-180
• 3L01180
• L180-40F
• 60T11 Series
• White-Rodgers 3L01-180
• Copeland Comfort Control 3L01-180

Direct OEM

White-Rodgers 3L01-180

Compatible Brands

• White-Rodgers
• Emerson
• Copeland
• York
• Coleman
• Luxaire
• Goodman
• Universal HVAC Applications

Application

Used in HVAC and refrigeration equipment to:

• Protect systems from overheating
• Open the control circuit at 180°F
• Automatically reset after cooling
• Protect compressors, heat exchangers, and control circuits
• Prevent damage from excessive operating temperatures
• Maintain safe equipment operation

Related Components

• Snap Disc Limit Switch
• High Limit Control
• Fan Switch
• Fan & Limit Control
• Furnace Control Board
• Blower Relay
• Transformer
• Temperature Sensor
• Contactor

Technician Notes

The 3L01-180 is an automatic reset, open-on-rise snap disc limit switch commonly used in HVAC and refrigeration applications. The contacts remain closed during normal operation and open when the sensing surface reaches 180°F. Once the temperature decreases by the switch differential, the contacts automatically reset.

Repeated limit trips often indicate restricted airflow, dirty coils, plugged filters, failing blower motors, blocked vents, excessive heat load, or other system issues that should be corrected before replacing the switch.

Common Symptoms of Failure

• Equipment shuts down on high temperature
• Open limit circuit fault
• Intermittent heating or cooling operation
• Safety lockout conditions
• No continuity through switch contacts
• Frequent nuisance trips
• Failure to restart properly
• Reduced system reliability

Installation Tips

1. Disconnect electrical power before servicing.
2. Verify temperature ratings and switch action match the original.
3. Confirm the switch is an "Open on Rise" design.
4. Mount securely to the original sensing location.
5. Inspect terminals for corrosion or overheating.
6. Check airflow and operating temperatures.
7. Test continuity before startup.
8. Verify complete system operation after installation.

Recommended Inspection Items

• Blower motor operation
• Air filter condition
• Coil cleanliness
• Electrical terminals
• Wiring harness condition
• Supply voltage
• Temperature rise across equipment
• Control board diagnostics
• Venting and airflow restrictions