Lennox 12J77 SPST Limit Switch Overview
The Lennox 12J77 is an OEM replacement limit switch designed to protect Lennox heating and HVAC systems from unsafe operating temperatures. With a Single-Pole Single-Throw (SPST) configuration, this limit switch opens the circuit at 60°F and closes at 35°F, providing reliable low-temperature safety control.
Key Features
- OEM Lennox replacement part — ensures proper fit and function
- SPST (Single-Pole Single-Throw) switching configuration
- Opens at 60°F (Op60F) to interrupt the circuit at the set point
- Closes at 35°F (Cl35F) to restore circuit continuity
- Designed for use in Lennox HVAC equipment requiring low-temperature limit protection
- Helps prevent equipment damage and unsafe operating conditions
Application
The 12J77 limit switch is a direct OEM replacement for compatible Lennox heating and air conditioning systems. Limit switches serve as critical safety devices, automatically interrupting electrical circuits when temperatures reach unsafe levels and restoring operation once safe temperatures return. Always verify compatibility with your specific Lennox unit model before installation.
Specifications
- Brand: Lennox
- Part Number: 12J77
- Switch Type: SPST (Single-Pole Single-Throw)
- Open Temperature: 60°F
- Close Temperature: 35°F
