Supco LD140 SPDT Limit Switch L140-20F

The Supco LD140 SPDT Limit Switch is a temperature-actuated control component used in furnace and heating equipment to monitor and regulate operating conditions. It changes electrical state when temperatures reach a preset range, around L140F to 20F differentially, allowing system response to heating limits or cooling recovery conditions. It is commonly used in residential and light commercial heating assemblies within HVAC systems where temperature-based circuit switching is required. Within the control system, it supports safety regulation, operational control, and system protection by enabling or interrupting electrical signals based on thermal conditions during normal and abnormal operating cycles.