Supco SHL517 Plenum Limit Switch L220-40F

The Supco SHL517 Plenum Limit Switch is a temperature-actuated control component used to monitor and regulate air handler plenum conditions. It responds to rising duct or plenum temperatures by opening at 220F and closing at 180F. In residential and commercial connections, it is installed within air handling units or ductwork where airflow temperature must be controlled in HVAC systems. The switch supports system safe operations by signaling abnormal heat conditions to internal components and maintains operational stability in forced-air systems.