Supco SHL503 Plenum Limit Switch L190-40F

The Supco SHL503 Plenum Limit Switch is a temperature-sensitive safety control designed to monitor heat levels within the furnace plenum of compatible heating equipment. It is calibrated to open at 190F and close at 150F, interrupting the electrical circuit when temperatures exceed the preset limit and automatically restoring operation after the system cools down. It is mounted in the plenum area to assist in regulating safe operating temperatures during heating cycles in HVAC systems. It supports proper equipment protection, prevents excessive heat buildup and ensure consistent operation by monitoring temperature conditions throughout normal furnace use.