The external equalizer port monitors the actual pressure at the evaporator outlet

ensuring the heat exchanger is protected against overheating conditions caused by airflow obstructions or blower failure

Key Benefits Adjustable Set Point: Field-adjustable from 135°F to 175°F to match a wide variety of equipment specifications

providing the fast

this relay handles steady-state currents up to 10 Amps

Lochinvar & A.O. Smith 100074280 Limit Switch 318518-761 The external equalizer port monitorsThe Lochinvar & A. O. Smith 100074280 High Limit Switch is a critical safety component engineered to provide thermal protection in high efficiency heating systems. Designed as a genuine OEM replacement part, this switch monitors the internal temperature of the heat exchanger or burner door to prevent unsafe operating conditions. If temperatures exceed the factory defined safety threshold, the 100074280 triggers an immediate system lockout to mitigate