This lead-free atmospheric vacuum breaker features a durable brass body and a 1/2-inch female NPT connection

What is the purpose of the dual SPDT contacts

Key Benefits Fail-Safe Security: True mechanical spring return ensures the system returns to a safe position during power loss

SPDT Output: Versatile switching capabilities for both low-level shutdown and high-level alarm functions

this 12" wide by 8" high rectangular unit utilizes a counter-balanced weighted arm to automatically bleed off excess static pressure when zone dampers close

Lennox 11J12 Pressure Switch 323613-751 This lead-free atmospheric vacuum breakerEnsure your combustion air system is operating within manufacturer parameters with the Lennox 11J12 Pressure Switch. This critical safety component is a high altitude specific differential switch designed for Lennox furnace repair and maintenance, featuring a factory set . 85" WC pressure switch actuation point. Engineering for precise draft proving, this part monitors the static pressure within the inducer housing to confirm proper venting before