The LiftMaster 50-103 Interior Air Switch (SPDT) is a pneumatic actuation switch designed for interior control of LiftMaster commercial door and gate operators. It converts an air pulse from a compatible air bulb or foot pedal into an electrical contact, allowing users to trigger door functions without placing live electrical components in wet or high-moisture zones. As a single-pole, double-throw device, it provides common, normally open, and normally closed contact options for flexible integration with control terminals on supported LiftMaster operators. This makes it a practical replacement part or upgrade for facilities such as car washes, service bays, and industrial shops that need reliable, hands-free or remote-push operation using air tubing.
Installation typically involves mounting the switch in a dry interior location near the operator or control panel, connecting the air tubing to the switch inlet, and wiring the SPDT contacts to the appropriate control inputs per the operator manual. For safety, always disconnect power before wiring and verify compatibility with the specific LiftMaster controller and control logic. The interior air switch design helps isolate electrical components from damp environments, supporting dependable performance in residential/commercial applications where pneumatic door control is preferred.