Air pressure is lead via a hose or pipe to a diaphragm contact. This contact converts the positive or negative pressure into an electrical contact and pulse.
Molded enclosure
Applications: commercial sectional doors rolling doors and mass transit
Works on doors up to 60ft
Can be used with standard pneumatic hose and Miller Edge extrusion
Die cast metal enclosure with BEST cylinder (construction core included)
OPEN/CLOSE spring return to center (OFF) key removable in center position only. Should only be used on operators wired for constant pressure to open and close (all LiftMaster industrial operators with type D control wiring).
May be used in two different ways: as an OPEN only control (all LiftMaster operators) or as an OPEN/CLOSE control (only LiftMaster operators with types B2 and S2 control wiring).
In the latter case pulling the cord will open a fully closed door close a fully opened door and reverse a closing door.
Pulling the cord whlie the door is opening will either have no effect (type B2 wiring) or will stop the door (Solid State Logic Control Board).