112032 Linear/Allstar Limit Switch SPDT Commercial Opener Garage Door Operator
the electrical enclosure and you'll find two Linear limit switches
mounted to the V bracket. There's the Reverse Cutout Switch (A) and the
Open Limit Switch (B). The limit switches are activated by the two
limits nuts on the threaded shaft as the operator open and closes the
door. When a limit nut nears the end of the shaft it activates a switch
which sends a signal back to the motor control board to stop the door.
Please reference your garage door opener manual for proper replacement
and adjustment of the limit switches.