Mechanical Disconnect - Chamberlain LiftMaster Professional SW420 Installation Manual

MECHANICAL DISCONNECT

The operator can be disconnected from the gate, so the gate can
be manually opened or closed. Disconnect the control arm from
the drive hub by removing the hairpin cotter and then the clevis
pin and allowing the manual release pin to drop down through the
hub. The arm should now be free and the gate can be opened and
closed normally.
Figure 1
I N S T A L L A T I O N
NOTE: If desired, a padlock can be used in place of the clevis pin
to hold the manual release pin in place.
Clevis Pin
Hairpin Cotter
13
Control Arm
Drive Hub
Release Pin