Preparing The Operator - Chamberlain LiftMaster Professional BG770 Installation And Maintenance Manual

10
Preparing the Installation

Preparing the Operator

CAUTION
Never open electrical cabinet cover unless power is off. Electrical shock and serious injury could
result.
1 Remove the wood base from the unit and discard.
2 Locate the keys for the access panel (taped to the arm mounting flange) and remove.
3 Open the side access panel and check the position of the power ON/OFF switch.
4 Open the cover of the electrical cabinet and be sure that the AUTO/MANUAL switch is in the
"AUTO" position.
5 OPTIONAL CONTROL EQUIPMENT: If loop detectors, radio controls, or other control
equipment will be added at the site, do so now. Refer to the instructions in this manual for
installation of factory supplied optional open and/or hold open loop detectors, and for
connection of factory supplied optional radio controls (see Optional Accessories on page
19).
Doc 01-G0674
Rev D