Chamberlain LIFTMASTER SL920 - Manual (Page 14)

14
Electrical Continued...
 If the gate operator is already factory
equipped with battery run, only the Right/Left
Side switch and the Mode switch need to be
set. The Right/Left switch simply needs to be
set in the same position as the Right/Left
switch on the main control board. (See page
17 for correctly setting the Right/Left switch
on the control board) The Mode switch can be
set in either the Mode 1 or Mode 2 position.
This choice between Mode 1 or Mode 2
depends on how the installer or end user
would like the gate to behave when power is
lost.
 Mode 1: Gate will continue to
operate when power is lost. When battery
power gets low, the gate will open and stay
open until power is restored. (Fail Secure)
 Mode 2: Gate will open immediately
when power is lost and remain open until
power is restored. (Fail Safe)
 If the gate operator did not come from
the factory equipped with battery run, field
installation of battery run is very simple. The
illustration at left shows additional wiring
required for battery run that is not part of the
standard wiring.
 First turn power off to the gate
operator.
 Disconnect the brown and red wires
from terminals 13 and 14 and insulate the
ends of the wires.
 Secure the charger board to the main
control board by attaching to the 14 screw
terminals on the left side of the control board.
 Connect a green wire from terminal 2
to terminal 15 of the control board.
 Attach an orange wire from terminal
D of the charger board to terminal 18 of the
main control board.
 Finally, attach a red wire from
terminal A to battery positive and a black wire
from terminal B to battery negative.
BATTERY BACK-UP
BATTERY BACK-UP