Master/Second Wiring - Chamberlain LiftMaster SL930 User Manual

MASTER/SECOND WIRING

Connect 115 Volts AC to each SL930 gate operator. Connect the
four Master/Second wires from the master circuit board to the
second circuit board (Figure 7). Any operator can be used as
either a master or a second. Accessories can be connected to the
master or second operator.
Switch the Auto Close Timer switch to the OFF position on the
second circuit board. The Auto Close Timer switch on the master
circuit board may be switched either ON if the timer function will
be used or OFF if the timer function will not be used but the
second timer must always be switched OFF.
If the chain is wrapped around the sprockets in the same manner
on each operator (both chains under or both chains over the drive
sprocket), set the Right/Left Side Operation switch on the master
circuit board to be the opposite of the way it is set on the second
circuit board. If the chain wrapped around the drive sprocket on
the master operator is the opposite of the way it is wrapped
around on the second operator, then set the Right/Left Side
Operation switches the same on both operators. The Right/Left
Side operation switch is located on the circuit board. If the
operators are working backwards, the Right/Left Side Operation
switches on both operators must be switched. The simplest way
to know if the operators are working backwards is to turn the
Auto Close Timer switch on the master circuit board to ON and
see whether the timer works when the gate is open or closed. The
timer should work only when the gate is open. Another way to
know if the operators are working backwards is to try the gate
sensitivity by applying pressure against the gate while the gate is
opening or closing. If pressure is applied while the gate is
opening, it should stop. If pressure is applied while the gate is
closing, it should reverse and go open. If the gate responds to
pressure in a way that is opposite of this, then switch the Right/
Left Side Operation switch on both operators.
W I R I N G
Figure 7
MASTER
SECOND
18