Chamberlain LiftMaster Security+ 3245CM Owner's Manual page 17

MOUNTING AND WIRING THE SAFETY REVERSING
SENSORS
Mounting:
• Slide a 1/4"-20x1/2" carriage bolt head into the slot
on each sensor. Use wing nuts to fasten sensors
to brackets, with lenses pointing toward each other
across the door. Be sure the lens is not obstructed by a
bracket extension (Figure 5).
• Finger tighten the wing nuts.
Option A - Installation Without Pre-Wiring:
• Run the bell wire from both sensors to the garage door
opener. Attach the wire to the wall and ceiling with the
staples (Figure 6).
Option B - Pre-Wired Installation:
If your garage already has wires installed for the safety
reversing sensors, follow the instructions below:
• Cut the end of the safety reversing sensor wire, making
sure there is enough wire to reach the pre-installed
wires from the wall (Figure 7).
• Separate the safety reversing sensor wires and strip
7/16" (11 mm) of insulation from each end. Choose
two of the pre-installed wires and strip 7/16" (11 mm)
of insulation from each end. Make sure that you choose
the same color pre-installed wires for each sensor
(Figure 8).
• Connect the pre-installed wires to the sensor wires with
wire nuts making sure the colors correspond for each
sensor (Figure 9).
Figure 5
Carriage Bolt
1/4"-20x1/2"
Figure 6
Figure 7
Figure 8
Safety Reversing
Sensor Wires
Figure 9
Safety Reversing
Sensor Wires
White
White/Black
17
Wing Nut
1/4"-20
Lens
7/16"
(11 mm)
Pre-Installed Wires
Not Provided
Pre-Installed Wires
7/16"
(11 mm)