LiftMaster 3240 3240 Manual - Page 13

MOUNTING AND WIRING THE SAFETY SENSORS • 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. Recommended Wire Routing 1. Using insulated staples, run the wires from both sensors to the rail at the door header (Figure 6). 2. Run the wires through wire clips at the top of the rails. NOTE: If your access door is near the garage door, you may choose to install the door control at this time and run the door control wire along the rail with the sensor wires. Wing Nut Carriage Bolt 1/4"-20x1/2" Lens HARDWARE SHOWN ACTUAL SIZE Carriage Bolt 1/4"-20x1/2" Wing Nut 1/4"-20 Staples Figure 6 Sensor Wire Wire Clips Bell Wire Rail Safety Reversing Sensor Invisible Light Beam Protection Area Safety Reversing Sensor 13