Craftsman 139.53975SRT - Manual (Page 23)

Mounting and Wiring the Safety Sensors
• Slide a 1/4"-20x1/2" carriage bolt head into the slot
on both sensors. 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. See Figure 5.
• Finger tighten the sensor wing nuts.
• Run the wires from both sensors to the opener. Use
insulated staples to secure wire to wall and ceiling.
• Strip 1/4" of insulation from each set of wires.
Separate white and white/black wires sufficiently to
connect to the opener terminal screws: white to 2
and white/black to 3.
Aligning the Safety Sensors
• Plug in the opener. The indicator lights in both the
sending and receiving eyes will glow sfead/7/if wiring
connections and alignment are correct.
The sending eye orange indicator light wilt glow
regardless of alignment or obstruction. If the green
indicator light in the receiving eye is off, dim, or
flickering (and the invisible light beam path is not
obstructed), alignment is required.
• Loosen the sending eye wing nut and readjust,
aiming directiy at the receiving eye. Lock in place.
• Loosen the receiving eye wing nut and adjust sensor
verticaily and/or horizontally until it receives the
sender's beam. When the green indicator light glows
steadily, tighten the wing nut.
Figure 5
Wing nut
1/4‘-20xt/2‘
Carriage bolt
Trouble Shooting the Safety Sensors
1. if the sending eye indicator light does not glow
steadily after installation, check for:
• Electric power to the opener.
• A short in the white or white/black wires. These can
occur at staples, or at screw terminal connections.
• Incorrect wiring between sensors and opener.
• A broken wire.
2. If the sending eye indicator light glows steadily but the
receiving eye indicator light doesn't:
• Check alignment.
• Check for a broken wire to the receiving eye.
3. If the receiving eye indicator light is dim, realign either
sensor.
NOTE: When the invisible beam path is obstructed or
misaligned while the door is closing, the door will
reverse. If the door is already open, it wiit not ctose. The
opener lights will flash 10 times. (If bulbs are not
installed, 10 clicks can be heard.) See page 21.
Figure 6
Bell Wire
' Sensor
Invisible Light Beam
Protection Area
Sensor
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