Chamberlain 8100M Manuale Utente

Invisible Light Beam

Protection Area

Sensor

Sensor

Connect Wire to

Opener Terminals

The Chamberlain Group, Inc.
Attaching Sensor to "C" Wrap and Wires to Operator
Liftmaster Synchro Drive
5/19/92

Bell Wire

Bell Wire

Finished

Ceiling

OPENER TERMINAL SCREWS

Sensor

Connections

Door Control

Connections

(dotted line)

• Center each sensor unit in a "C" wrap with lenses

pointing toward each other across the door (see
Figure 6). 

• Secure sensors with the hardware shown in 

Figure 7. Finger tighten the wing nut on the
receiving eye to allow for final adjustment.
Securely tighten the 

sending eye wing nut.

• Run the wires from both sensors to the opener.

Use insulated staples to secure the wire to the 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.

• Plug in the opener. Green indicator lights in both

the sending and receiving eyes will 

glow steadily if

wiring connections and alignment are correct.

The 

sending eye indicator light will glow regardless

of alignment or obstruction. If the indicator light is
off, dim, or flickering in the 

receiving eye (and the

invisible light beam path is not obstructed),
alignment is required.

• Loosen the 

sending eye wing nut and re-adjust,

aiming directly at the receiving eye. Lock in place.

• Loosen the 

receiving eye wing nut and adjust

sensor vertically and/or horizontally until it receives
the sender’s beam. When the green indicator light
glows steadily, tighten the wing nut.

23

1/4-20 x 1-1/2"

Hex Bolt

"C" Wrap

Sensor

with Wire

Wing

Nut

Indicator 

Light

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 under staples or at screw terminal
connections.

• Incorrect wiring between sensors and opener.
• An open wire (wire break).

2. If the sending eye indicator light 

glows steadily but

the receiving eye indicator light doesn't:
• Check alignment.
• Check for an open 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 will not close.
The opener lights will flash 10 times. (If bulbs are not
installed, 10 clicks are audible.) See page 21.

1/4-20x1-1/2"

Hex Bolt

Wing Nut