Chamberlain Merlin MJ3800 Installation And Operating Instructions Manual page 12

TROUBLESHOOTING THE SAFETY
REVERSING SENSORS
1. If the sending eye indicator LEDs are both flashing
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 opener connections.
• Incorrect wiring between safety reversing 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 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
and the LED indicator light will flash 10 times. See
page 21.
To Cable Tension Monitor
To Power
Door Lock
com
no
To Door Control
dry contact
Quick-Connect Terminals
Opener
Connect Wire to
Quick-Connect
Te rminals
Sensor
Connections
WHT/BLK
WHT
MAX height
100mm (4")
MIN height
50mm (2")
MOUNTING AND WIRING THE SAFETY
REVERSING SENSORS
• Run the wires from both safety reversing sensors to the
opener. Use insulated staples to secure wire to wall and
ceiling.
• Strip 11mm (7/16") of insulation from each set of wires.
Separate white and white/black wires sufficiently to
connect to the opener quick-connect terminals: white to
white and white/black to grey (Figure 6 page 11).
Bell Wire
Power Door Lock
Invisible Light Beam
Safety Reversing Sensor
S ensor Protection Area
12
Bell Wire
Safety Reversing Sensor
Sensor