LiftMaster LMRRUL Manuel D'instructions page 4

Alignment
Reconnect power to the operator.
1. Align the sensor. The red LED indicates a misaligned or blocked sensor. The blue LED indicates signal
strength. Slow blinking indicates weak signal. Fast blinking indicates stronger signal. Solid blue LED
indicates optimal alignment.
2. When the sensor is optimally aligned, tighten the sensor bracket screws to secure the sensor in place
(about 24in-lb of torque). For extra security, tighten with the set screw until it grips the sensor.
3. Place the wire cover onto the sensor bracket. Make sure the tabs on the wire cover slide into the slots on
the top of the sensor bracket. Secure the wire cover with 8-32x3/8" screws. Wire cover is NOT intended for
use with conduit installations.
Test
Test ALL installed sensors for proper operation. Place
an obstruction in the sensor beam path and run the
operator. The gate will stop and reverse. If the gate
does not stop and reverse, refer to Troubleshooting
below. Perform the test with the obstruction in three
locations:
1
3
•
•
•
2
Halfway between the refl ector and sensor
Near the sensor
Near the refl ector
Red LED indicates
misaligned or
blocked sensor
Blue LED
Solid blue indicates
optimal alignment
Sensor bracket
screw
Set screw