Position The Cable Tension Monitor (Required) - Chamberlain RJO20C Manual

Installation
(continued)
5
Install Power Door Lock
1. Pull down on the manual release to
disengage the door and open the
door manually.
2. Clean track surface, and attach
lock template to the track.
3. Drill holes as marked on the
template. You may find it useful to
pre-drill the holes with a smaller
bit before proceeding to larger
sizes.
4. Fasten power door lock to the
outside of the garage door track
with 1/4"-20x1/2" screws provided.
5. Run wire up wall to garage door
opener. Use insulated staples to
secure wire in several places.
6. Insert wire through the bottom of
the garage door opener and plug
the connector into the garage door
opener.
6

Position the Cable Tension Monitor (Required)

The cable tension monitor detects any slack in the garage
door cables. When slack is detected, the garage door
opener stops the door from closing, and reverses the
door to stay open. The cable tension monitor MUST be
connected and properly installed BEFORE the garage door
opener will move in the down direction.
The cable tension monitor must be installed on the
same side as the garage door opener. Factory default is
configured for left-side installation.
To watch a video, go to https://tinyurl.com/yadaxgzk
1. Determine if the cable tension monitor will be installed
on the left or right side of the door.
2. For left-side installation, skip to Step 3. For right-side
installation ONLY, remove the c-clip from the roller shaft,
move the roller to the other side, and reinstall the c-clip.
3. Make sure the door cable is approximately 3/4" (19 mm)
from the mounting surface.
4. Position the cable tension monitor 2" to 6" (5-15 cm)
from the drum, and over a wood support surface.
- Shim or add wood block if needed. The cable tension
monitor MUST be flush with the mounting surface.
- Cable tension monitor roller must be free from
obstructions.
NOTE: No obstructions should exist that prevent the cable
tension monitor from closing completely when slack is
detected.
1
2
3
13
YOU WILL NEED
Screw
1/4"-20x1/2" (2)
5
4
Approx. 3"
(7.6 cm)
Drum
6
2" to 6"
(5-15 cm)
Cable tension
monitor
Approx. 3/4"
(19 mm)
shim if
needed