Chamberlain ARM 1703EV Owner's Manual page 31

Standard Assembly (Door mounted inwards)
FIG. 14
Garage door with inward protruding lintel
1. To install the Chamberlain Door Arm at inward protruding lintel situations the door arm must be mounted in a
different way.
275 mm
240 - 275 mm
4. Take the curved door arm supplied with the Garage Door Opener and fit all as shown together. If you disconnect
the trolley you can move it easily in any position for the installation. Use M8 screws with lock nuts (not supplied).
5. Tighten the screws fully and back them off again 1/2 turn.
Open the garage door slowly and carefully by hand. Watch the movement of the door arm. If the Chamberlain Door
Arm hits the rail before the garage door is fully open, the angle of the arms must change. Close the garage door
and use another hole to change the angle of the system. Try again until the Chamberlain Door Arm does not hit the
rail anymore. In some cases raising the operator head is quicker.
2. Cut down the door arm supplied with your garage door operner (275mm).
3. Mount the cut down door arm to the trolley as shown. Do not use the slotted arm
supplied with the Chamberlain Door Arm.
FIG. 15