Installation; Post Mounting - Chamberlain LiftMaster Professional SW420 Installation Manual

POST MOUNTING

1. Locate and anchor two posts made of 3" (7.6 cm) outer
diameter heavy walled pipe. Posts should be parallel and
square to the gate.
IMPORTANT NOTE: The distance between mounting posts and
the relative location of the operator to the gate and fence is
critical.
2. Locate electrical conduit, as required, prior to pouring
concrete.
3. Locate post mount holes on each end of the cabinet. There are
(3) sets of holes vertically.
The preferred method of post mounting is to use the (2) sets of
holes nearest to the rear side of the cabinet. Knock out the post
mount holes that have been selected.
NOTE: The preferred method of post mounting is to use the (2)
sets of holes nearest to the rear side of the cabinet. If mentioned
holes are used, the upper rear holes are larger than the other
holes. This is because a special nut is required for the U-bolt in
these holes due to an inaccessibility of tools inside the cabinet in
the area of these holes.
4. Insert the U-bolt nut through the cabinet wall from the inside
and onto the leg of the U-bolt. This nut can be tightened with a
wrench from outside the cabinet. A special tool is provided for
this purpose.
Figure 2
3" U-bolt
(4 required)
I N S T A L L A T I O N
Use tool provided to insert
special nut in rear holes.
Power and control wiring should be
run in separate conduit
Figure 1
Pivot
Gate
5-3/8"
11"
Pivot
Gate
18-1/4"
Perpendicular Mount
Rear of cabinet
Special nut
9
Fence Line
28"
21-1/4"
3"
3" Pipe
18-1/4"
Parallel Mount
Fence Line
17-3/8"
16"
21-1/4"