Dead Shaft Door Requirements - LiftMaster LJ8950W Manuel

Installation

Dead Shaft Door Requirements

For dead shaft door installations the door sprocket is attached to the door drum which
spins to move the door.
DRUM CONDITON
The door drum must not be bent or damaged. If bent, the drive chain may not align to the
sprocket and could derail the chain.
If the drum does not have mounting holes which align to the door sprocket, use the door
sprocket as a template to drill holes in the proper location.
SPRING CLEARANCE
The internal door springs must not interfere with the door sprocket installation. Inspect
for interference by sliding the door sprocket on the door shaft to the drum and aligning
the mounting holes. Sprocket mounting holes should not be obstructed by the door
spring for a minimum depth of 3" (7.6 cm). Some door manufacturers require the door to
be modified with an extra drum on the end of the door barrel to provide an unobstructed
platform for door sprocket installation.
DOOR CLEARANCE
The dead shaft door must not have more than a 2" (5 cm) space from the curtain edge to
the drum. The door operator comes with a selection of spacers that can be used together
to provide a maximum 3" (7.6 cm) of spacing.
MINIMUM SIDE CLEARANCE
A minimum of 11" (27.9 cm) clearance on the outside of the door guide is required for
outside mounting. A minimum of 3.75" (9.5 cm) clearance is required for inside mounting.
If the door brackets interfere with door operator installation, move the door brackets away
from the door assembly to provide room in the desired location.
Door
Shaft
Door
Bracket
11" (27.9 cm) Min. Clearance
Outside Mounting
3.75" (9.5 cm) Min. Clearance
2" (5 cm) Max Inset
2.5" (6.3 cm) Min.
Clearance
Inside Mounting
3" (7.6 cm)Bolt
Clearance
Drum
Door Guide
8
Remove existing door sprocket. You
MUST use the door sprocket provided in
order for the door operator to function
correctly.
Door Sprocket
Mounting Pattern
Use 3 holes 120˚ Apart
Spring