LiftMaster SD Industrial-Duty Door Operator for Single and Bi-Parting Doors - Manual (Page 4)

OPERATOR ASSEMBLY
1. Layout the two pieces of track on the floor, parallel
to each other and install end idler shaft assembly
(see page 5).
2. Install track hangar brackets with 3/8” hardware
(see page 5). The number of hangars will vary with
the door width. The holes in the track for the hangars
are pre-punched and are generally about 5 feet apart.
3. Install chain take-up bolt on slider carriage with
two 3/8 hex nuts and lockwasher and slide the slider
carriage onto the track so that the take-up bolt will be
facing the powerhead (see page 5).
NOTE: For Bi-parting doors, slide secondary slider
carriage into track assembly first, so that this slider is
closest to the front idler.
4. Install one final track hangar on back of
powerhead. Remove the spacer bar which comes
assembled in the frame of the powerhead unit.
Position the track assembly on the motor unit and
reinstall the spacer within the rails, tightening the
bolts securely. For a right to open single-sliding door,
the powerhead should be mounted on the right hand
end of the track with the pulleys facing out.
The slide door operator should be pre-assembled as follows before installation:
Install two 3/8-16 x 1” hex bolts with lockwashers and
nuts though the remaining two mounting holes in the
power head (see page 5).
5. Attach the chain to the take-up bolt on the slider
carriage using the master link provided. Reel the
chain around the drive sprocket, up to the idler shaft
and then back to the hole on the front of the carriage.
6. Using the two 10-32 x 1-1/4 inch screws and
hardware provided, attach the chain to the front end
of the carriage (see figure 3). It may be necessary to
remove some links for proper tension. Tighten chain
by adjusting chain take-up bolt. A properly adjusted
chain will sag about 3” at the midpoint.
NOTE: Leave Bi-part slider carriage free at this time.
7. Bolt the angle mounting brackets to the track
hangers through the slots in the mounting brackets.
Use the 3/8-16 hex head bolts with flatwashers under
the heads and lockwashers and nuts under the track
hangers (see page 5). Do not tighten as the distance
from the wall to the track will have to be adjusted
later.
#10 FLATWASHER (4 PLACES)
SCREW, #10-32 x 1-1/4” SOCKET HEX (2 PLACES)
#10 LOCK WASHER
(2 PLACES)
#10 HEX NUT (2 PLACES)
SLIDER CARRIAGE ASSEMBLY
MASTER LINK
TAKE UP BOLT
FIGURE 3
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