Chamberlain 1145-1/3HP - Manual (Page 8)

ASSEMBLY STEP 1
Attach T-Rail To Opener
TO AVOID INSTALLATION DIFFICULTIES,
DO NOT RUN OPENER UNTIL YOU ARE
INSTRUCTED TO DO SO.
USE ONLY THOSE SCREWS MOUNTED IN
TOP OF OPENER. FAILURE TO DO SO
WILL CAUSE SERIOUS DAMAGE TO THE
DOOR OPENER.
PROCEDURE: remove the two washered screws mounted
in top of opener. Position T-Rail at a 45 degree angle to
opener so one hole in T-rail and opener line up. Thread one
of the washered screws part way in.
CAUTION: USE ONLY THESE SCREWS! Use of any
other screws will cause serious damage to door
opener.
Align T-rail and styrofoam over opener sprocket. Cut tape
from T-rail, chain and styrofoam.
REMOVE STYROFOAM. Proceed to Step 2.
ASSEMBLY STEP 2
Attach Chain to Sprocket
PROCEDURE: Position chain over opener sprocket. If
necessary, loosen inner nut on trolley to obtain more
chain slack. Insert second washered screw.
CAUTION: Use only the screw previously removed
from opener
Tighten both screws securely through the T-rail into
opener as shown.
Insert back tab of sprocket cover in slot; then bend the
cover forward and insert front tab in slot provided on
mounting Plate.
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