Chamberlain HMJ, Owner'S Manual

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Output Shaft Key
Drive Sprocket
(2) Set Screws
3
PREPARATION
It is imperative that the wall or mounting surface
provide adequate support for the operator.
This surface must:
a. Be rigid to prevent play between operator and
door shaft.
b. Provide a level base.
c. Permit the operator to be fastened securely and
with the drive shaft parallel to the door shaft.
The safety and wear of the operator will be adversely
affected if any of the above requirements are not met.
For metal buildings, fasten 2" x 2" x 3/16" (or larger)
angle iron frames to the building purlins. Retain
5-1/2" between frames (Figure 1).
All MJ, MH, and HMJ series operators have dual output shafts and may be mounted on either the right (standard)
or left side of door, and in either a vertical (standard) or horizontal mounting position. If you need to move the drive
sprocket, loosen BOTH set screws, remove the sprocket and key, and place on the opposite side of the drive shaft.
Be sure to tighten BOTH set screws securely
Hand Chain Handing
For MH and HMJ models with manual hoist hand chain systems, the handing of the operator must be determined
at the time of order. The handing is indicated by last letter of the model name (R or L).
The hand chain wheel
can not be switched on site.
If your installation causes the hand chain to hang in the door opening, hook the
chain off to the side near the top of the door jamb.
IMPORTANT SAFETY NOTES
To prevent possible SERIOUS INJURY or DEATH:
• DO NOT connect electric power until instructed to do so.
• If the door lock needs to remain functional, install an interlock
switch.
• ALWAYS call a trained professional door serviceman if door
binds, sticks or is out of balance. An unbalanced door may not
reverse when required.
• NEVER try to loosen, move or adjust doors, door springs,
cables, pulleys, brackets or their hardware, ALL of which are
under EXTREME tension and can cause SERIOUS PERSONAL
INJURY.
• Disable ALL locks and remove ALL ropes connected to door
BEFORE installing and operating door operator to avoid
entanglement.
WARNING
CAUTION
WARNING
WARNING
5-1/2" (13.97 cm)
Shaft Support Bracket
with Bearing (Not Provided)
Door Sprocket