Operator Mounting
Wall Mount: The operator should generally be installed below
the door shaft, and as close to the door as possible.
Bracket Shelf Mounting: The operator may be mounted either
above or below the door shaft.
NOTE: The optimum distance between the door shaft and
operator drive shaft is between 12" - 15".
Place door sprocket on the door shaft. Do not insert the key at
this time.
Place drive sprocket on the appropriate side of the operator. Do
not insert the key or set screw at this time.
Wrap chain drive around door sprocket and join roller chain
ends together with master link.
Raise operator to approximate mounting position and position
chain over operator sprocket.
Raise or lower operator until the chain is taut (not tight). Make
sure the operator output shaft is parallel to door shaft and
sprockets are aligned. When in position, secure the operator to
wall or mounting bracket.
Align sprockets, insert key into keyway, and secure.
Place hand chain around hand chain wheel (if provided).
Run the power wires through the power wiring conduit hole in
the electrical box enclosure. Connect the power to the operator.
Connect the earth ground to the ground screw in the electrical
box enclosure. Follow ALL local electrical codes.
Run control wires through the control wiring conduit hole in the
electrical box enclosure. Follow ALL local electrical codes.
Adjust the limit switches to open and close door properly. Make
sure the limit nuts are positioned between the limit switches
before proceeding with adjustments.
Remove cotter pin from nut on the clutch shaft. Back off clutch
nut until there is very little tension on the clutch spring. Tighten
clutch nut gradually until there is just enough tension to permit
the operator to move the door smoothly but to allow the clutch
to slip if the door is obstructed. Reinstall cotter pin when
finished.
Troubleshooting instructions inside cover of operator.
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IMPORTANT: This QuickStart is intended to highlight a typical installation. These instructions are not intended to be comprehensive. Because each application is unique, it is the responsibility of
the purchaser, designer, installer and end user to ensure that the total door system is safe for its intended use. Please consult the manual and/or a qualified technician for further information.
NOTE: Intended for Professional Installation Only. Visit www.LiftMaster.com to locate a professional installing dealer in your area.
A SAFETY DEVICE IS HIGHLY RECOMMENDED
Align Sprockets
7
OPTIONAL
Mounting Bracket
P/N 08-9098
Be sure door sprocket is properly
aligned with drive before securing to
the shaft.
Chain Retaining Bracket
(4' above floor)
Optimum Distance
12-15"
Optimum Distance
12-15"
Right Hand Wall Mounted Operator
1a Bracket Shelf Mounted Operator
1b MODEL MH
These operators are equipped with a manual hoist. An electrical interlock will disable the
electrical controls when the hoist is used. To operate the hoist
. Turn off power to the operator
BEFORE manually operating your door.
Pull the disconnect chain (sash chain) to engage the hoist mechanism. The disconnect
chain may be locked in position by slipping the end through the keyhole of the chain
retaining bracket mounted on the wall.
Operate the door in the desired direction by pulling on one side or the other of the
continuous loop hoist chain.
The disconnect chain must be released from the chain retaining bracket before the door
will operate again electrically.
MODEL MJ
This operator has a floor level disconnect chain to disconnect the door from the door
operator.
To disengage, pull the chain and secure in the disengaged position by slipping the end
through the keyhole bracket mounted on the wall. Or if emergency egress device is used,
pull handle to disengage operator from door.
The door may now be pushed up or pulled down manually.
Release the disconnect chain or reset the emergency egress device to operate the
door again electronically.
MODEL MHS
This operator includes two methods of manual operation:
A disconnect sash chain for push-up/pull-down operation. Refer to Model MJ
instructions above.
A hoist engagement sash chain for manual hoist operation. This chain can be found on the
clutch side of the operator. Refer to Model MH instructions above.
When operator is disconnected by the manual operation chain, hoist and electrical operation
will not function.
Manual Operation
QuickStartmodel MJ/MH/MHS
Medium Duty Logic
Keyhole Bracket
Manual Disconnect
Electrical Interlock with Hoist
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Turn off power to the operator
BEFORE manually operating your door.
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