LiftMaster MGH Medium Duty Door Operator Owner’s Manual

: June 16, 2024
: LiftMaster

Table of Contents

MGH Medium Duty Door Operator
Product Information
Specifications
Carton Inventory
Operator Dimensions
MGJ
MGH
- Operator Specifications
- Product Usage Instructions
- Preparation
MGJ Opposite Handing Preparation
MGH Left Hand Mounting Preparations
- Installation
Mount the Operator
Manual Operation
Entrapment Protection Accessories (Optional)
- Adjustment
Limit Switch Adjustment
- Power Wiring & Ground Wiring
Power Wiring Connections
Ground Wiring Connections
- Control Wiring & Installation
Determine Wiring Type
Model MGJ
Special Control Wiring
Mounting Instructions
- Diagrams
Single Phase Schematic Diagram for MGJ/MGH
Three Phase Schematic Diagram for MGJ Only
- Maintenance
Maintenance Schedule
How to Order Repair Parts
- Repair Parts
- FAQ (Frequently Asked Questions)
Q: Is this product suitable for residential use?
- 2 in the electrical enclosure. The operator will require constant pressure on
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)

MGH Medium Duty Door Operator

Product Information

Specifications

Model: MGH & MGJ
Type: Medium Duty Door Operator
Warranty: 2 years
Serial #: Located on electrical box cover
Installation Date: Refer to the installation date
Wiring Type: Visit www.liftmaster.com

Carton Inventory

Before beginning your installation, check that all components
were provided:

Powerhead assembly
Owner’s manual and caution labels
Hardware box
3-button control station
Hoist hand chain (MGH Model only)
Door sprocket
Door/operator drive chain

Operator Dimensions

MGJ

Hanging Weight: 50-60 lbs.
Mounting Dimensions:
- Width: 7.50 in (19.05 cm)
- Height: 10.50 in (26.67 cm)
- Depth: 11.05 in (28.07 cm)

MGH

Hanging Weight: 70-80 lbs.
Mounting Dimensions:
- Width: 18.00 in (45.72 cm)
- Height: 11.25 in (28.58 cm)
- Depth: 2.99 in (7.59 cm)

Operator Specifications

Motor Type: Limited Duty
Horsepower:
- MGJ: 1/2 HP 1 or 3 Phase, 3/4 HP 1 Phase (only)
- MGH: 1/2 & 3/4 HP 1 Phase
Voltage:
- MGJ: 120V, 60Hz, 1Ph; 230V, 50 or 60Hz, 3Ph; 230V, 60Hz, 1Ph;
  380V, 50Hz, 3Ph; 460V, 60Hz, 3Ph
- MGH: 120V, 60Hz, 1Ph

Product Usage Instructions

Preparation

MGJ Opposite Handing Preparation

Follow the instructions provided in the manual for MGJ opposite
handing preparation.

MGH Left Hand Mounting Preparations

Refer to the manual for MGH left hand mounting preparations.

Installation

Mount the Operator

Follow the steps below to mount the operator:

Refer to the mounting dimensions for the specific model (MGJ or
MGH).
Ensure proper alignment and secure the operator to the mounting
surface using the provided hardware.

Manual Operation

To manually operate the door, follow these steps:

Locate the manual operation mechanism on the operator.
Engage the mechanism and operate the door manually as
needed.

Entrapment Protection Accessories (Optional)

If you have optional entrapment protection accessories, refer to
the manual for installation instructions.

Adjustment

Limit Switch Adjustment

To adjust the limit switches, follow these steps:

Refer to the manual for the specific adjustment procedure.
Make necessary adjustments to ensure proper door travel and
stopping positions.

Power Wiring & Ground Wiring

Power Wiring Connections

To make power wiring connections, follow these steps:

Refer to the wiring diagram in the manual for your specific
wiring type.
Connect the power wires according to the diagram and secure
them properly.

Ground Wiring Connections

To make ground wiring connections, follow these steps:

Refer to the wiring diagram in the manual for your specific
wiring type.
Connect the ground wires according to the diagram and ensure
proper grounding.

Control Wiring & Installation

Determine Wiring Type

Refer to the manual to determine the appropriate wiring type for
your installation.

Model MGJ

For model MGJ, follow the control wiring instructions provided
in the manual.

Special Control Wiring

If you have special control wiring requirements, refer to the
manual for detailed instructions.

Mounting Instructions

Follow the mounting instructions provided in the manual to
properly install the control station.

Diagrams

Single Phase Schematic Diagram for MGJ/MGH

Refer to the schematic diagram in the manual for the
single-phase operation of MGJ/MGH models.

Three Phase Schematic Diagram for MGJ Only

Refer to the schematic diagram in the manual for the three-phase
operation of MGJ model.

Maintenance

Maintenance Schedule

Follow the maintenance schedule provided in the manual to ensure
proper operation and longevity of the operator.

How to Order Repair Parts

If you need to order repair parts, refer to the manual for
instructions on how to place an order.

Repair Parts

Refer to the manual for warnings and important notes regarding
mechanical and electrical repairs.

FAQ (Frequently Asked Questions)

Q: Is this product suitable for residential use?

A: No, this product is not intended for residential use.

OWNER’S MANUAL
MODELS MGH & MGJ
MEDIUM DUTY DOOR OPERATOR

2 YEAR WARRANTY
Serial # (located on electrical box cover) Installation Date Wiring Type www.liftmaster.com

NOT FOR RESIDENTIAL USE
41B6

TABLE OF CONTENTS

CARTON INVENTORY
Carton Inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Operator Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Operator Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
PREPARATION
MGJ Opposite Handing Preparation . . . . . . . . . . . . . . . . . . . . . . 5 MGH Left Hand Mounting Preparations . . . . . . . . . . . . . . . . . . . 6
I N S TA L L AT I O N
Mount the Operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Entrapment Protection Accessories (Optional) . . . . . . . . . . . . . . 8
ADJUSTMENT
Limit Switch Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
POWER WIRING & GROUND WIRING
Power Wiring Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Ground Wiring Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
CONTROL WIRING & INSTALLATION
Determine Wiring Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Model MGJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Special Control Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Mounting Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

DIAGRAMS
Single Phase Schematic Diagram for MGJ/MGH . . . . . . . . . . . 12 Three Phase Schematic Diagram for MGJ Only . . . . . . . . . . . . 13
MAINTENANCE
Maintenance Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 How to Order Repair Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
REPAIR PARTS
MGH Illustrated Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Replacement Part Kits MGH . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 MGJ/MGH Electrical Box – Illustrated Parts . . . . . . . . . . . . . . . 18 Electrical Box – Models MGJ & MGH . . . . . . . . . . . . . . . . . . . . 19 Illustrated Parts – Model MGJ. . . . . . . . . . . . . . . . . . . . . . . . . . 20 Replacement Part Kits MGJ . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Operator Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-23 Control Connection Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . 24

WARNING
Mechanical
WARNING
Electrical
CAUTION
When you see these Safety Symbols and Signal Words on the following pages, they will alert you to the possibility of serious injury or death if you do not comply with the warnings that accompany them. The hazard may come from something mechanical or from electric shock. Read the warnings carefully. When you see this Signal Word on the following pages, it will alert you to the possibility of damage to your door and/or the door operator if you do not comply with the cautionary statements that accompany it. Read them carefully.

IMPORTANT NOTES:
· BEFORE attempting to install, operate or maintain the operator, you must read and fully understand this manual and follow all safety instructions.
· DO NOT attempt repair or service of your commercial door and gate operator unless you are an Authorized Service Technician.

2

CARTON INVENTORY
Before beginning your installation check that all components were provided.
DESCRIPTION POWERHEAD ASSEMBLY OWNER’S MANUAL AND CAUTION LABELS HARDWARE BOX 3-BUTTON CONTROL STATION HOIST HAND CHAIN (MGH Model only) DOOR SPROCKET DOOR/OPERATOR DRIVE CHAIN

OPERATOR DIMENSIONS

WEIGHTS AND DIMENSIONS – MGJ

HANGING WEIGHT:

50-60 LBS.

7.50″ (19.05 cm)

10.50″ (26.67 cm) 11.05″ (28.07 cm)

Mounting Dimensions
5.50″ (13.97 cm)

7.00″ (17.78 cm)
9.25″ (23.50 cm)

WEIGHTS AND DIMENSIONS – MGH

HANGING WEIGHT:

70-80 LBS.

18.00″ (45.72 cm)

11.25″ (28.58 cm)
2.99″ (7.59 cm)

11.00″ (27.94 cm)

3.00″ (7.62 cm)

4.75″ (12.07 cm)

13.28″ (33.73 cm)

.98″ (2.49 cm)

4.50″ (11.43 cm)
2.25″ (5.72 cm)

1.96″ (4.98 cm)

Mounting Dimensions

3

OPERATOR SPECIFICATIONS

MOTOR
TYPE: . . . . . . . . . . . . . . . . . . .Limited Duty
HORSEPOWER: . . . . . . . . . . .MGJ: 1/2 HP 1 or 3 Phase MGJ: 3/4 HP 1 Phase (only) MGH: 1/2 & 3/4Hp 1 Phase
VOLTAGE: . . . . . . . . . . . . . . . .MGJ: 120V, 60Hz, 1Ph 230V, 50 or 60Hz, 3Ph 230V, 60Hz, 1Ph 380V, 50Hz, 3Ph 460V, 60Hz, 3Ph MGH: 120V, 60Hz, 1Ph
CURRENT: See motor nameplate
The rate of operation shall not exceed 12 cycles of opening and closing per hour.

ELECTRICAL
TRANSFORMER:. . . . . . . . . . 24VAC CONTROL STATION:. . . . . . . NEMA 1 three button station.
OPEN/CLOSE/STOP WIRING TYPE: . . . . . . . . . . . MGH/MGJ: C2 (factory default), B2
optional
LIMIT ADJUST:. . . . . . . . . . . Linear driven, fully adjustable screw type cams. Adjustable to 18 feet.

MECHANICAL
DRIVE REDUCTION: . . . . . . . . . . . 45:1 Reduction (Heavy duty wormgear-in- oil-bath speed reducer)
OUTPUT SPROCKET: . . . . . . . . . . Size #41
OUTPUT SHAFT SPEED:. . . . . . . . MGJ: 1Ph, 23RPM 3Ph, 39RPM
. . . . . . . . . . . . . . . . . . . . . . . . . . . MGH: 1Ph, 23RPM
BEARINGS: . . . . . . . . . . . . . . . . . . Heavy duty wormgear-in-oilbath speed reducer.
DUTY: . . . . . . . . . . . . . . . . . . . . . . 12 Cycles per Hour max 50 Cycles per Day max
DOOR SPEED:. . . . . . . . . . . . . . . . 9″ per second, typical, depending on door.
MAX. DOOR HEIGHT: . . . . . . . . . . 1/2 HP = 14′ 3/4 HP = 18′

SAFETY
DISCONNECT:. . . . . . . . . . . . . . . . . . . . Floor level disconnect for emergency manual door operation.
REVERSING EDGE (Optional): . . . . . . . Electric or pneumatic sensing device attached to the bottom edge of door
A REVERSING EDGE IS STRONGLY RECOMMENDED FOR ALL COMMERCIAL OPERATOR INSTALLATIONS. REQUIRED WHEN THE 3 BUTTON CONTROL STATION IS OUT OF SIGHT OF DOOR OR ANY OTHER CONTROL (AUTOMATIC OR MANUAL) IS USED.

4

PREPARATION

Shipped from the factory for either left hand or right hand mounting. Refer to the last digit in the model number for handing of your unit. If necessary, the operators may also be field modified to accommodate opposite handing.
MGJ OPPOSITE HANDING PREPARATIONS
REMOVE DISCONNECT ASSEMBLY COMPONENTS
Remove the master link from the limit chain, remove the chain and set it aside. Remove the two e-rings securing the sprocket on the gear reducer shaft. Remove the screws securing the yoke to the disconnect shaft, set the yoke aside.
Remove the three cotter pins from the disconnect shaft. Do not discard the pins. Slide the disconnect shaft out of the support bracket. The release lever will now be free inside the motor frame. Remove the release lever and sash chain from the motor frame. Slide the disconnect hub, compression spring, and flatwasher from the end of the gear reducer shaft. Remove the disconnect support bracket by first removing the two gear reducer housing screws. Replace the screws in the gear reducer and firmly tighten.
RE-ASSEMBLE DISCONNECT ASSEMBLY
Remove the two screws on the opposite side of the gear reducer and mount the disconnect support bracket with the notched side facing the motor. For the remainder of the installation, follow the steps outlined above in reverse order, referring to the illustration as necessary.

WARNING
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.
REMOVE LIMIT SWITCH SHAFT ASSEMBLY Remove limit chain. Remove the e-ring and washers from the side away from the limit chain sprocket. Remove limit shaft. The limit adjust nuts will need to be unscrewed while removing shaft. To reassemble follow the above steps in reverse order.

Keys Spring
Disc Hub

Sprocket E-Ring
Bracket Yoke

Shaft Disc Lever

5

PREPARATION
MGH LEFT HAND MOUNTING PREPARATIONS
The operator may be mounted on either the right (standard) or left side of door, and in either a vertical (standard) or horizontal mounting position. Refer to the steps below if you require the hand chain and/or disconnect chain to be on the opposite side of the operator; or if the operator is being mounted in a horizontal position.
HAND CHAIN RIGHT/LEFT CONVERSION 1. Remove snap ring from end of shaft on the hoist side. 2. Remove the washers, chain guide and chain wheel. 3. Remove drive pin from shaft and relocate to the opposite
side. 4. Install chain wheel, chain guide, washers and snap ring. DISCONNECT LEVER RIGHT/LEFT CONVERSION 1. Remove cotterpins on the ends of the disconnect shaft
(square shaft). 2. Move the disconnect lever arm and the washer to the
opposite sides. 3. Replace the cotterpins. HORIZONTAL MOUNTING CONVERSION 1. Remove cotterpin on the ends of the disconnect shaft
(square shaft). 2. Remove lever and turn 90 degrees so that the lever is pointing
away from the motor. The lever will be directly under the hoist shaft. 3. Replace cotterpin.
Disconnect Lever
Chain GuideHand

Cotterpin
Cutout for Roll Pin (typical both sides)
6

Hand Chain Wheel

I N S TA L L AT I O N

IMPORTANT NOTE: Before your operator is installed, be sure the door has been properly aligned and is working smoothly. The operator may be wall mounted or mounted on a bracket or shelf. If necessary, refer to the preparation on page 5. Refer to the illustration and instructions below that suits your application.

FIGURE 1

MOUNT THE OPERATOR
1. Wall Mount: The operator should generally be installed below the door shaft, and as close to the door as possible (Figure1). Bracket Shelf Mounting: The operator may be mounted either above or below the door shaft (Figure 2).
IMPORTANT: The shelf or bracket must provide adequate support, prevent play between operator and door shaft, and permit operator to be fastened securely and with the drive shaft parallel to the door shaft.
NOTE: The optimum distance between the door shaft and operator drive shaft is between 12-15″ (30.5-38.1 cm).
2. Place door sprocket on the door shaft. Do not insert the key at this time.
3. Place drive sprocket on the appropriate side of the operator. Do not insert the key at this time.
4. Wrap drive chain around door sprocket and join roller chain ends together with master link.
5. Raise operator to approximate mounting position and position chain over operator sprocket.
6. 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.
7. Align sprockets and secure (Figure 3).
8. Install Hand Chain (Model MGH only) Place hand chain around hand chain wheel. Be sure to pass it through both openings in the chain guide. Remove enough links so chain hangs approximately 2′ (.61 m) above the floor.
9. Mount Chain Keeper / Keyhole Bracket Using suitable hardware mount the chain keeper approximately 4′ (1.22 m) above the floor, near the free hanging chain. Remove disconnect sash chain from bag and place the end through the keyhole in the chain keeper. Remove excess links if necessary.

FIGURE 2
FIGURE 3
Be sure door sprocket is properly aligned with drive before securing to the shaft.

Typical Right Hand Wall Mounted Operator
OPTIONAL Mounting Bracket P/N 089098

7

I N S TA L L AT I O N

MANUAL OPERATION
This operator is equipped with a floor level disconnect chain to allow for manual operation of the door in case of emergency or power failure.
MODEL MGJ 1. To disengage, pull the sash 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.

WARNING
To prevent possible SERIOUS INJURY from a moving chain, DISCONNECT electric power to the operator BEFORE manually operating your door.
MGJ

2. The door may now be pushed up or pulled down manually or if equipped with manual hand chain hoist (model MGH only), door can be raised or lowered with hand chain. Release the disconnect chain to operate the door again electrically.
MODEL MGH
1. Pull the disconnect chain (small chain) to engage the interlock to disable the controls. The disconnect chain may be locked in position by slipping the end through the keyhole of the chain keeper mounted on the wall.

Keyhole Bracket

2. Operate the door in the desired direction by pulling on one side or the other of the continuous loop hoist chain (large chain).
3. The disconnect chain must be released from the chain keeper before the door will operate again electrically.

MGH

Chain Keeper (with pad locking provisions)

ENTRAPMENT PROTECTION ACCESSORIES (OPTIONAL)

WARNING

SENSING EDGES
All types of sensing edges with an isolated normally open (N.O.) output are compatible with your operator. This includes pneumatic and electric edges. If your door does not have a bottom sensing edge and you wish to purchase one, contact the supplier of your operator.

To reduce the risk of SEVERE INJURY or DEATH, ALWAYS install reversing sensors when the 3-button control station is out of sight of door or ANY other control (automatic or manual) is used. Reversing devices are recommended for ALL installations.

If not pre-installed by the door manufacturer, mount the sensing edge on the door according to the instructions provided with the edge. The sensing edge may be electrically connected by either coiled cord or take-up reel. Refer to the steps below.
IMPORTANT NOTES:
a. Proceed with Limit Switch Adjustments described below before making any sensing edge wiring connections to operator.
b. Electrician must hard wire the junction box to the operator electrical box in accordance with local codes.

TAKE-UP REEL Take-up reel should be installed 12″ (30.48 cm) above the top of the door.
COIL CORD Connect operator end of coil cord to junction box (not provided) fastened to the wall approximately halfway up the door opening.

8

ADJUSTMENT

LIMIT SWITCH ADJUSTMENT
NOTE: Make sure the limit nuts are positioned between the limit switches before proceeding with adjustments. 1. Depress retaining plate to allow nut to spin freely. After
adjustment, release plate and move nut back and forth to ensure it is fully seated in slot. 2. To increase door travel, spin nut away from limit switch. To decrease door travel, spin limit nut toward limit switch. 3. Adjust open limit nut so that door will stop in open position with the bottom of the door even with top of door opening. 4. Repeat steps 1 and 2 for close cycle. Adjust close limit nut so that the limit switch is engaged as door fully seats at the floor.

WARNING
To avoid SERIOUS PERSONAL INJURY or DEATH from electrocution, disconnect electric power BEFORE manually moving limit nuts.

CLOSE Limit Switch

OPEN Limit Switch Actuator

SAFETY (Aux. Close) Limit Switch

Retaining Plate (Aux. Open) Limit Switch

9

POWER WIRING & GROUND WIRING
WARNING

To reduce the risk of SEVERE INJURY or DEATH:
· ANY maintenance to the operator or in the area near the operator MUST NOT be performed until disconnecting the electrical power and locking-out the power via the operator power switch. Upon completion of maintenance the area MUST be cleared and secured, at that time the unit may be returned to service.
· Disconnect power at the fuse box BEFORE proceeding. Operator MUST be properly grounded and connected in accordance with local electrical codes. The operator should be on a separate fused line of adequate capacity.

· ALL electrical connections MUST be made by a qualified individual.
· DO NOT install ANY wiring or attempt to run the operator without consulting the wiring diagram. We recommend that you install an optional reversing edge BEFORE proceeding with the control station installation.
· ALL power wiring should be on a dedicated circuit and well protected. The location of the power disconnect should be visible and clearly labeled.
· ALL power and control wiring MUST be run in separate conduit.

POWER WIRING CONNECTIONS
1. Connect power wires coming from the main to the captive terminal block in the electrical box enclosure marked with the label. All power and control wiring must be run in separate conduit in accordance with local electrical codes.
2. Be sure to run all power wires through the conduit hole in the electrical box enclosure marked with the label shown below.
NOTE: Must use #14 AWG or thicker wire for power wiring.
ON THREE PHASE MACHINES ONLY: Incorrect phasing of the power supply will cause the motor to rotate in the wrong direction. To change motor rotation, exchange incoming power leads L1 and L2.
GROUND WIRING CONNECTIONS
1. Connect earth ground to the chassis ground screw in the electrical box enclosure.
2. Use same conduit entry into the electrical box as the power wiring.
IMPORTANT NOTE: This unit must be properly grounded. Failure to properly ground this unit could result in electric shock and serious injury.

Single Phase Power Wiring
1 2 3 4 7 10 11 12 L1 L2

Hot

Gnd

Neutral

Three Phase Power Wiring

1 2 3 4 7 10 11 12 L1 L2 L3

Phase 3

Phase 1

Gnd

Phase 2

10

CONTROL WIRING & INSTALLATION

WARNING

To reduce the risk of SEVERE INJURY or DEATH:
· ANY maintenance to the operator or in the area near the operator MUST NOT be performed until disconnecting the electrical power and locking-out the power via the operator power switch. Upon completion of maintenance the area MUST be cleared and secured, at that time the unit may be returned to service.
· Disconnect power at the fuse box BEFORE proceeding. Operator MUST be properly grounded and connected in accordance with local electrical codes. The operator should be on a separate fused line of adequate capacity.

· ALL electrical connections MUST be made by a qualified individual.
· DO NOT install ANY wiring or attempt to run the operator without consulting the wiring diagram. We recommend that you install an optional reversing edge BEFORE proceeding with the control station installation.
· ALL power wiring should be on a dedicated circuit and well protected. The location of the power disconnect should be visible and clearly labeled.
· ALL power and control wiring MUST be run in separate conduit.

DETERMINE WIRING TYPE
Refer to the wiring diagram located on the inside cover the electrical box to determine the type of control wiring.
STANDARD C2 OR B2 WIRING
Operators are shipped from the factory with jumper set for C2 wiring, which requires constant pressure on button to close the door. If momentary contact in close direction is desired (B2 wiring) you must include an entrapment protection device. See close control jumper setting below.
Constant pressure on close (C2 wiring) Red jumper wire was placed on terminal

2 in the electrical enclosure. The operator will require constant pressure on

close control in order to keep door moving in the close direction.
Momentary contact on close (B2 wiring) Move red jumper wire from terminal #2 to terminal #3. The operator will require only momentary contact to close the door.
SPECIAL CONTROL WIRING
If your operator was shipped from the factory with non-standard control wiring or with optional accessories that require additional instructions, refer to the wiring diagram(s) indicated in the special control wiring data box. When a replacement wiring diagram is present, wiring diagrams in this manual will not apply. Refer only to the replacement wiring diagram for all connections.
IMPORTANT NOTE: If your wiring diagram is missing, or you are unsure of the wiring type for your operator, contact the customer service department @ 1-800-528-2806.
MOUNTING INSTRUCTIONS
All operators are supplied with some type of control station. Generally a 3-button station (OPEN/CLOSE/STOP) is provided. A two-position key switch or control station (OPEN/CLOSE) may be added or substituted when requested at the time of order. 1. Mount WARNING NOTICE beside or below the control station. 2. Mount control station(s) within line of sight of door(s).

WARNING
TO PREVENT ENTRAPMENT DO NOT START DOOR DOWNWARD
UNLESS DOORWAY IS CLEAR
Control Station
4′ Approximate

11

SINGLE PHASE SCHEMATIC DIAGRAM FOR MGJ/MGH

L2

BK

CLOSE-B

BL

Y

C N.O.

W

RES.

OPEN-A
R

Y

CAPACITOR

R

MOTOR * O/L BK L1
BR

WIRE NUT

PR1.

3

STOP

4

MOVE JUMPER WIRE TO TERMINAL #2 FOR MOMENTARY CONTACT ON CLOSE

Y (WHEN PRESENT)
HAND CHAIN INTERLOCK SW.
R

10VA. W

24VAC.

Y

SEC.

R3

BL 12

CLOSE-A

BL

R

BR

R1 BR

OPEN-B

C

N.O.

OPEN
SAFETY EDGE

OR 1

AUX.

10 CLOSE L/S

GY

OR

OP

OPEN L.S.

OR N.C.

W 11
C

OPEN/CLOSE 7

Y R2 Y

AUX. OPEN L/S

CLOSE

P

2

P

CL

TO REVERSE MOTOR ROTATION, INTERCHANGE RED AND YELLOW MOTOR WIRES.

W

CLOSE L/S

P N.C.

CW

12

THREE PHASE SCHEMATIC DIAGRAM FOR MGJ ONLY

230V BRAKE (WHEN PRESENT)
230V BRAKE (WHEN PRESENT)

BRN GY PUR YEL BRN

BL/BK
1 74 2 8 5 O/L* 3 96
BL/BK

BRN GY PUR YEL BRN

BL/BK
1 74 2 8 5 O/L* 3 96
BL/BK

230 VOLT – 3 PHASE MOTOR CONNECTION

460 VOLT – 3 PHASE MOTOR CONNECTION

L3
3 PHASE POWER IN L2
L1

(BK)
(BK) (BK)

3 (YEL)

STOP

OPEN

(BR)
EXTERNAL 4 INTERLOCK

(GY)

CL

4

3

OP

4

3

OP

2

1

CL

6

5

OP

5

6

CL

1

2

TO MOTOR (PUR)

(BK)

(YEL) (BK)

5 (BRN)
(YEL) 14 OP
1 (OR) 13

OVERLOAD (IN MOTOR)

PRI.

T1 (SEE NOTE #1)

(BRN) 24VAC SEC.

(YEL)

(OR)

OPEN

A1

OP

(OR) LIMIT SWITCH

A2 NC

C

(OR)

WIRE NUT

(OR)

SAFETY EDGE R1 (OR)

AUX. CLOSE

10 (GY) LIMIT SWITCH

NC

C (GY)

(OR)

(RED)

R1 (RED)

R3 (RED)

OPEN & CLOSE

7

(OR)

RADIO TO OPEN & CLOSE

R1

R2

CLOSE

(YEL)

(RED) NOTE: Voltage same as line voltage.

(YEL)

NC

AUX. OPEN

C

LIMIT SWITCH

NO

(PUR) 2 (PUR)

(PUR) R1

14 CL

(PAU2R)CL

CLOSE

LIMIT SWITCH

(PUR)

A1 NC

C

(RED) 13

– Shipped from Factory CLOSE CONTROL WIRING OPTIONS
C2 WIRING – Constant Presssure to Close
RED WIRE ON TERMINAL #2 (Shipped from Factory)
B2 WIRING – Momentary Contact to Close MOVE RED WIRE FROM TERMINAL #2 TO TERMINAL #3

13

MAINTENANCE

MAINTENANCE SCHEDULE
Check at the intervals listed in the following chart:

ITEM Drive Chain
Sprockets Fasteners Manual Disconnect Bearing & Shafts

PROCEDURE Check for excessive slack. Check & adjust as required. Lubricate. * Check set screw tightness Check and tighten as required Check & Operate Check for wear & lubricate

EVERY 3 MONTHS
z z
z

EVERY 6 MONTHS
z z

EVERY 12 MONTHS

WARNING
To avoid SERIOUS PERSONAL INJURY or DEATH from electrocution, disconnect ALL electric power BEFORE performing ANY maintenance.
6 Use SAE 30 Oil (Never use grease or silicone spray).
Repeat ALL procedures. Do not lubricate motor. Motor bearings are rated for
continuous operation. Inspect and service whenever a malfunction is
observed or suspected. CAUTION: BEFORE SERVICING, ALWAYS
DISCONNECT OPERATOR FROM POWER SUPPLY.

HOW TO ORDER REPAIR PARTS
OUR LARGE SERVICE ORGANIZATION SPANS AMERICA Installation and service information are available. Call our TOLL FREE number: 1-800-528-2806 www.liftmaster.com

14

THIS PAGE INTENTIONALLY LEFT BLANK

MGH ILLUSTRATED PARTS
11 1

4 2

K2 (K72-12789) 9

5 3

6 7 8

K1 (K75-12783)

10

K3 (K75-12829)
16

REPLACEMENT PART KITS MGH
Refer to the parts lists below for replacement kits available for your operator. If optional modifications and/or accessories are included with your operator, certain components may be added or removed from these lists.

SERVICE KITS

Item Part # K1 K75-12783
K2 K72-12789
K3 K75-12829

Description Disconnect assembly Complete with: Bevel gear yoke, disconnect release lever, retaining plate, disconnect shaft sprocket, compression spring, key, screws, flatwasher, cotter pin, roll pin and e-ring. Hand chain shaft kit (1/2 thru 2 HP) Complete with: Bevel gear 5/8″ ID, bevel gear 3/4″ ID, hand chain guide, hand chain shaft, bearing 3/4″ ID, nyliner bearing, compression spring, chain wheel, washers, roll pins and e-rings. Gear housing kit (Includes all parts from K2) Complete with: Housing support bracket, pads and pressure plate, housing with cover, disconnect kit, hand chain shaft and brake kit.

INDIVIDUAL PARTS

Item Part # 1 K20-1050C-1M-1 K20-1075C-1M 2 32-34291 3 23-10916 4 15-41B19LKGFO 5 15-48B19LKGEO 6 75-10884 7 10-10882 8 08-11013 9 08-11012 10 K10-34319 11 (see page 19)

Description 1/2 HP Motor 3/4 HP Motor Gear reducer Switch assembly interlock Sprocket Sprocket Chain assembly wheel Hand chain guide Gear Bevel gear Gear housing cover Complete electrical box

17

MGJ/MGH ELECTRICAL BOX – ILLUSTRATED PARTS

3
K1 (K75-12567) 1

9
5 7
9

1

3

8

6

2

4
18

ELECTRICAL BOX- MODELS MGJ & MGH
For replacement of electrical box, motor or brake components be sure to match model number of your unit to kit number below to ensure proper voltage requirements.

SERVICE KITS

ITEM PART #

DESCRIPTION

K1 K72-12565 Limit shaft assembly

Complete with: Limit shaft, limit nuts,

plastic flange bearing, limit sprocket,

washer, flatwashers, roll pin,

and e-ring.

K2 K72-12566 Limit shaft assembly

Complete with: Depress plate, depress

spring plate, limit switches, spacers,

screws, nuts, and locknuts.

· To order a complete electrical box kit, add a K- prefix to the

model number of your operator. For example:

T5011L3 (Operator) = K-T5011L3 (Electrical box kit).

INDIVIDUAL PARTS

ITEM 1 2 3 4
5 6
7 8 9

PART # 13-10024 10-11403 03-11112 21-5115 21-5230 21-5460 24-24-1 29-10338
30B652
29-2 15-58B07AXX 23-10041

DESCRIPTION
Limit nut
Electrical box cover
Reversing contactor (See note)
Transformer, 115V Transformer, 230V Transformer, 460V
Relay, 24V DPDT
Capacitor – 1/2 HP 70 MFD with bracket Capacitor – 3/4 HP 89 MFD with screw
Resistor, 200hm
Sprocket 48B07
Limit switch SPDT

NOTE: Reversing Contactor (03-8024-K), used only on three phase operators. Single phase operators use relays.

19

2

3

5 K1 K75-12567

ILLUSTRATED PARTS – MODEL MGJ
20

4

1

REPLACEMENT PART KITS MGJ

Below are replacement kits available for your operator. For replacement of electrical box, motor or brake components be sure to match model number of your unit to kit number below to ensure proper voltage requirements.

MOTOR KITS K20-1050C-1M-1 K20-3050C4M K20-5150C6M K20-1075C-1M

Model MGJ5011 Models MGJ5023,MGJ5038,MGJ5043 Model MGJ5025 Model MGJ7511

Refer to the parts lists below for replacement kits available for your operator. If optional modifications and/or accessories are included with your operator, certain components may be added or removed from these lists.

ITEM K1

PART # K75-12567

SERVICE KITS
DESCRIPTION Disconnect assembly kit Complete with: Disconnect hub, bevel gear yoke, disconnect shaft, release lever, disconnect support bracket, sprocket 41B19 x 1.25 bore, compression spring, sash chain (12′) disconnect key, screws, lockwashers, cotter pins, roll pins and e-rings.

INDIVIDUAL PARTS

ITEM 1 2 3 4 5

PART #
32-11414 See Page 19 K20-1050C-1M-1 K20-3050C4M

K20-5150C6M K20-1075-1M

DESCRIPTION Brake mounting plate Front bracket Gear reducer, 45:1 Electrical Box Motor – model MGJ5011 Motor – models MGJ5023, MGJ5038, and MGJ5043 Motor – model MGJ5025 Motor – model MGJ7511

21

OPERATOR NOTES
22

OPERATOR NOTES
23

CONTROL CONNECTION DIAGRAM

IMPORTANT NOTES:
1. The 3-Button Control Station provided must be connected for operation. 2. If a STOP button is not used, a jumper must be placed between terminals 3 and 4. 3. When adding accessories, install them one at a time and test each one after it is added to
ensure proper installation and operation with the Commercial Door Operator. 4. Auxiliary control equipment may be any normally open two wire device such as
pull switch, single button, loop detector, card key or such device.

ATTENTION ELECTRICIAN: USE 16 GAUGE OR HEAVIER WIRE FOR ALL CONTROL CIRCUIT WIRING.

3 BUTTON STATION or 3 POSITION KEYSWITCH w/ SPRING RETURN TO CENTER AND STOP BUTTON

1 BUTTON STATION or ANY AUXILIARY DEVICE

STANDARD 1 234

2 OR MORE 1 234

KEY LOCKOUT 1 234

Open
Close
Stop ALL CONTROL WIRING TYPES

Open

Close Stop

ALL CONTROL WIRING TYPES

Open
Close Stop Keyswitch ALL CONTROL WIRING TYPES

2 BUTTON STATION or 3 POSITION KEYSWITCH w/ SPRING RETURN TO CENTER