Mighty Mule FM700 User manual

©2000 GTO, Inc.
RB901
rev - 11/05/02
Installation Manual
for the
Automatic Gate Opener System
FOR SINGLE SWING GATES
WARNING!
This equipment is similar to other gate or door equipment and meets or exceeds
Underwriters Laboratory Standard 325 (UL 325). However, gate equipment has
hazards associated with its use and therefore by installing this product the
installer and user accept full responsibility for following and noting the
installation and safety instructions. Failure to follow installation and safety
instructions can result in hazards developing due to improper assembly. You agree
to properly install this product and that if you fail to do so GTO, Inc. shall in no
event be liable for direct, indirect, incidental, special or consequential damages or
loss of profits whether based in contract tort or any other legal theory during the
course of the warranty or at any time thereafter. The installer and/or user agree to
assume responsibility for all liability and use of this product releasing GTO, Inc.
from any and all liability. If you are not in agreement with this disclaimer or do
not feel capable of properly following all installation and safety instructions you
may return this product for full replacement value.
READ ALL INSTRUCTIONS CAREFULLY AND COMPLETELY before
attempting to install and use this automatic gate opener. This gate opener
produces a high level of force. Stay clear of the unit while it is operating and
exercise caution at all times.
All automatic gate openers are intended for use on vehicular gates only.
This product meets and exceeds the requirements of UL 325, the standard which regulates gate opener safety,
as established and made effective March 1, 2000, by Underwriters Laboratories Inc.
®
E-Z GATE OPENER
3121 Hartsfield Road • Tallahassee, Florida, USA 32303
Telephone GTO Sales: 1-800-543-GATE (4283) or [phone] • Fax [phone]
or GTO Technical Service: 1-800-543-1236 or [phone] • Fax [phone]
www.mightymule.com

VEHICULAR GATE OPENER CLASS CATEGORIES
Residential Vehicular Gate Opener-Class I: A vehicular gate opener (or system) intended for use in a home of
one-to-four single family dwelling, or a garage or parking area associated therewith.
Commercial/General Access Vehicular Gate Opener-Class II: A vehicular gate opener (or system) intended for
use in a commercial location or building such as a multifamily housing unit (five or more single family units),
hotel, garages, retail store, or other building servicing the general public.
Industrial/Limited Access Vehicular Gate Opener–Class III: A vehicular gate opener (or system) intended for
use in an industrial location or building such as a factory or loading dock area or other locations not intended to
service the general public.
Restricted Access Vehicular Gate Opener–Class IV: A vehicular gate opener (or system) intended for use in a
guarded industrial location or building such as an airport security area or other restricted access locations not
servicing the general public, in which unauthorized access is prevented via supervision by security personnel.
The Mighty Mule Gate Opener®is intended for use with vehicular swing gates. The opener can be used in Class I,
Class II and Class III applications.
FOR YOUR RECORDS
Please record the product serial number (located on the control box cover), and the date
and place of purchase in the spaces provided below. Refer to this information when
calling GTO for service or assistance with your automatic gate opener.
Serial Number ____________________ Date of Purchase ____________________
Place of Purchase ____________________
Remember to keep all receipts for proof of purchase.
Converting Metric Units to English Equivalents
When You Know Multiply By To Find Symbol
centimeters 0.3937 inches in. (or ")
meters 3.2808 feet ft. (or ')
kilograms 2.2046 pounds lb. (or #)
Converting English Units to Metric Equivalents
When You Know Multiply By To Find Symbol
inches 2.5400 centimeters cm
feet 0.3048 meters m
pounds 0.4535 kilograms kg
Converting Temperature
deg. Celsius (ºC x 1.8) + 32 deg. Fahrenheit ºF
deg. Fahrenheit (ºF-32) ÷1.8 deg. Celsius ºC
Conversion Chart

Gate Opener Class Categories -------------------------------------------------------------inside cover
Units and Standards Conversion Chart ---------------------------------------------------inside cover
PLEASE READ THIS FIRST! ------------------------------------------------- page iii
Important Safety Instructions -------------------------------------------------- page 1
Disconnecting the Opener -------------------------------------------------------------page 1
Important Safety Instructions for the Consumer -----------------------------------page 2
Secondary Means of Protection Against Entrapment -----------------------------page 5
Required Safety Precautions for Gates --------------------------------------------- page 6
Warning Signs and Labels ------------------------------------------------------------page 7
Installation-------------------------------------------------------------------------- page 8
Parts List ---------------------------------------------------------------------------------page 8
Technical Specifications---------------------------------------------------------------page 10
Installation Overview ---------------------------------------------------------------- page 11
Installation of the Mounting Hardware--------------------------------------------- page 12
Mounting the Opener ------------------------------------------------------------------page 16
Installation of the Positive Stops -----------------------------------------------------page 16
Mounting the Control Box ------------------------------------------------------------page 18
Setting the Closed Position -----------------------------------------------------------page 19
Powering the System ------------------------------------------------------------- page 20
Solar Chart ------------------------------------------------------------------------------page 20
Connecting the Transformer ----------------------------------------------------------page 22
Control Board Settings----------------------------------------------------------- page 23
DIP Switches ----------------------------------------------------------------------------page 23
Potentiometers --------------------------------------------------------------------------page 24
Setting Your Personal Transmitter Code ------------------------------------ page 25
Mounting the Receiver ----------------------------------------------------------- page 26
Connecting Additional Safety Devices ---------------------------------------- page 27
Connecting Accessories ---------------------------------------------------------- page 28
Push to Open Installation ------------------------------------------------------- page 29
Maintenance & Troubleshooting Guide -------------------------------------- page 31
Warranty and Repair Service -------------------------------------------------- page 33
Column Installation Information ---------------------------------------------- page 34
Accessory Catalog----------------------------------------------------------------- page 35
4 1/2" x 4 1/2" Setback Template ---------------------------------------------- insert
Table of Contents
KEEP THESE INSTRUCTIONS FOR FUTURE REFERENCE

PLEASE READ THIS FIRST!
iii
BEFORE YOU BEGIN TO INSTALL YOUR AUTOMATIC GATE OPENER:
watch the enclosed videotape and read these instructions carefully and completely
to become familiar with all parts and installation steps.
®
E-Z GATE OPENER
Thank you for purchasing a Mighty Mule E-Z Gate Opener—GTO's "do-it-yourself" automatic gate opener! When
correctly installed and properly used, your Mighty Mule E-Z Gate Opener will give you many years of reliable
service. Please read the following information and watch the enclosed videotape to ensure you have the correct system
for your particular needs. Furthermore, this manual and the videotape will enable you to properly install your Mighty
Mule E-Z Gate Opener.
The Mighty Mule E-Z Gate Opener is designed for installation on a pull-to-open single leaf gate (gates that open
into the property). Using an accessory bracket, the Mighty Mule E-Z Gate Opener can accommodate a push-to-
open single leaf gate (gates that open out from the property). The gate must not exceed 16 feet in length nor weigh
more than 350 pounds (please see Technical Specifications on page 10). The Mighty Mule E-Z Gate Opener can be
used on vinyl, aluminum, chain link, farm tube, and wrought iron gates. Use on solid (wood) gates is not
recommended. Solid surface gates have a high resistance to the wind; if the wind is strong enough, the opener will
obstruct and stop.
The Mighty Mule E-Z Gate Opener accommodates extra transmitters, digital keypads, solar panels, push buttons,
automatic gate locks, and other access control products. These optional accessories (see the enclosed Mighty Mule
Accessory Catalog) are available at most stores. Your store should be able to special order any accessory not in stock.
If your store cannot special order accessories, please call the GTO Sales Department.
The Mighty Mule E-Z Gate Opener features adjustable obstruction sensing. This safety feature makes the gate
stop and reverse direction within 2 seconds when it comes in contact with an obstruction. MIN is the factory setting;
meaning the gate will exert the minimum force on an obstruction before it stops and reverses direction.
The Mighty Mule E-Z Gate Opener also has an adjustable auto-close feature. After the gate reaches the fully open
position, it can be set to remain open for 1 to 120 seconds before automatically closing. Pressing the transmitter
button at any time after the gate opens fully will cause it to close immediately. OFF is the factory setting; meaning the
gate will stay open until you press the transmitter (or keypad, etc.) again.
PLEASE NOTE—If your application requires any of the following:
Swing gates longer than 16 feet or weighing more than 350 pounds;
Slide gates;
Heavy duty or commercial uses;
Professional installation;
please call GTO at (800) 543-GATE [4283] or [phone] for information about our GTO/PRO professional line
of gate openers and accessories. Our Sales Department will be glad to give you the name and phone number of a
GTO/PRO dealer near you.

1
IMPORTANT SAFETY INSTRUCTIONS
Because automatic gate openers produce high levels of force, consumers need to know the potential hazards associated with
improperly designed, installed, and maintained gate opener systems. Keep in mind that the gate opener is just one
component of the total gate operating system. Each component must work in unison to provide the consumer with
convenience, security, and safety.
This manual contains various safety precautions and warnings for the consumer. Because there are many possible
applications of the gate opener, the safety precautions and warnings contained in this manual cannot be completely
exhaustive in nature. They do, however, provide an overview of the safe design, installation, and use of this product.
CAREFULLY READ AND FOLLOW ALL SAFETY PRECAUTIONS, WARNINGS, AND INSTALLATION
INSTRUCTIONS TO ENSURE THE SAFE SYSTEM DESIGN, INSTALLATION, AND USE OF THIS PRODUCT.
Precautions and warnings in this manual are identified with this warning symbol. The symbol identifies conditions
that can result in damage to the opener or its components, serious injury, or death.
Because GTO automatic gate openers are only part of the total gate operating system, it is the responsibility of the
consumer to ensure that the total system is safe for its intended use.
Clevis Pin
Hairpin Clip
Washer
Gate Bracket
Front Mount
Disconnecting the Opener
1. Turn control box power switch OFF.
2. Remove hairpin clip, clevis pin, and washer from
front mount.
3. Pull front mount away from gate bracket.
The gate can be opened and closed manually when the
opener is disconnected.
NOTE: Substitute Pin Locks for the clevis
pins to prevent unauthorized removal of the
opener from the gate (see Accessory
catalog).
To Manually Open and Close
the Gate, Follow the Procedure
Below:
CAUTION: Disconnect the
opener ONLY when the control
box power switch is OFF and
the gate is NOT moving.

2
IMPORTANT SAFETY INSTRUCTIONS
For The Consumer
WARNING: To reduce the risk of injury or death:
1. READ AND FOLLOW ALL INSTRUCTIONS. Failure to meet the requirements set forth in the instruction
manual could cause severe injury and/or death, for which the manufacturer cannot be held responsible.
2. When designing a system that will be entered from a highway or main thoroughfare, make sure the system is placed
far enough from the road to prevent traffic congestion.
3. The gate must be installed in a location that provides adequate clearance between it and adjacent structures when
opening and closing to reduce the risk of entrapment. Swinging gates must not open into public access areas.
4. The gate and gate opener installation must comply with any applicable local codes.
I. Before Installation
1. Verify this opener is proper for the type and size of gate, its frequency of use and the proper class rating.
2. Make sure the gate has been properly installed and swings freely in both directions. Repair or replace all worn or
damaged gate hardware prior to installation. A freely moving gate will require less force to operate and will
enhance the performance of the opener and safety devices used with the system.
3. Review the operation of the system to become familiar with its safety features. Understand how to disconnect the
opener for manual gate operation (see page 1).
4. This gate opener is intended for vehicular gates ONLY. A separate entrance or gate must be installed for pedestrian
use (see page 6).
5. Always keep people and objects away from the gate and its area of travel. NO ONE SHOULD CROSS THE
PATH OF A MOVING GATE.
6. Pay close attention to the diagram below and be aware of these areas at all times.
Gate in the 
Open Position
ZONE 2
ZONE 3
ZONE 4
ZONE 5
Driveway
ZONE 1

3
IMPORTANT SAFETY INSTRUCTIONS
Entrapment Zones:
Zone 1 – leading edge of the gate and the fence post.
Zone 2 – between the gate and the gate post
Zone 3 – the path of the gate
Zone 4 – the space between the gate in the open position and any object such as a wall, fence, tree, etc.
Zone 5 – pinch points between the opener and gate or post
II. During Installation
1. Install the gate opener on the inside of the property and fence line. DO NOT install an opener on the outside of the
gate where the public has access to it.
2. Be careful with moving parts and avoid close proximity to areas where fingers or hands could be pinched.
3. Devices such as safety edges and photo beams provide additional protection against entrapment (see page 5).
4. If push buttons or key switches are installed, they should be within sight of the gate, yet located at least 10 feet from
any moving part of the gate (see diagram below). Never install any control device where a user will be tempted to
reach through the gate to activate the gate opener.
5. Do not activate your gate opener unless you can see it and can determine that its area of travel is clear of people,
pets, or other obstructions. Watch the gate through its entire movement.
6. Secure outdoor or easily accessed gate opener controls in order to prohibit unauthorized use of the gate.
Moving Gate
Area
Driveway
10'
10'
10'
10'
NEVER INSTALL
any control device
within gray area

4
IMPORTANT SAFETY INSTRUCTIONS
III. After Installation
1. Attach the warning signs (included) to each side of the gate to alert the public of automatic gate operation. It is
your responsibility to post warning signs on both sides of your gate. If any of these signs or warning decals become
damaged, illegible or missing, replace them immediately. Contact GTO for free replacements.
2. The gate is automatic and could move at any time, posing a serious risk of entrapment. No one should be in contact
with the gate when it is moving or stationary.
3. Do not attempt to drive into the gate area while the gate is moving; wait until the gate comes to a complete stop.
4. Do not attempt to "beat the gate" while the gate is closing. This is extremely dangerous.
5. Do not allow children or pets near your gate. Never let children operate or play with gate controls. Keep the
remote controls away from children and unauthorized users; store controls where children and unauthorized users do
not have access to them.
6. KEEP GATES PROPERLY MAINTAINED. Always turn power to opener OFF before performing any
maintenance. Clean the push-pull tube with a soft, dry cloth and apply silicone spray to it at least once per month.
7. Service the gate and gate opener regularly. Grease hinges, spray push pull tube with high quality silicon spray and
replace the battery every 3-5 years.
8. To operate this equipment safely, YOU must know how to disconnect the opener for manual gate operation
(see page 1). If you have read the instructions and still do not understand how to disconnect the opener, contact the
GTO Service Department.
9. Disconnect the opener ONLY when the power is TURNED OFF and the gate is NOT moving.
10. Make arrangements with local fire and law enforcement for emergency access.
11. Distribute and discuss copies of the IMPORTANT SAFETY INSTRUCTIONS section of this manual with all
persons authorized to use your gate.
12. IMPORTANT: Save these safety instructions. Make sure everyone who is
using or will be around the gate and gate opener are aware of the dangers
associated with automated gates. In the event you sell the property with the
gate opener or sell the gate opener, provide a copy of these safety instructions
to the new owner.
Should you lose or misplace this manual, a copy can be obtained by
downloading one from the Mighty Mule web site (www.mightymule.com), by
contacting GTO, Inc., at 3121 Hartsfield Road, Tallahassee, Florida 32303 or
by calling 1-800-543-4283 and requesting a duplicate copy. One will be
provided to you free of charge.

5
IMPORTANT SAFETY INSTRUCTIONS
ENTRAPMENT ALARM (UL 325; 30A.1.1A)
The Mighty Mule E-Z Gate Opener is designed to stop and reverse within 2 seconds when the gate comes in contact
with an obstruction or when an object activates the non-contact sensors. Additionally, these openers are equipped
with an audio entrapment alarm which will activate if the unit obstructs twice while opening or closing. This
alarm will sound for a period of 5 minutes, or until the opener receives an intended signal (e.g., from a transmitter)
and the gate returns to a fully open or fully closed position.
Secondary Means of Protection Against
Entrapment
As specified by Gate Operator Safety Standard, UL 325 (30A.1.1), automatic gate openers shall have an inherent entrapment
sensing system, and shall have provisions for, or be supplied with, at least one independent secondary means to protect
against entrapment. The Mighty Mule utilizes Type A, an inherent (i.e., built-in) entrapment sensing system as the primary
type of entrapment protection. Also, the Mighty Mule has provisions for the connection of Type B2 protection to be used as
the secondary type of entrapment protection, if desired.
1. For gate operators utilizing a contact sensor (e.g., safety edge sensor– Type B2) in accordance with UL 325 (51.8.4 [i]):
A. One or more contact sensors shall be located at the leading edge, bottom edge, and post edge, both inside and
outside of a vehicular swing gate system.
B. A hard wired contact sensor shall be located and its wiring arranged so that the communication between the
sensor and the gate opener is not subjected to mechanical damage.
C. A wireless contact sensor such as one that transmits radio frequency (RF) signals to the gate opener for
entrapment protection functions shall be located where the transmission of the signals are not obstructed or
impeded by building structures, natural landscaping or similar obstruction. A wireless contact sensor shall
function under the intended end-use conditions.
Vehicular Gate
Leading Edge Contact Sensor
on both sides of the gate
Bottom Edge Contact Sensor
on both sides of the gate
Post Edge Contact Sensor
on both sides of the gate

6
IMPORTANT SAFETY INSTRUCTIONS
Install Warning Signs
Entrapment Protection
GTO’s inherent obstruction settings, even when properly adjusted, may not be sensitive enough to prevent bodily injury in
some circumstances. For this reason, safety devices such as safety edge sensors (or photoelectric sensors), which stop and
reverse gate direction upon sensing an obstruction, are suggested for augmented protection against entrapment.
Required Safety Precautions for Gates
Warning Signs
The warning signs (at right) must
be installed on both sides of the
gate (see page 7 for details).
Warning signs alert people of automatic gate operation and are required when installing the Mighty Mule E-Z Gate Opener.
Furthermore, a walk-through gate must be installed if pedestrian traffic is expected near the vehicular gate. We recommend
using the GTO Bulldog Pedestrian Gate Lock (Call the GTO Sales Department) for controlled access.
1. KEEP CLEAR! Gate may move at any time.
2. Do not allow children to operate gate or
play in gate area.
3. This gate is for vehicles only. Pedestrians
must use a separate entrance.
Moving Gate Can Cause
Injury Or Death
WARNING
!
Warning Sign
Pedestrian Gate
Bulldog Pedestrian
Gate Lock
Vehicular Gate
Contact Sensor
(recommended, not included)
Contact Sensor
(recommended, not included)
Contact Sensor
(recommended, not included)
(recommended, not included )

7
IMPORTANT SAFETY INSTRUCTIONS
These warning labels should be found at the locations specified below. If any of them are missing, immediately contact GTO
for replacements.
1. KEEP CLEAR! Gate may move at any time.
2. Do not allow children to operate gate or
play in gate area.
3. This gate is for vehicles only. Pedestrians
must use a separate entrance.
Moving Gate Can Cause
Injury Or Death
WARNING
!
warning signs (2 enclosed) to be installed on each side
of the gate (3–5 feet above the bottom of the gate)
WARNING
!
MOVING GATE
Can Cause Injury or Death
1. KEEP CLEAR! Gate may move at any time.
2. Do not allow children to operate gate or play in gate area.
3. This gate is for vehicles only. Pedestrians must use
separate entrance.
warning labels (2) installed on each side of
operator housing
RB2000
Maximum Gate: 500 lb. (226.7 kg); 16 ft. (4.8 m)
Voltage: 12 Vdc; Frequency: 0 Hz; Power: 41.4 W
Class I, II and III Vehicular Swing Gate Operator.
Serial Number: XXXXXXXXXX
#xxxxxxx
Conforms to UL 325 STANDARDS
TO MANUALLY OPEN AND CLOSE THE GATE:
1. Turn control box power switch OFF.
2. Disconnect front mount from gate bracket.
3. Pull front mount away from gate bracket.
Series
GTO, Inc. Tallahassee, Florida USA
Disconnect operator ONLY when the control box power
switch is OFF and the gate is NOT moving.
L
I
S
T
E
D
USC
product identification and manual operation instruction label (1)
installed on control box cover

8
Single Gate Opener Parts List
Opener and Mounting Hardware
SeeInstallationof thePost BracketAssembly
pages 5and6 in the InstallationManual
Hairpin Clip (2)
3/8" x 1-1/8" Clevis Pin (2)
5/16" x 1-3/4" Bolt (1)
3/8" x 2" Bolt (1)
3/8" x 3" Bolt (2)
3/8" x 8" Bolt (4)
8" Nylon Cable Tie (14)
3/8" Washer (9)
3/8" Lock Washer (7)
5/16" Washer (1)
3/8" Nut (7)
5/16" Nut (1)
Hardware
Gate Opener (1)
Installation Video (1)
Gate Bracket (1)
4 1/2" x 4 1/2"
Setback Template (1)
Post Pivot Bracket (1)
Customer Support Card (1)
Post Bracket (2)
Closed Position
Stop Plate (1)
4 1/2' Power Cable (1)
2" Receiver Mounting Screw (1)
®
AUTOMATIC GATE OPENER
®
E-Z GATEOPENER

9
Tools Needed
• Power Drill
• Open End Wrenches — 3/8", 7/16", 1/2", and 9/16"
• 3/8" Drill Bit
• Hacksaw or Heavy Duty Bolt Cutters
• Slotted (Flat Bladed) Screwdriver
• Phillips Screwdriver
• Tape Measure
• Level
• Wire Strippers
• C-Clamps — small, medium, and large
Single Gate Opener Parts List (continued)
Control Box and Electrical Components
ALSO, YOU WILL NEED THESE ITEMS BEFORE YOU BEGIN THE INSTALLATION (Some of these items can
be found in the Accessory Catalog on page 35):
•The gate needs a stop post for the open position. This post is not provided. See Installation of the Positive Stops
on page 16 for more information.
• Additional low voltage wire may be needed; length depends upon the distance between the transformer power
supply and the control box. See Powering the System on page 20, and the Accessory Catalog.
•If your gate is more than 1000' away from an ac power source you will need to use at least one Mighty Mule Solar
Panel to trickle charge the battery. See the Accessory Catalog.
• If your fence post is made of wood and is less than 6" in diameter or 6" square, see page 12.
•If your fence post is larger than 6" in diameter you will need threaded rods or carriage bolts longer than 8". See
page 15.
•If you have thin walled tube or panel gates, see Recommended Reinforcement Examples on page 12.
•Depending on the type of gate, a horizontal cross member or mounting plate may be needed to mount the front
of the opener and gate bracket to the gate. See page 11, step 2; page 15, step 10.
•Power cables 40' long are available for mounting your control box away from the gate (i.e., in a more secure
location). See the Accessory Catalog.
Transformer (1)
Battery (1)
Control Box Lid (1) Control Box (1)
Warning Signs (2)
GTO Transmitter(1)
1. KEEP CLEAR! Gate may move at any time.
2. Do not allow children to operate gate or
play in gate area.
3. This gate is for vehicles only. Pedestrians
must use a separate entrance.
Moving Gate Can Cause
Injury Or Death
WARNING
!
Receiver (1)



10
DRIVE
•Low friction screw drive (linear actuator) rated for -20 ºF to +160 ºF (-28 ºC to +71 ºC).
•Powered by a 12 V motor with integral case hardened steel gear reducer. Motor speed reduced to 220 rpm. Generates
330 ft.. lb. of torque at 12 V.
•Maximum opening arc of 110º. Approximate opening time (90º): 15 to 17 s, depending on weight of gate.
POWER
•The system is powered by a 12 Vdc, 7.0 Ah, sealed, rechargeable acid battery.
•Battery charge is maintained by a 120 Vac, 18 Vac output transformer rectified to 14.5 Vdc (20 VA) through the GTO
control board. Two (2) blade-style control board fuses are rated for 15 A.
NOTE: The transformer should not be directly connected to any battery. Do not replace fuses
with higher ampere rated fuses; doing so will void your warranty and may damage your control board.
•Battery charge is maintained by GTO Solar Panel Charger: float voltage of 14.5 Vdc output from a 193/8" x 81
/2"
silicon alloy panel. Generates minimum of 5 W at 300 mA. A gated diode on the control board prevents battery
discharge.
CONTROL
•GTO microprocessor-based control board is set for single leaf, pull-to-open gate installations. DIP switches can be
adjusted to accommodate an optional kit for push-to-open gates (see Accessory Catalog).
•Control board has temperature compensated circuits.
•Acircuit on the control board regulates charging. "Sleep draw" is 40 mA; "active draw" is 2 to 5 A.
•Auto-memorization of digital transmitter code.
•GTO remote-mounted RF receiver tuned to 318 MHz.
•Limit controls are mechanical. Adjustable range of push-pull tube is 71
/2" to 111 /2". Opener length with push-pull
tube fully retracted is 333/4", mounting point to mounting point.
•Adjustable auto-close timer (OFF to 120 s), inertia, and obstruction sensitivity using three (3) potentiometers.
•Power terminal bock accommodates a transformer and solar panels.
•DIP switches simplify setup of gate opener.
•Accessory terminal block fully compatible with push button controls, digital keypads, safety loops, etc.
•Control board allows connection of safety edge sensors and photoelectric sensors.
•Audio entrapment alarm sounds if unit encounters an obstruction twice while opening or closing.
OPERATIONAL CAPACITY
•Depending upon the length of the gate leaves and the number of operational cycles*per day, the Mighty Mule Gate
Opener® can open single gates weighing up to 350 lb.—if all installation procedures have been
properly followed.
NOTE: BALL BEARING HINGES SHOULD BE USED ON ALL GATES WEIGHING OVER 250 LB.
To determine the number of cycles the gate opener will perform using solar panels, please see the specifications listed
on page 20 or call [phone] or [phone] for more information.
* An operation cycle is one full opening and closing of the gate.
MIGHTY MULE GATE OPENER
Technical Specifications
These specifications are subject to change without notice.
Gate Weight
Gate Length
Gate Capacity Chart (estimated number of cycles based on use with a transformer)
16 ft.
14 ft.
12 ft.
3.5-10 ft.
135
145
155
165
120
130
140
150
105
115
125
135
NONE
85
95
105
NONE
NONE
60
70
50 lb. 100 lb. 150 lb. 250 lb. 350 lb.

11
Horizontal Cross Member
Gate Swings Evenly and Freely
Hung Firmly and Plumb
Receiver
Post Bracket Assembly
Control Box with Battery
Gate Bracket
Single Gate Opener
Fence Post Set in Concrete
Run 1000’ (max.) of low
voltage wire to control
box from transformer
(wire not included).
Power Cable
Closed Position Positive Stop Plate
120 Volt indoor
Transformer
(surge protector
not supplied)
PVC conduit (not included)
to protect wire from lawn
mowers and weed eaters.
Warning Sign
Preparation of the Gate
Step 1
The gate must be plumb, level, and swing freely on its
hinges. Wheels must not be attached to the gate. The
gate must move throughout its arc without binding or
dragging on the ground. Note that gates over 250 lb.
should have ball bearing hinges with grease fittings.
Step 2
The fence post must be secured in the ground with
concrete so it will not twist or flex when the opener is
activated. Be sure to position the opener near the
centerline of the gate to keep the gate from twisting and
flexing. The addition of a horizontal or vertical cross
member (if one is not already in place) to provide a
stable area for mounting the gate bracket is also
important.
Installation Overview
Pull-to-Open Gates (Gate Opens into the Property)
The diagram shown below is an example of a pull-to-open installation on a chain link fence and single gate. Mounting the
opener on a masonry column requires special procedures; see Column Installation Information on page 34 if you intend to
mount the opener on a column. Furthermore, if you have a push-to-open gate, you will need to purchase a push-to-open kit
(see Accessory Catalog) to properly configure your system. See Push to Open Installation on page 29 before proceeding.
Horizontal Cross Member
Vertical Cross Member

12
Installation of Mounting Hardware
The position of the post bracket determines the leverage and efficiency of the opener. The post bracket position also sets the
clearance between the opener and gate in the open and closed positions.
The curved design of the post bracket works well for installations on round and square fence posts. Because the post bracket
carries the entire thrust of the active opener, bolts that completely penetrate the fence post must be used.
On wooden posts, place a metal plate or washer
(not supplied) between the nuts and the fence
post to prevent the thrust of the opener from
pulling the bolts and washers out of the wood.
NOTE: A fence post smaller than 6" in diameter
or 6" square should be made of metal instead of
wood so that it will remain stable while the
opener is moving the gate.
On round posts of 6" diameter or larger, the post pivot bracket may
not be necessary for the installation. In this instance, the two post
brackets are mounted by themselves.
Post 
Bracket
Post 
Pivot Bracket
Metal Plate
Wooden Post
Post
Bracket
Post
Pivot Bracket
Metal Plate
Wooden Post
4 1/2"
4 1/2"
Center of Gate Hinge
Pull-to-Open Installation
Larger than 6" diameter post
Recommended Reinforcement Examples
Thin Walled Tube Gate
Steel Pipe Cut in Half
Gate Bracket
Gate Bracket
Wood or Metal
Reinforcement
Gate Bracket
Panel Gate
1" x 6" Wood Reinforcement
(not supplied)
(not supplied)
IMPORTANT:
We strongly recommend using steel pipe, wood or metal to reinforce thin walled tube gates or wood to reinforce panel gates
as shown. These reinforcement methods will prevent damage to the opener and gate when the opener is installed.
Because the size tube gates vary, it is impossible to provide the appropriate reinforcement material for every application. If
you are unable to locate suitable reinforcement materials, call GTO sales at 1-800-543-4283.

13
Clevis Pin
Hairpin Clip
Post Bracket Assembly
Opener
Washer
Rear Mount
Clevis Pin
Hairpin Clip
Washer
Gate Bracket
Front Mount
Determining the Mounting Position
of the Post Bracket Assembly and the Gate Bracket
Step 5
With the gate in the open position (80º to 110º from its closed position), adjust the post bracket assembly and gate bracket
until the opener is level. While holding the opener level, use C-clamps to temporarily keep the post bracket assembly and
gate bracket in their respective positions on the fence post and gate.
Step 3
Insert the 3/8" x 2" bolt through
the center hole of the post
brackets and post pivot bracket as
shown. Fasten a 3/8" washer and
nut on the end of the bolt. DO
NOT overtighten the nut because
the post pivot bracket will have to
be adjusted later.
Step 4
Attach post bracket assembly and gate bracket to the opener with the clevis pins and washers. Secure the clevis pins with
hairpin clips.
3/8" x 2" Bolt
3/8" Nut
Post Pivot Bracket
Post Bracket
Post Bracket
3/8" Lock Washer
Post Bracket Assembly
3/8" Washer
Level Opener
Fence Post
Gate In Open Position 

LEVEL horizontal cross member
Post Bracket Assembly
Gate Bracket
®
E-Z GATE OPENER
NOTE: The following steps are
intended for pull-to-open gate
installations. If you are mounting
your opener on a push-to-open gate
(e.g., a gate on a sloped driveway)
you will need to purchase a Push To
Open bracket (see Accessory
catalog). Also, see Push-to-Open
Installation beginning on page 29.

14
Step 6
Study the 4 1/2" x 4 1/2" setback template (see insert)provided with this manual. Once you are familiar with its
illustrations, cut and save the template from the insert. The template will determine the correct position of the post pivot
bracket before mounting the opener on the fence post.
Remove hairpin, clevis pin, and washer from front mount and close the gate. Rest disconnected opener on cross member of
gate. Stand inside property next to fence post and place one end of template over center of gate hinge. Place the other end of
template over the post pivot bracket hole (either of the two mounting holes in post pivot bracket can be used) where the
opener will be attached. Be sure to hold the template at a 90º angle between these two points and measure 4 1/2" back from
the center of the gate hinge. You will need to rotate the post pivot bracket or the entire post bracket assembly to align it with
the square angle of the template. THE ANGLE BETWEEN THE GATE HINGE AND THE POST PIVOT BRACKET
MUST MATCH THE ANGLE OF THE SETBACK TEMPLATE.
NOTE: If you move the post pivot bracket, be sure one of the post bracket holes is aligned
with the rest of the assembly (the center hole should already have a bolt through it).
Flipping the Post Pivot Bracket gives more position options.
After verifying that you have complied with the 4 1/2" x 4 1/2" setback, insert the 5/16" x 1 3/4" bolt through the aligned
holes of the post bracket and post pivot bracket (illustrated below) and fasten it with the 5/16" washer and nut.
IMPORTANT: If you loosened the clamp on the post bracket to achieve the 4 1/2" x 4 1/2" setback, tighten it in its new
position and recheck the gate bracket with the gate in the open position (move the gate bracket and re-clamp it if necessary).
IMPORTANT
Verify the Position of the Gate Bracket and Post Bracket
Assembly:
With the gate in the open position, make sure the following conditions are met:
1. The opener is level.
2. The 4 1/2" x 4 1/2" setback measurement is correct (Step 6).
3. There is sufficient clearance between opener and gate in the open and closed
positions.
Examples of a 4 1/2" x 4 1/2" Setback
4 1/2"
4 1/2"
Center of Gate Hinge
Pull-to-Open Installation
90
o
GATE
5/16" x 1 3/4"
bolt
Metal Post
Post
Bracket
Post
Pivot Bracket
5/16" x 1 3/4"
Bolt
Washer
Pull-to-Open Installation
4 1/2"
4 1/2"
Center of Gate Hinge
90
o
GATE
Closed Position
Open Position
Make sure there is 
adequate clearance 
between opener and 
gate in the open and 
closed positions


15
Installing the Post Bracket Assembly and Gate Bracket
Step 7
Mark reference points for bolt holes on the fence post through middle of bracket slots. Marking reference points in this
manner allows room for adjustment when mounting the post bracket assembly and gate bracket. After marking your
reference points, remove the
opener and brackets from the
fence and gate.
Step 8
Drill 3/8" holes into fence post
as marked.
Step 9
Fasten post bracket assembly to
the fence post using
(4) 3/8" x 8" bolts, washers,
lock washers, and nuts
(provided). Remove excess
bolt length extending beyond
the tightened nuts with a
hacksaw or bolt cutters.
NOTE: In cases where the
fence post has a diameter larger
than 6", threaded rods or
carriage bolts longer than 8"
(not supplied) must be used.
Step 10
Mark reference points for bolt holes on
the gate cross member through middle of
gate bracket slots. Drill 3/8" holes into
the gate cross member as marked.
Mount gate bracket using (2)
3/8" x 3" bolts, washers, lock washers,
and nuts (provided). Cut off excess bolt
length extending beyond the tightened
nuts.
Gate Bracket Mounting Examples
Gate In Open Position 

LEVEL horizontal cross member
Mark cross member through middle of
gate bracket slots and drill 3/8" holes
Round Tube & Chain Link Gate
Square Tube Gate
Mounting Plate 
Created for 
Decorative Gate
(required but not
supplied)

Remove excess bolt length 
with hacksaw or bolt cutters
FRONT VIEW SIDE VIEW
FRONT VIEW
SIDE VIEW
Post Bracket
Assembly
Mark fence post through 
middle of bracket slots
and drill 3/8" holes
Round Metal Post
Round Wood Post
Square Metal Post
Square Wood Post
Remove excess bolt length 
with hacksaw or bolt cutters
SIDE VIEW
TOP VIEW
EXAMPLES

16
Mounting the Opener
Step 11
Attach the opener to the securely bolted post bracket assembly and gate bracket using clevis pins, washers, and hairpin clips,
or optional Pin Locks (see Accessory Catalog). Verify that the opener is level and adjust the post bracket assembly if
necessary.
Installation of the Positive Stops
The positive stops hold the gate firmly in the open and closed positions. The positive stops also form the
boundaries of the gate operating arc and help stabilize the gate. Moreover, a stable gate maintains the long life of
your automatic gate opener system. To further enhance the stability and security of your gate, install the optional
Mighty Mule Automatic Gate Lock®(see Accessory Catalog).
Step 12
With the gate at its maximum open position, measure the
distance from the gate hinge to the end of the gate. At
approximately 2/3of this distance (using the hinge as your
starting point), place a mark on the ground directly under
the gate. Install the open position stop at this mark (see
illustration). The open position stop post may be made of
wood, metal, or concrete and should be firmly secured in the
ground (we recommend setting it in concrete). When the
open position stop post is in the ideal position, the gate will
strike the post just as the opener motor shuts down.
Step 13
Remove hairpin, clevis pin, and washer from front mount
and close the gate (remember to support opener). Fasten the
closed position stop plate to the end of the gate frame on the
gate centerline, but do not tighten it completely. Slide the
stop plate toward the fence post until they touch (see
illustration). Once you have moved the stop plate to the
correct position, tighten its hardware completely.
Use the appropriate hardware for your type of gate (use
U-bolts if you have a tube or chain link gate; wood or lag
screws for wood gates; etc.). This hardware is not provided.
Level Opener
Fence Post Gate In Open Position 

LEVEL horizontal cross member
Post Bracket Assembly
bolted to fence post
Clevis Pin, Washer, and Hairpin Clip
Clevis Pin, Washer, and Hairpin Clip
Gate Bracket bolted
to gate cross member
®
E-Z GATE OPENER
Closed Position 
Stop Plate
Closed Position Stop Plate mounted 
on metal post with U-bolts.
Open Position Stop
Wood, metal, or concrete 
post set in concrete.
Gate Hinge
The gate must open
80º (min.) to 110º (max.)
Fence Post
Gate Post
TOP VIEW
SIDE VIEW