Mighty Mule FM500 User Manual

WARNING

!

MOVING GATE

Can Cause Injury or Death

UL325 SERIES

500

®

E-Z GATE OPENER

1-800-543-GATE (4283) • www.mightymule.com

UL325 SERIES

500

®

E-Z GATE OPENER

SINGLE GATE SYSTEM

Installation Manual for the

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US

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,

Telephone GTO Sales: 1-800-543-GATE (4283) or [phone] • Fax [phone]

or GTO Technical Service: 1-800-543-1236 or [phone] • Fax [phone]

as established and made effective March 1, 2000, by Underwriters Laboratories Inc.

3121 Hartseld Road • Tallahassee, Florida, USA 32303

www.mightymule.com

©

2002 GTO, Inc.

R500INST

rev - 04/03/06

The Mighty Mule® Gate Opener is intended for use with vehicular swing gates. The opener can be used in Class I,
Class II, Class III and Class IV applications.

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.

Conversion Chart

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

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.

Table of Contents

Gate Opener Class Categories ------------------------------------------------------------- inside cover
Units and Standards Conversion Chart ---------------------------------------------------inside cover

PLEASE READ THIS FIRST! --------------------------------------------------page iii

Important Safety Instructions --------------------------------------------------page 1

KEEP THESE INSTRUCTIONS FOR FUTURE REFERENCE

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 Closed Position Stop ---------------------------------------------page 16
Mounting the Control Box -------------------------------------------------------------page 17
Connecting the Power Cable --------------------------------------------------------- page 18

Powering the System --------------------------------------------------------------page 19

Solar Chart -------------------------------------------------------------------------------page 19
Connecting the Transformer -----------------------------------------------------------page 21

Control Board Settings ----------------------------------------------------------page 22

DIP Switches ----------------------------------------------------------------------------page 22
Setting the Closed Position ------------------------------------------------------------ page 23
Obstuction Sensitivity ------------------------------------------------------------------page 24

Setting Your Personal Transmitter Code -------------------------------------page 25

Installing the Receiver -----------------------------------------------------------page 26

Connecting Additional Safety Devices ----------------------------------------page 27

Connecting Accessories ----------------------------------------------------------page 29

Push to Open Installation --------------------------------------------------------page 30

Maintenance & Troubleshooting Guide --------------------------------------page 33

Repair Service ---------------------------------------------------------------------page 35

Column Installation Information ----------------------------------------------page 36

Accessory Catalog ----------------------------------------------------------------page 37

PLEASE READ THIS FIRST!

®

E-Z GATE OPENERS

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). By purchasing 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 18 feet in length

and weigh more than 350 pounds or exceed 6 feet in length and weigh more than 850 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 (800-543-GATE).

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 up 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 18 feet or weighing more than 850 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.

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. The video tape is only designed as

a overview of the installation procedure. You must read the installation manual for detailed

instructions on gate opener safety and proper use of the gate opener.

iii

IMPORTANT SAFETY INSTRUCTIONS

Clevis Pin

Hairpin Clip

Gate Bracket

Front or Rear Mount

Bushing

Because automatic gate openers produce high levels of force, consumers need to know the potential hazards associated with
improperly designed, installed, and maintained automated 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.

To Manually Open and Close the
Gate, Follow the Procedure Below:

CAUTION: The gate will move freely and uncontrolled when the gate opener is
removed from the gate. ONLY disconnect the opener when the control box power

switch is OFF and the gate is NOT moving.

Disconnecting the Opener

1. Turn control box power switch OFF.

2. Remove hairpin clip, clevis pin, and bushing
from either the front or rear mounting point.

3. Remove the opener from the mount.

The gate can be opened and closed manually
when the opener is disconnected.

NOTE: Substitute a Pin Lock for the clevis pin on the front
mount of the gate opener to prevent unauthorized removal of the
opener from the gate (see Accessory Catalog).

1

IMPORTANT SAFETY INSTRUCTIONS

Gate in the
Open Position

ZONE 2

ZONE 3

ZONE 4

ZONE 5

Driveway

ZONE 1

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.

Entrapment
Zones for a
Pull-To-Open
Application

2

IMPORTANT SAFETY INSTRUCTIONS

Moving Gate

Area

Driveway

10'

10'

10'

10'

NEVER INSTALL

any control device

within gray area

Entrapment Zones for a proper Pull-To-Open installation:
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 contact sensors (safety edges) and non contact sensors (photo beams) provide additional protection
against entrapment.

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.

Pull-To-Open
Application

3

IMPORTANT SAFETY INSTRUCTIONS

III. After Installation

1. Attach the warning signs (included) to each side of the gate to alert the public of auto matic 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 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 in the vicinity of 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.

4

IMPORTANT SAFETY INSTRUCTIONS

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

500

Secondary Means of Protection Against
Entrapment

As specified by Gate Opener 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 openers 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.

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. 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 from a hardwired entry/exit source (e.g. push button control or
keypad) and the gate returns to a fully open or fully closed position. Turning the power switch on the control box
OFF and back ON will also deactivate the alarm. Wireless controls such as transmitters and wireless keypads will
not deactivate the alarm.

5

IMPORTANT SAFETY INSTRUCTIONS

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

)

500

Required Safety Precautions for Gates

Install Warning Signs

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.

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 enhanced protection against entrapment.

Warning Signs

The warning signs (at right) must
be installed on both sides of the
gate (see page 7 for details).

6

!

Warning signs (2 enclosed) to be installed on each side
of the gate (3—5 feet above the bottom of the gate)

Maximum Gate: 500 lb. (226.7 kg); 16 ft. (4.8 m)
Voltage: 12 Vdc; Frequency: 0 Hz; Power: 25 W
Class I, II, III and IV 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 or rear mount from gate bracket.

3. Pull opener away from front or rear mount.

DC SWING SERIES / 500

GTO, Inc. Tallahassee, Florida USA

Disconnect operator ONLY when the control box power
switch is OFF and the gate is NOT moving.

L

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500

UL325 SERIES

®

®

E-Z GATE OPENER

Product identification and manual operation instruction
label (1) installed on control box cover

Logo and warning labels (2) installed on each side of
opener housing

C

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.

7

Single Gate Opener Parts List

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E-Z GATE OPENER

500

E-Z GATE OPENER

Opener and Mounting Hardware

8

Single Gate Opener Parts List (continued)

Transformer (1)

Battery (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)

Control Box and Electrical Components

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

• Small (Flat Bladed) Screwdriver

• Phillips Screwdriver

• Tape Measure

• Level

• Wire Strippers

• C-Clamps — small, medium, and large

• Center Punch

• Extra person will be helpful

YOU MAY ALSO NEED THESE ITEMS BEFORE YOU BEGIN THE INSTALLATION
(Some of these items can be found in the Accessory Catalog page 37):

• Low voltage wire will be needed to run from the transformer to the control box; length depends upon the distance between
the transformer power supply and the control box. See Powering the System on page 19, 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® 5 watt
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.

• PVC conduit.

• 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.

• Surge protection for transformer.

• Some types of installations require U-Bolts.

• If the gate is a push-to-open refer to page 36

• Additional washer or a metal plate may be needeed for wooden post.

9

Technical Specifications

Gate Weight

Gate Length

Number of Cycles Per Day

Mighty Mule 500 Gate Capacity /Cycle Chart

Estimated number of daily cycles, based on use with a transformer and one(1) 12 Volt battery.

850 lbs.
750 lbs.
650 lbs.
550 lbs.
450 lbs.
350 lbs.
250 lbs.
150 lbs.
100 lbs.

50 lbs.

135
145
155
165
175
185
195
205
215
225

5’ - 6’

125
135
145
155
165
175
185
195
205
215

8’

125
135
145
155
165
175
185
195
205

10’

125
135
145
155
165
175
185
195

12’

125
135
145
155
165
175
185

14’

125
135
145
155
165
175

16’

NR
NR
NR
NR

NR
125
135
145
155
165

18’

NR
NR
NR
NR

NR
NR
NR

NR
NR

NR

MIGHTY MULE® 500 E-Z GATE OPENER

DRIVE

• Low friction screw drive (linear actuator) rated for -5 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 260 rpm. Generates

680 ft. lb. of torque at 12 V.

• Maximum opening arc of 110º. Approximate opening time (90º): 20 seconds, depending on weight of gate.

POWER

• The system is powered by a 12 Vdc, 7.0 Ah, sealed, rechargeable lead acid battery.

• Battery charge is maintained by a 120 Vac input, 18 Vac output transformer rectied to 14.5 Vdc (40 VA) through the

GTO control board. One (1) blade-style control board fuse is rated for 25 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 a GTO Solar Panel Charger: float voltage of 14.5 Vdc output is from a 19

silicon alloy panel. Generates a 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.

• A circuit 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.

1

• Opener length with push-pull tube fully retracted is 40

/

4", mounting point to mounting point.

• Adjustable auto-close timer, and obstruction sensitivity.

• Power terminal block accommodates a transformer or solar panels.

• DIP switches simplify setup of gate opener.

• Accessory terminal block is 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.

3

/

8" x 8

1

/

2"

OPERATIONAL CAPACITY

• The Gate Capacity Chart shows approximate cycles, per day, you can expect from the Mighty Mule 500 Automatic

Gate Operator when powered with a transformer. Actual cycles may vary slightly depending upon the type and condi­tion of gate and installation.

NOTE: "NR" indicates this
size and weight combination
is not recommended for the
Mighty Mule 500.

IMPORTANT: BALL BEAR­ING HINGES SHOULD
BE USED ON ALL GATES
WEIGHING OVER 250 Lbs.

To determine the number of cycles the gate opener will perform using solar panels, please see the specifications

listed on page 19 or call [phone] or [phone] for more information.

* An operation cycle is one full opening and closing of the gate.

These specifications are subject to change without notice.

10

Installation Overview

Horizontal Cross Member

Vertical Cross Member

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

500

500

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 36 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
bracket (see Accessory Catalog) to properly configure your system. See Push to Open Installation on page 30 before
proceeding.

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 minimize twist or flex when the
opener is activated. We recommend you 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.

11

Installation of Mounting Hardware

Post 
Bracket

Post 
Pivot Bracket

Metal Plate

Wooden Post

Post
Bracket

Post
Pivot Bracket

Metal Plate

Wooden Post

Center of Gate Hinge

Pull-to-Open Installation

Larger than 6" diameter post

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)

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 (minimum 2 inches for safety reasons).

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.

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.

Recommended Reinforcement Examples

12

Clevis Pin

Hairpin Clip

Post Bracket Assembly

Bushing

Rear Mount

Opener

Clevis Pin

Hairpin Clip

Bushing

Gate Bracket

Front Mount

Determining the Mounting Position

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

of the Post Bracket Assembly and the Gate Bracket

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" lock

3

washer,
on the end of the bolt. DO NOT
overtighten the nut because the
post pivot bracket will have to be

/8" washer and 3/8" nut

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 30.

adjusted later.

Step 4

Attach post bracket assembly and gate bracket to the opener with the clevis pins and bushings. Secure the clevis pins with
hairpin clips.

Step 5

With the gate in the open position (up to 110º from its closed position), and the opener fully retracted, 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.

13

Gate in the

CLOSED POSITION

Pinch Area

Gate in the
OPENED POSITION

Pinch Area

2" minimum

2" minimum

Be sure gate opener
and bracket don't bind.

IMPORTANT: While determining the mounting point for the post pivot bracket assembly, be sure that the position allows

for a minimum of 2 inches of clearance between the gate and the opener in both the open and closed positions, as shown in
the diagrams below. This clearance will give the opener the most efficient leverage point for opening and closing the gate and
more importantly provides the least possible pinch area.

Step 6

When you feel that you have the best position for the post pivot bracket in the open position, insert the 5/16" x 1-3/4" bolt
through the aligned holes of the post bracket and post pivot bracket to hold it in place. Remove the clevis pin from the front
mount and while supporting the gate opener, swing the gate and gate opener to the closed position. With the gate and gate
opener in the closed position, check the clearance and be sure that the gate opener is not binding at the post pivot bracket.

If you don't have 2 inches of clearance or the gate opener is binding on the post pivot bracket, remove the 5/16" x 1-3/4" bolt

and readjust the pivot bracket until you can achieve these important clearances.

With the post pivot bracket in the optimum position for clearance and freedom of movement, reattach the opener to the gate
bracket in the open position and recheck the gate opener level and make sure the brackets are clamped securely.

TIP: Turning the pivot bracket over gives

more hole alignment options for the post
pivot bracket assembly. You can also move
the entire post pivot bracket assembly to
different positions on the gate post to help
achieve the proper clearances.

14

Installing the Post Bracket Assembly and Gate

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

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

Post Bracket
Assembly

Mark fence post through 
middle of bracket slots
and drill 3/8" holes

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

15

Mounting the Opener

Level Opener

Gate In Open Position 


LEVEL horizontal cross member

Post Bracket Assembly
bolted to fence post

Clevis Pin, Bushing, and Hairpin Clip

Clevis Pin, Bushing, and Hairpin Clip

Gate Bracket bolted
to gate cross member

Fence Post

Closed Position 
Stop Plate

Closed Position Stop Plate mounted 
on metal post with U-bolts.

Gate Hinge

The gate can open

up to 110º (max.)

Fence Post

Gate Post

TOP VIEW

SIDE VIEW

Step 11

Attach the opener to the securely bolted post bracket assembly and gate bracket using clevis pins, bushings, 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 Closed Position Stop

The Mighty Mule® Gate Opener firmly holds the gate in the closed position using the positive stop plate. The
positive stop helps stabilize the gate leaf in the closed position. To further enhance the stability and security of
your gate, install the optional Mighty Mule® Automatic Gate Lock (see Accessory Catalog).

Step 12

Remove hairpin, clevis pin, and bushing 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.

16

At this stage of the installation, the opener should be installed on the

Use mounting
holes and screws
provided to mount
control box to a
secure surface.

Horizontal Cross Member

Gate Swings Evenly and Freely
Hung Firmly and Plumb

Post Bracket Assembly

Gate Bracket

Single Gate Opener

Fence Post Set in Concrete

Closed Position Positive Stop Plate

500

gate and the closed position stop should be in place.

Check List

• The gate is plumb, level, and swings smoothly on its hinges.

• A plate or support was added for the gate bracket (if necessary).

• The opener is level and mounted on the centerline of the gate.

Mounting the Control Box

Step 13

Mount the control box using the screws (provided) or another
secure mounting method. The control box must be mounted at
least 3 feet above the ground to protect it from rain splash, snow,
etc., and at least 3 feet from an AC power source to prevent

electrical interference.

NOTE: The battery that came with your Mighty

Mule®, MUST be placed in the top (horizontal)
battery slot with the terminals on the RIGHT. The
extra (vertical) battery slot is for an optional second
battery. An optional second battery can be used for
solar and/or high traffic applications, if needed..

17

Power Cable from the Operator

RECEIVER

SWITCH

MASTER INPUTS

GRN WHT BLUE BRN ORG RED BLK COM COM

CYCLE
CLOSE

SAFETY

EXIT/
OPEN

SHADOW
LOOP

CLOSE
EDGE

OPEN
EDGE

BLKGRN RED

STALL FORCE

M

I

N

M

A

X

Correct

Wrong Wrong

Wire

Terminal �
Block

Terminal �
Block

Terminal �
Block

Wire Wire

Connecting Opener Power Cable

Sealing Nut

Hub

Lock Nut

Strain Relief

RED wire to POSITIVE (+) terminal

BLACK wire to NEGATIVE (–) terminal

RED

BLACK

Operator Power Cable

Strain Relief

Battery wires for
optional second battery.

12 Volt Battery
(included)

Space for optional
second 12 Volt battery
(see Accessory Catalog)

Step 14

Make sure the control box power switch is in the OFF position.
The ON/OFF Switch is located on the bottom of the control
box. Remove the control box cover and slide the battery into
position with its terminals to the RIGHT (see illustration).
Connect the BLACK battery wire to the NEGATIVE (–) battery
terminal. Connect the RED battery wire to the POSITIVE (+)
terminal. Pay close attention to the color of the wires. If the wires

are connected incorrectly, the control board will be damaged.

NEVER insert the battery with the terminals to the left.

Step 15

Strip approximately 3/16" of insulation from each wire of
the opener power cable. Twist each exposed wire tightly
(there are seven [7] wires inside the power cable sheath).
Loosen sealing nut on strain relief hub at bottom of
control box. Insert power cable into control box through
strain relief. Thread approximately 6" of the power cable
into the control box and retighten sealing nut until the
power cable locks into place.

Step 16

Insert the stripped power cable wires into the
appropriate terminals on the OPENER terminal
block. The green wire should be inserted into the
GRN terminal, the blue wire into BLU, the orange
wire into ORG, black wire into BLK, and the red
wire into the RED terminal, white wire into WHT,
and brown wire into BRN.

Tighten the set screws against the end of the wires.
A dab of petroleum jelly on each terminal will help
prevent corrosion.

18

Powering the System

ON/OFF Switch

Installation of the Transformer

IMPORTANT:

• The transformer is designed and intended for indoor use. If the transformer can be plugged only into
an outside electrical outlet, a weatherproof cover or housing (available at local electrical supply stores)
must be used.

• All low voltage wire used with the Mighty Mule® Gate Opener must be 16 gauge dual conductor,

multi-stranded, direct burial wire (see page 20 and the Accessory Catalog). Do not run more than

1000 feet of wire.

• If your gate is more than 1000 ft. from an ac power source, you will need to use at least one 5 watt

Solar Panel to charge the battery (see Accessory Catalog). Refer to the Solar Panels and Gate
Activity chart below.

Optional Solar Panels and Gate Activity

The table and map
illustrate the maximum
number of gate cycles
to expect per day in a
particular area when
using from 5 to 30 watts
of solar charging power.
(see Accessory Catalog).
The figures shown are

for winter (minimum
sunlight) and do not account for the use of any
accessory items. Accessories connected to

your system will draw additional power from
the battery.

NOTE: A maximum of 30 watts of solar
charging power can be connected to the
Mighty Mule® Gate Opener. Consult Solar

Panel Installation Instructions for further
information.

Winter Ratings Zone 1 Zone 2 Zone 3

12 v single gate (5 watts) solar charger 4 8 13
12 v single gate (10 watts) solar charger 8 16 26
12 v single gate (15 watts) solar charger 11 20 30
12 v single gate (20 watts) solar charger 14 28 38
12 v single gate (25 watts) solar charger 17 36 46
12 v single gate (30 watts) solar charger 20 44 54

Step 1

Make sure the power switch is OFF before proceeding to the next step.

Step 2

Select the electrical outlet iwhere you will plug the transformer.
Measure the distance from this outlet to the control box following the
path where the wire will be laid. After you have measured how much
wire is needed, cut the wire to the appropriate length.

19

IMPORTANT INFORMATION ABOUT LOW VOLTAGE WIRE

RED

BLACK

RED

BLACK

Power Cable
from First Operator

Low Voltage Wire
from AC Transformer

18VAC

SWITCH

SOLAR RELAY OUT SLAVE INPUTS

GRN WHT BLUE BRN ORG RED BLKNC RLY-COM NO

MASTER INPUTS

GRN WHT BLUE BRN ORG RED BLK

+–~~

Low Voltage Wire
from Transformer

Power Cable from
Opener Arm

PVC Pipe

The only wire acceptable for use with GTO products is 16 gauge multi-stranded, low voltage, PVC
sheathed wire. This particular gauge enables the transformer to provide an adequate charge through the
control board to the battery at distances up to 1000 ft.

DO NOT use telephone wire or solid core wire. Unlike multi-stranded wire, these types of wire are

inadequate for use with your gate opener system. Telephone wire and solid core wire do not deliver
enough voltage for your gate opener to function and will cause the system to go into a condition known
as "low voltage lockout."

NEVER splice wires together. Splicing permits corrosion and seriously degrades the wire's ability to

carry an adequate current.

Step 3

Lay the measured length of low voltage wire in a trench following a path from
the selected electrical outlet to the control box. Wires coming up from the
ground should be run through PVC conduit to protect them from lawn mower
blades, weed eaters, and grazing animals. Be sure to bury the wire laid in the
trench.

Step 4

Feed the low voltage wires upward through the strain relief opening on the
lower left of the control box. Pull 6" to 8" of wire into the control box and
tighten the strain relief screw to secure the wires.

WARNING! DO NOT PLUG THE TRANSFORMER
INTO AN OUTLET DURING THIS STEP! THE
TRANSFORMER MUST ONLY BE PLUGGED INTO
AN OUTLET DURING STEP 7!

Step 5

Strip 3/16" off the ends of the low voltage wire
and twist tightly. Attach these ends to the 18VAC
terminals located on the POWER IN terminal block
(see illustration at right). Be certain not to let the

exposed wires touch each other!

Insert one transformer wire into an 18VAC terminal.
Insert the other transformer wire into the remaining
18VAC terminal. The transformer wires can be
connected to the 18VAC terminals regardless of color.

Tighten set screws against exposed end of wires. A
dab of household petroleum jelly on each terminal will
help prevent corrosion.

20

Step 6

SURGE PROTECTOR

Transformer

1

Strip

/2" of insulation from the ends of the low voltage

wire. Attach these stripped ends to the transformer
terminals.

A dab of household petroleum jelly on each terminal will
help prevent corrosion.

Make sure the exposed wires do not touch each other!

Step 7

Plug the transformer into the electrical outlet.
(Use of a surge protector with the transformer is strongly
recommended.)

HINT: Keep a few mothballs in the control box to
discourage insects from entering it and damaging the
control board.

21

1ON234567

ON

OFF

1 2 3 4 5 6 7

DIP#6 DIP#7 Delay Time for Auto-Close

ON ON 15 seconds
ON OFF 30 seconds
OFF ON 60 seconds
OFF* OFF* 120 seconds (factory preset)

DIP#5
ON

D1 mode, constant pressure to operate gate.

OFF*

B2 mode, momentary contact to operate gate.

DIP#4
ON Push-to-open operation.
OFF* Pull-to-open operation.

DIP#3
ON Auto-close enabled.
OFF* Auto-close disabled.

DIP#2
ON* Buzzer warning enabled.
OFFBuzzer warning disabled

(for auto-close and soft start/stop only).

DIP#1
ON* Soft start enabled.
OFF Soft start disabled.

* Factory preset.

CONTROL BOARD SETTINGS

DIP Switches

Main DIP Switch Settings (MODES)

DIP Switch #1 - Soft Start/Stop

The Soft Start/Stop feature slowly starts the

gate as it begins to open and slows the gate as
it comes to the closed position. This saves wear
and tear on the gate and gate opener system.

DIP Switch #2 - Warning Buzzer

The Warning Buzzer alerts you when the gate

opener is beginning to either open or close
the gate. It sounds for the first 2 seconds in
each direction. It also sounds a warning when
the gate obstructs two times in one cycle.
Switching this to OFF only disables the open
and close warning not the obstruction warning.

DIP Switch #3 - Auto-Close

With the Auto-Close switch in the OFF position

the gate will remain open until it receives
another signal from an activation device such
as a transmitter, keypad, or push button control.
With the Auto-Close switch in the ON position
the gate opener will automatically close the
gate. The time the gate will remain open is
determined using DIP Switches #6 and #7.

DIP Switch #4 - Push/Pull-to-Open

If your gate opens into the property the DIP

DIP Switch #5 - B2/D1 Mode

This DIP Switch must remain in the OFF

DIP Switches #6 and #7

The combination of these two switches

Switch is set to the OFF position (factory
setting). If your gate opens out from the
property the DIP Switch must be set to the ON
position. NOTE: if you have a Push-to-Open
gate application you will need a Push-to-Open
bracket (see Push-to-Open Instructions on page

30).

position unless the gate opener is going to be
used by a guard or gate attendant, who can only
open the gate when constant pressure is applied
to a push button control device.

determines the amount of time the gate will
remain open when DIP Switch #3 is set to the
ON position.

IMPORTANT CONTROL BOARD SETTINGS:

CONTROL BOARD DIP SWITCH #1 is factory

preset in the ON position and MUST remain in the
ON position. Changing this setting can damage
your gate, gate opener and
possibly void your warranty!

22

Setting the Closed Position Limit

1

ON

2 3 4 5 6 7

RECEIVER

SET

LIMIT

LEARN

TRANSMITTER

MODES

ON

OFF

1 2 3 4 5 6 7

COM

CYCLE
CLOSE

SAFETY

EXIT/
OPEN

SHADOW
LOOP

CLOSE
EDGE

OPEN
EDGE

BLKGRN RED

Set Limit Button

STALL FORCE

M

I

N

M

A

X

TURN CONTROL BOX ON

Your Mighty Mule® has two Limit Settings

1) OPEN Limit setting: (Gate in the OPEN POSITION / the limit is FACTORY SET and NOT ADJUSTABLE) The open
limit setting is the fully open position.

2) CLOSED Limit setting: (Gate in the CLOSED POSITION) To achieve optimum closed position, you are required
to complete the following FOUR STEPS:

Step 1

Confirm that the power switch is in the ON position and the gate is in the OPEN POSITION.

Step 2

Activate your opener by pressing the entry transmitter button. Your gate should now be moving from the fully open position
toward the closed position. Prepare to STOP the gate by
pressing the entry transmitter button again when the gate
reaches the desired closed position. This step may be repeated
until desired close position is achieved. Once the desired
CLOSED position has been achieved, proceed to step 3.

Step 3

With the gate in the desired closed position PRESS & HOLD

the “SET LIMIT" button on the control board for 5 seconds.

Step 4

Press the transmitter button and allow the gate to return to the
fully open position. YOUR GATE’S CLOSED POSITION
LIMIT IS NOW PROGRAMMED.

TESTING YOUR CLOSED LIMIT SETTING:

Press your entry transmitter and allow your gate to close. If the CLOSED position is not correct or needs to be changed, you
will need to CLEAR your CLOSED LIMIT settings and follow Steps 1-4 again.

CLEARING THE PROGRAMMED CLOSED LIMIT SETTING:

If you make a mistake and set the limit at the wrong position – press your transmitter to return the gate to the fully opened
position, then press and hold the "SET LIMIT" button for 10 seconds. This will clear the memory for the closed limit
position. Follow Steps 1-4 again.

23

Obstruction Sensitivity Potentiometer

STALL FORCE

M

I

N

M

A

X

IMPORTANT: For safety reasons the obstruction setting or Stall Force
on the Mighty Mule® control board comes from the factory set at MIN
(minimum). In many gate installations this setting will need to be adjusted
to overcome the weight and size of the gates.

The Stall Force potentiometer on the control board operates like a volume
control on a radio. It controls the obstruction sensitivity (or the amount of
force the opener will apply to an obstruction)
before it automatically stops and reverses
direction for approximately two (2) seconds.

Use a small slotted screwdriver to turn the ar­row in the center of the potentiometer. Adjust
the sensitivity from the MINIMUM position
where the gate operates without obstructing
from its own weight or the wind conditions in
your area.

NOTE: You may need to increase the
stall force in cold weather due to increased
resistance from gate hinges.

ALWAYS KEEP SAFETY AT THE TOP OF YOUR LIST WHEN ADJUSTING OR

SERVICING YOUR AUTOMATIC GATE OPENER!

24

1 2 3 4 5 6 7 8 9

ECE

A23S 12V

ALKALINE BATTERY

+

0

–

LED

Setting Your Personal Transmitter Code

1

ON

2 3 4 5 6 7

RECEIVER

SET

LIMIT

LEARN

TRANSMITTER

MODES

ON

OFF

1 2 3 4 5 6 7

COM

CYCLE
CLOSE

SAFETY

EXIT/
OPEN

SHADOW
LOOP

CLOSE
EDGE

OPEN
EDGE

BLKGRN RED

Learn Transmitter Button

STALL FORCE

M

I

N

M

A

X

+

0

ECE

1 2 3 4 5 6 7 8 9

All GTO transmitters are set to a standard code at the factory and are ready to operate your Mighty Mule® Gate Opener
For your safety and security, however, we strongly recommend that you replace the factory setting with your own personal
code. Follow the directions below:

1. Remove the Transmitter Cover

On the back of the transmitter use a small phillips head screw driver to remove
the two screws on the sides of the visor clip and separate the front cover from the
transmitter. With the front cover removed, the battery and the DIP switches will
be exposed. To set a new code, use a small screwdriver to move the switches.

2. Set the transmitter DIP Switches

There are nine (9) transmitter DIP switches; each can be placed in three different
positions (+, 0, –). DO NOT set all the switches in the same position, such as all +,
all 0, or all –. Once the DIP switches have been set to a personal code, replace front
cover.

WARNING: No other adjustments should be made inside the transmitter.

®

.

3. “Teach” the New Code to Control Board Memory

A. Press and hold transmitter button.
B. Press and hold the LEARN TRANSMITTER button on
the control board for 5 seconds.
C. Release LEARN TRANSMITTER button.
D. Release transmitter button. The new code
is stored in control board memory.

25

Installing the Receiver

Use the transmitter to check the range of the receiver before permanently mounting it.

Consider the following when mounting the receiver:

• Standard receiver cable length is 10 feet (receivers with a longer cable are available as

special order items; call the GTO Sales Department). NEVER splice receiver cable!

• Run the cable through PVC conduit to protect it from damage.

• DO NOT run cable through metal conduit because the receiver signal range will be

decreased.

• DO NOT run cable in conduit containing ac wiring.

• The receiver range can vary from 50 to 100 feet depending upon weather, topography,

and external interference.

NOTE: Do not mount upside down.

FCC Regulation

This device complies with FCC rules Part 15. Operation is subject to the following
conditions:

1. This device may not cause harmful interference.

2. This device must accept an interference that may cause undesired operation.

Transmitter distance may vary due to circumstances beyond our control. NOTE:

The manufacturer is not responsible for any radio or TV interference caused by
unauthorized modifications to this equipment. Such modifications could void the
user’s authority to operate the equipment.

26

Connecting Additional Safety Devices

Wire from Contact Sensor
(open safety edge)

Wire from Contact Sensor
(close safety edge)

RECEIVER

COM COM

CYCLE

CLOSE

SAFETY

EXIT/

OPEN

SHADOW

LOOP

CLOSE

EDGE

OPEN

EDGE

BLKGRN RED

STALL FORCE

M

I

N

M

A

X

Although GTO strongly recommends the use of additional safety devices, we do not endorse any

specific brand names. Only use products that are certified and listed to be in compliance with

any applicable UL standards (United Laboratories) and national and regional safety codes.

Call GTO Sales at 1-800-543-4283 for information on compatible

products for your specific application.

The Mighty Mule® 500 will ONLY accept accessory devices with normally open dry contact output.

Contact Sensors (safety edges)

If not installing a contact sensor skip to next section.

PLEASE NOTE: Contact sensors are not included with the Mighty Mule® 500.

The Mighty Mule® 500 is equipped with built-in obstruction sensitivity. The opener is designed to stop and reverse the

gate within 2 seconds when it comes in contact with an obstruction. However, obstruction sensitivity, although functioning

properly, may not be sensitive enough to prevent bodily injury in some circumstances. To augment your protection against
entrapment, GTO recommends using some form of additional safety device. When installed, contact sensors must be
mounted in compliance with UL 325, Underwriters Laboratories safety standard for gate openers. Review page 5 for infor­mation about mounting requirements for safety edges ("contact sensors").

Refer to the sensor manufacturer’s instructions for
information about installing these devices on a vehicular
gate.

Make sure the power switch to the opener is
turned off before connecting safety device
wiring to the terminal blocks. Unplugging the
transformer does not turn power to the opener
OFF.

Contact Sensor Input Connection:

Connect one of the OPEN EDGE contact sensor wires to the

COMMON (COM) terminal and the other to the OPEN
EDGE terminal on the Mighty Mule® 500 control board.

Connect one of the CLOSE EDGE contact sensor wires to the

COMMON (COM) terminal and the other to the CLOSE
EDGE terminal on the Mighty Mule® 500 control board.

Activation of a contact sensor while the gate is in motion
will cause the gate to stop and reverse within two (2)
seconds.

27

Non-Contact Sensors (photo beams)

Wire from Non-Contact
Sensor (photo beam)

RECEIVER

COM COM

CYCLE

CLOSE

SAFETY

EXIT/

OPEN

SHADOW

LOOP

CLOSE

EDGE

OPEN

EDGE

BLKGRN RED

STALL FORCE

M

I

N

M

A

X

Wire from Shadow Loop

RECEIVER

COM COM

CYCLE

CLOSE

SAFETY

EXIT/

OPEN

SHADOW

LOOP

CLOSE

EDGE

OPEN

EDGE

BLKGRN RED

STALL FORCE

M

I

N

M

A

X

If not installing a non-contact sensor skip to next section.

PLEASE NOTE: Non-contact sensors are not included with the Mighty Mule® 500.

The Mighty Mule® 500 can also accept "Safety" input from normally open "dry-contact" output devices such as photo beams
connected to the SAFETY input terminal.

Refer to the sensor manufacturer’s instructions for information
about installing these devices on a vehicular gate.

Make sure the power switch to the opener is turned
off before connecting safety device wiring to the
terminal blocks. Unplugging the transformer does
not turn power to the opener OFF.

Non-Contact Sensor Connection:

Connect one of the non-contact sensor dry contact output wires to
the COMMON (COM) terminal and the other to the SAFETY
terminal on the Mighty Mule® 500 control board.

This input is ONLY monitored when the gate
is closing. Activating the non-contact sensor
(obstructing the safety beam path) will cause the
gate to reverse to the fully open position.

Shadow Loop

If not installing a shadow loop skip to next section.

PLEASE NOTE: Non-contact sensors are not included with the Mighty Mule® 500.

Refer to the sensor manufacturer’s instructions for information
about installing these devices on a vehicular gate.

Make sure the power switch to the opener is turned
off before connecting safety device wiring to the
terminal blocks. Unplugging the transformer does
not turn power to the opener OFF.

Shadow Loop Connection:

Connect one of the shadow loop wires to the COMMON (COM)
terminal and the other to the SHADOW LOOP terminal on the
Mighty Mule® 500 control board.

The SHADOW LOOP is a detector located within the moving
path of the gate to prevent the gate from closing when a vehicle is
in the path.

28

Connecting Accessories

OPEN STOP CLOSE STOP

Wire from Accessory
(push button, key pad, etc.)

RECEIVER

COM COM

CYCLE

CLOSE

SAFETY

EXIT/

OPEN

SHADOW

LOOP

CLOSE

EDGE

OPEN

EDGE

BLKGRN RED

STALL FORCE

M

I

N

M

A

X

If not connecting accessories skip to next section.

The Mighty Mule® 500 can accept NORMALLY OPEN CONTACT accessories, such as; Push Button Entry Devices
and Key Pads.

Refer to the sensor manufacturer’s instructions for information about installing these devices on a vehicular gate.

Make sure the power to the opener is turned
off before connecting safety device wiring to the
terminal blocks. Unplugging the transformer
does not turn power to the opener OFF.

Accessory Input Connection:

Connect one of the accessory wires to the COMMON
(COM) terminal and the other to the CYCLE CLOSE

terminal on the Mighty Mule® 500 control board.

Each activation of the accessory will cause the
gate to cycle as follows:

29

Gate in the Closed Position

Pinch Area (gray)

Gate in the Open Position

Pinch Area (gray)

2" minimum

2" minimum

Push to Open Installation

3/8" x 2" Bolt

3/8" Nut

Push-To-Open Bracket
(optional accessory)

Post Bracket

Post Bracket

3/8" Lock Washer

Post Bracket Assembly

3/8" Washer

Determining The Mounting Position
of The Post Bracket Assembly

Swinging gates shall not open into public access areas!

A "Push-to-Open" gate opens out from the property.

A Push-to-Open Bracket is required for this type of installation (see
Accessory Catalog). If you have a pull-to-open gate (gate opens into the

property), return to page 13; step 3.

In a PUSH-TO-OPEN installation, the openers are installed while the gates

are in the closed position.

Step 1

With the gates closed, adjust the post bracket assembly and the 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.

IMPORTANT: While determining the mounting point for the post

pivot bracket assembly, be sure that the position allows for maximum
clearance between the gate and the opener in both the open and closed
positions, as shown in the diagrams below. This clearance will give the
opener the most efficient leverage point for opening and closing the gate
and more importantly provides the least possible pinch area.

Step 2

After verifying that you have the best position
for the post pivot bracket, insert the 5/16" x 1 3/4"

bolt through the aligned holes of the post bracket
and post pivot bracket and fasten it with the 5/16"

washer and nut.

IMPORTANT: If you loosened the clamp on
the post bracket to achieve the optimum position,
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).

30

Step 3

1ON234567

ON

OFF

1 2 3 4 5 6 7

DIP#4

ON Push-to-open operation.

OFF Pull-to-open operation (factory setting).

Operator

Fence Post

Gate Post and Gate Cross Member
(In Closed Position)

POST PIVOT BRACKET level with the
horizontal surface of the GATE BRACKET

LEVEL

LEVEL

LEVEL

With the gate in the fully closed position and the opener retracted, swing the opener to the gate. Mark reference points for
bolt holes on gate cross member through middle of gate bracket slots. The opener must be level. (Some vertical adjustment

is possible by sliding the post bracket assembly up and down.) Drill 3/8" holes into the gate cross member as marked. Fasten
gate bracket to cross member using (2) 3/8" x 3" bolts, washers, lock washers, and nuts. Attach the opener to the post bracket
assembly and gate bracket using clevis pins, bushings, and hairpins clips.

Step 4

Make sure the control box power switch is OFF. Use a small
screwdriver to move the Number 4 DIP switch from the factory
setting (OFF / Pull-To-Open) to ON for Push-To-Open. Turn
power switch ON. The control board is now configured to push the
gate open.

Setting the Open Position Limit

Step 1

Confirm that the power switch is in the ON position, and the gate is in the CLOSED POSITION.

Step 2

Activate your opener by pressing the entry transmitter button. Your gate should now be moving from the closed position
toward the open position. Prepare to STOP gate by pressing the entry transmitter button again when the gate reaches the
desired open position. This step may be repeated until desired open position is achieved. Once the desired OPEN position has
been achieved, proceed to Step 3.

31

Step 3

1

ON

2 3 4 5 6 7

RECEIVER

SET

LIMIT

LEARN

TRANSMITTER

MODES

ON

OFF

1 2 3 4 5 6 7

COM

CYCLE
CLOSE

SAFETY

EXIT/
OPEN

SHADOW
LOOP

CLOSE
EDGE

OPEN
EDGE

BLKGRN RED

Set Limit Button

STALL FORCE

M

I

N

M

A

X

With the gate in the desired open position PRESS & HOLD the “SET LIMIT" button on the control board for 5 seconds.

Step 4

Press the transmitter button and allow the gate to return to the
closed position. YOUR GATE’S OPEN POSITION LIMIT IS
NOW PROGRAMMED.

TESTING YOUR OPEN LIMIT SETTING:

Press your entry transmitter and allow your gate to open. If the
OPEN position is not correct or need to be changed, you will
need to CLEAR your OPEN LIMIT settings and follow steps
one (1) to four (4) again.

CLEARING PROGRAMMED OPEN LIMIT
SETTING:

If you make a mistake and set the limit at the wrong position
– press your transmitter to return the gate to the fully closed
position, then press and hold the "SET LIMIT" button for 10
seconds. This will clear the memory for the open limit position.
Follow steps one (1) to four (4) again.

32

Maintenance & Troubleshooting Guide

If your gate opener does not function properly after it is installed, use this guide before calling the GTO Service Department.

• On all gates weighing 250 lb. or more, routinely grease the ball bearing hinges at least 4 times a year; more
frequently if the gates are near a coastal area.

• Keeping a few mothballs in the control box will discourage insects from entering it and damaging the control

board.

• Clean the push-pull tube with a soft, dry cloth and apply silicone spray to it at least once per month.

• While oxidation is a normal part of weathering of equipment that is exposed to the elements, we recommend

you apply silicone spray the front and rear mounts to minimize this effect.

If the Opener Does Not Work

Check the Green LED on the Control Board:

IF THE LED IS OFF: This condition indicates a transformer power failure.

1. Test the transformer for voltage with a voltmeter. The acceptable range can be found in the VOLTAGE
LIMITS chart on the next page. If the transformer test shows no voltage, then test the electrical outlet for

voltage. If the outlet test shows voltage, then the transformer is dead and must be replaced. Allow the new
transformer 12 hours to charge the battery before using the gate opener.

2. If the transformer test shows voltage, check the POWER IN terminal block on the control board for voltage.
If the terminal block shows no voltage, look for broken or spliced wires.

Check the Red LED on the Control Board:

IF THE LED IS ON: but the unit is not working.

1. Check the battery in your transmitter and replace with a fresh one if needed..

2. Verify that the power cable is securely connected.

3. Replace the control board fuse if it is blown (15 ampere fuse only - DO NOT USE

A HIGHER RATED FUSE!).

IF THE LED IS OFF:

1. Make sure the ON / OFF switch at the bottom of the control box is set to ON.

2. Check all connections for looseness and corrosion.

33

If the Opener is Working

The Gate CLOSES Then Opens Again on its Own:

1. Check the position of the mounting brackets and readjust if necessary.

2. Check the gate for binding or hinge damage.

The Gate OPENS Then Closes Again on its Own:

1. Check the position of the mounting brackets and readjust if necessary.

2. Check the gate for binding or hinge damage.

VOLTAGE RATINGS

18 Vac Transformer ___________________________ 18.0 to 22.0 Vac

5 W Solar panel (single) _______________________18.0 to 22.0 Vdc 300 mA
measure voltage at panel and control box.

12 V Battery ________________________________12.0 to 13.5 Vdc 7.0 Ah

Charging circuit _____________________________12.0 to 14.8 Vdc
measure voltage with battery connected

The GTO, Inc. Technical Service Department is open

Monday – Friday 8:00 A.M. – 5:00 P.M. (Eastern Time)

Telephone [phone]
Telephone [phone]

Fax [phone] • Web site: www.mightymule.com

E-Mail: [e-mail]

34

Repair Service

®

E-Z GATE OPENERS

If your Mighty Mule® Gate Opener is not operating properly, please follow the steps below:

1. First use the procedures found in the Maintenance & Troubleshooting Guide (see page 33).

2. If you are unable to solve the problem, call the GTO Service Department at [phone], or [phone].
Refer to the serial number (located on the control box cover) and date of purchase when calling for assistance.

3. If repair or replacement of your gate opener is necessary, the Service Department will assign a Return Goods
Authorization (RGA) number to you for warranty repair.

4. Securely pack the component(s) authorized for return to the factory. Write the RGA number issued to you on the outside
of the package in LARGE BOLD PRINT. Ship the package(s) freight prepaid to:
GTO, Inc., 3121 Hartsfield Road, Tallahassee, Florida, USA 32303.

NOTE: Products returned to GTO without a Return Goods Authorization (RGA) number in LARGE
BOLD PRINT on the outside of the package WILL NOT be accepted. Also, items returned to GTO freight
collect WILL NOT be accepted.

For technical service Call toll free:

3121 Hartsfield Road • Tallahassee, Florida, USA 32303 • [phone] • Fax [phone] • Web site www.mightymule.com

For sales call toll free:

1-800-543-GATE (4283)

1-800-543-1236

GTO, Inc.

35

Column Installation Information

Column

Pivot Bracket

Gate

A

B

Column Mount Example
(A + B can not exceed 14 inches)
Example: If A is 2" then B can not exceed 12"

Hinge

IF THIS OPENER WILL BE USED WITH GATES THAT ARE MOUNTED ON

MASONRY, BRICK, OR ROCK (etc.) COLUMNS:

READ THE FOLLOWING CAREFULLY BEFORE PROCEEDING

A. The simplest solution is to install the opener in a push-to-open configuration (requires Push-To-Open Bracket,

see Accessory Catalog). The minimum clearance is easier to achieve and clearance is no longer a problem,
since the opener will be pushing the gate away from the column instead of pulling it toward the column. It
is recommended that you place a steel plate between the opener mounting brackets and masonry surface for
additional strength.

B. If a push-to-open installation is impossible due to traffic hazards, terrain, etc., another option is to re-hang the

gate. You may hang it on a post, either in the center of the column or at the back corner, or move the gate to the
back corner of the columns.

C. The most difficult solution is to cut a notch in the column to accommodate the opener and power cable. This

job is NOT for the inexperienced!

36

AUTOMATIC
GATE LOC K

®

E-Z GATE OPENERS

ACCESSORIES

1

2

3

4

5

6

7

8

9

0

Accessories are Available From Your Retail Store

Solar Panel (FM121) Not Compatible with Mighty Mule® 250

The Solar Panel is a 5 watt solar powered battery charger for use with the FM500 & FM502 gate opener systems.
Particularly suited for remote installations, each Solar Panel comes with tubular steel support, mounting clips, wire
connectors, and 8 ft. of low voltage wire (see Low Voltage Wire for additional wire). The Mighty Mule® control board
has clearly labeled terminal connections for easy installation of the Solar Panel. Installation in some regions of the
world will require multiple solar panels for adequate charging power. Dual gates require a minimum of 10 watts of
solar charging power. (10 watt solar panels are available)

Push Button (doorbell) Control (FM132)

Unlit doorbell button for remote entry or exit control. Wires directly to the control board and uses 16 gauge multi­stranded, dual conductor low voltage wire (sold separately).

Pin Lock (FM133)

The Pin Lock substitutes for the clevis pin at the front end of the Mighty Mule® gate openers. Helps prevent theft of
the opener from the gate, while allowing quick release of the opener.

Key Chain Mini Transmitter (FM134)

The Key Chain Mini Transmitter is a miniature version of the Mighty Mule® entry transmitter and has the same
adjustable code settings. 12 Volt battery included.

Entry Transmitter (FM135)

The Mighty Mule® entry transmitter, with adjustable code settings, is standard equipment with all Mighty Mule®
systems. 9 Volt battery included.

Digital Keypad (FM137)

The specially designed digital keypad can be easily installed as a wireless or wired keypad. It can be programmed to
use up to 25 different personal identification number (PIN) codes. Each code is face programmable with additional
security features built in. Wired installations require 16 gauge, low voltage, multi-stranded, dual conductor, direct

burial wire (sold separately). Requires 3 AA batteries (not included).

Gate Opening Sensor (FM138) Not Compatible with Mighty Mule® 250

The Gate Opening Sensor is designed for residential and agricultural applications and is compatible with most Mighty
Mule® automatic gate opener models (see Sensor Box for model compatibility). The Sensor is an electromagnetic

sensor, which offers 'hands free' operation of the Mighty Mule® Gate Opener with a 12 ft. radius of detection of

vehicles in motion.

Automatic Gate Lock Pull-to-Open (FM143) Not Compatible with Mighty Mule® 250

A MUST for added security. Solenoid driven with a steel housing. Unlocks and locks automatically as gates open and
close. Used with the Mighty Mule® system for maximum stability and security. Comes with a keyed manual release.
Recommended for gates over 8 ft. long. Ideal for animal enclosures or high wind areas.

Wireless Entry Intercom / Keypad (FM136)

Allows owner to screen guest at the gate before allowing access to the property. Keypad also allows owner to give up to
25 programmable entry codes to family, friends or approved delivery personnel. Codes can be permanent of temporary.
Can be wireless or hard wired up to 1000 feet.

Gate Opener Light Kit with Digital Controller (FM124)

The light kit’s control board and the daylight sensor integrate the two low voltage lights with the existing gate opener,
allowing the lights to come on when the driveway gate is opened and shut off after the gate closes, at night. Lights can
be face mounted or mounted on top of the gate posts.

37

Accessories are Available From Your Retail Store (con't)

Replacement Battery (FM150) Not Compatible with Mighty Mule® 250

Standard 12 volt, 7.0 amp-hour, maintenance-free battery for the Mighty Mule® FM500 & FM502 gate opener
systems. This is the only battery approved for use with the Mighty Mule® FM500 & FM502 gate opener systems.

Life expectancy is 3-5 years.

Low Voltage Wire (RB509)

The 16 gauge, multi-stranded, dual conductor Low Voltage Wire is for connecting the AC powered transformer, or
the Solar Panel to the control board. Also used for the connection of accessories, such as locks, keypads, push buttons
and other wired control devices. This specially designed wire is UV treated, PVC coated and ready for direct burial.

Available in 1000' rolls or special lengths.

11" Push to Open Bracket (FM148) Not Compatible with Mighty Mule® 250

Required when Mighty Mule® 500/502 gate opener(s) must push the gate open, such as on a sloping driveway or
where space prevents gate(s) from opening inward (pulled open). Order two PTO brackets for conversion of a dual

swing gate installation.

Column Mount Lock Receiver (433IH) Not Compatible with Mighty Mule® 250

For mounting the Automatic Gate Lock on brick columns, walls, or for other applications with limited space
between gate and post.

Replacement Transformer (RB570)

Standard 18 volt AC transformer for maintaining the battery included with the Mighty Mule® gate opener. This is the
only transformer approved for use with all UL325 Mighty Mule® gate opener systems.

Garage Door Receiver (RB709)

The Garage Door Receiver allows you to use the same Mighty Mule® entry transmitter (see Dual and Triple
Transmitters) to operate your gate opener and your garage door opener. Compatible with most garage door openers.

Dual & Triple Button Transmitters (RB742 & RB743)

The Dual (RB742) & Triple (RB743) Button Transmitters are for remote control of multiple separate gate openers,
and/or gate opener(s) and garage door opener(s) (see Garage Door Receiver). 9 Volt battery included.

If you have a question about any special order item,

just call 1-800-543-GATE!

The contents of all material available on this installation manual are copyrighted by GTO, Inc. (“GTO”), unless otherwise indicated. All rights are reserved by GTO, and content may not be reproduced,

downloaded, disseminated, published, or transferred in any form or by any means, except with the prior, written permission of GTO. Any reprinting of GTO publications is by permission only. Copyright

Mighty Mule¨, E-Z Gate¨, GTO¨, are registered trademarks of GTO, Inc. America’s DIY Automatic Gate Openers is a trademark of GTO, Inc. and are the exclusive property of GTO, Inc. (“GTO”).

All rights are reserved by GTO, and these marks may not be used, in any for without the prior, written permission of GTO.

infringement is a violation of federal law.

38