GTO Mighty Mule 352 User manual

©2008 GTO, Inc.
R352INST
rev - 08/08/08
Installation Manual for the
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.
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.
UL325 SERIES
352
®
E-Z GATE OPENER
GTO Sales: (800) 543-GATE (4283) or [phone] • Fax [phone] or
GTO Technical Service [phone] or [phone]
For 24 hr/day, 7 day/week Technical Service visit http://support.gtoinc.com/support/troubleshooter.aspx
For more information on Mighty Mule’s full line of Automatic Gate Openers and Access Controls visit our website at 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.
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 rear of opener arm),
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
Tools and Items Needed for Installation------------------------------------------- page 9
Technical Specifications ------------------------------------------------------------- page 10
Installation Overview -------------------------------------------------------------------- page 11
Installation of the Mounting Hardware--------------------------------------------- page 12
Mounting the Master Opener --------------------------------------------------------- page 16
Mounting the Second Opener-------------------------------------------------------- page 16
Installation of the Closed Position Stops ----------------------------------------- page 16
Trench and Lay Conduit for Wiring ------------------------------------------------- page 19
Preparing To Connect The Wires ------------------------------------------ page 19
Attaching Master Battery and Communication Cables ---------------------- page 20
Attaching Second Battery and Communication Cables -------------------- page 21
Powering Options: Transformer or Solar------------------------------------------ page 22
Connecting the Battery ----------------------------------------------------------------- page 23
Connecting the Transformer ---------------------------------------------------------- page 24
Connecting Solar Panel(s)------------------------------------------------------------- page 26
Master Control Board Settings -------------------------------------------- page 26
DIP Switches ------------------------------------------------------------------------------- page 26
Dual Mode DIP Switches --------------------------------------------------------------- page 26
Stall Force and Auto-Close ------------------------------------------------------------ page 27
Installing the Receiver ----------------------------------------------------------------- page 28
Setting the Closed Position Limit ---------------------------------------------------- page 29
Setting Your Personal Transmitter Code ------------------------------- page 30
Connecting Additional Safety Devices --------------------------------- page 31
Control Board Connections ------------------------------------------------ page 32
Connecting Accessories ----------------------------------------------------- page 33
Routing Wires Through the Access Panel ----------------------------- page 34
Final Step ------------------------------------------------------------------------- page 35
Push to Open Installation ---------------------------------------------------- page 36
Setting the Open Position Limit -------------------------------------------- page 37
Visual and Audible Diagnostic Indicators ----------------------------- page 39
Repair Service ------------------------------------------------------------------ page 41
Column Installation Information ------------------------------------------ page 42
Accessory Catalog ------------------------------------------------------------ page 43
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 video and read these instructions carefully and completely
to become familiar with all parts and installation steps. The video is only designed
as an 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.
Thank you for purchasing a Mighty Mule® 352 E-Z Gate Opener—GTO's "do-it-yourself" automatic gate
opener! When correctly installed and properly used, your Mighty Mule® 352 E-Z Gate Opener will give
you many years of reliable service. Please read the following information and watch the enclosed video to
ensure you have the correct system for your particular needs. Furthermore, this manual and the video will
enable you to properly install your Mighty Mule® 352 E-Z Gate Opener.
The Mighty Mule® 352 E-Z Gate Opener is designed for installation on a pull-to-open dual gate leafs
(gates that open into the property). By purchasing an accessory bracket (FM148), the Mighty Mule®
352 E-Z Gate Opener can accommodate a push-to-open dual gate leafs (gates that open out from the
property). The gates must not exceed 8 feet and 550 pounds or exceed 16 feet and 150 pounds (please
see Technical Specifications on page 10). The Mighty Mule® 352 EZ Gate Opener can be used on vinyl,
aluminum, chain link, farm tube, and wrought iron gates.
The Mighty Mule® 352 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® 352 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® 352 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:
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.
®
E-Z GATE OPENERS
Use on solid (surface) 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, blow fuses, or may damage the equipment.

IMPORTANT SAFETY INSTRUCTIONS
Mighty Mule 352 1
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.
Disconnecting the Opener
1. Turn opener power switch OFF.
2. Remove hairpin clip, clevis pin, and
bushing from the front 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 (FM133) for the clevis pin
on the front mount only of the gate opener 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: The gate will move freely and uncontrolled when the gate
opener is removed from the gate. ONLY disconnect the opener when the
opener power switch is OFF and the gate is NOT moving.
Clevis Pin
Hairpin Clip
Gate Bracket
Front Mount
0caVW\U
CAUTION: Because the Mighty Mule gate
opener is battery powered, disconnect the opener
ONLY when the power switch on the opener is
turned OFF. Unplugging the transformer does not
turn power to the opener OFF.
IMPORTANT: NEVER allow opener arm to hang by the
front mount - it will break from the arm weight.

IMPORTANT SAFETY INSTRUCTIONS
2 Mighty Mule 352
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
Gate in the
Open Position
ZONE 2
ZONE 3
ZONE 4
ZONE 5
Driveway
ZONE 1
ZONE 2
ZONE 4
ZONE 5
ZONE 3
Entrapment Zones for a
Pull-To-Open Application

IMPORTANT SAFETY INSTRUCTIONS
Mighty Mule 352 3
Moving Gate
Area
Moving Gate
Area
Driveway
10'10'
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 master and second gate.
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.
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

IMPORTANT SAFETY INSTRUCTIONS
4 Mighty Mule 352
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 an activated 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. Grease hinges, spray push pull tube with high quality silicone spray.
7. 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.
8. Disconnect the opener ONLY when the power is TURNED OFF and the gate is NOT moving.
9. Make arrangements with local fire and law enforcement for emergency access.
10. Distribute and discuss copies of the IMPORTANT SAFETY INSTRUCTIONS section of this manual with
all persons authorized to use your gate.
11. 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.
Additional copies of this manual 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.

IMPORTANT SAFETY INSTRUCTIONS
Mighty Mule 352 5
ENTRAPMENT ALARM (UL 325; 30A.1.1A)
The Mighty Mule® 352 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.
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® 352 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.
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.
Bottom Edge Contact Sensor
on both sides of the gate
Leading Edge Contact Sensor
on both sides of the gate
Post Edge Contact Sensor
on both sides of the gate
Post Edge Contact Sensor
on both sides of the gate
Vehicular GateVehicular Gate

IMPORTANT SAFETY INSTRUCTIONS
6 Mighty Mule 352
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 enhanced 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®
352 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 SignWarning Sign Contact Sensor
(
recommended, not included
)
Contact Sensor
( recommended, not included )
Pedestrian Gate
Bulldog Pedestrian
Gate Lock
(recommended, not included )
Vehicular GateVehicular Gate
Contact Sensor
( recommended, not included )
Contact Sensor
( recommended, not included )

IMPORTANT SAFETY INSTRUCTIONS
Mighty Mule 352 7
!
Warning signs (4 enclosed) to be installed on each side
of the gate (3–5 feet above the bottom of the gate).
This label is located
under rear mount on the opener.
Logo and warning labels (2) installed on each side of
opener housing.
1-800-543-GATE (4283) • www.mightymule.com
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.
Can Cause Injury or Death
MOVING
GATE!
®
E-Z GATE OPENER
UL325 SERIES
®
352
! !
TO MANUALLY OPEN AND CLOSE THE GATE
1. Turn opener power switch OFF.
2. Disconnect front or rear mount from
mounting bracket.
3. Pull opener away from mounting bracket
and move gate.
Disconnect opener ONLY when the power
switch is OFF and the gate is not moving.
Maximum Gate: 550 lbs. (249.4 kg); 16 ft. (4.9 m) • Voltage: 12 Vdc; Frequency: 0Hz; Power: 25W • Class I, II, and III Vehicular Swing Gate Operator
GTO DC SWING Series
Conforms to UL325
5th Edition Standards
Serial No. MM350DUAL-0000000
05/14/08
GTO, Inc. - Ta llahassee, Florida USA
Product identification label
These warning labels should be
found at the locations specified
below. If any of them are
missing, immediately contact
GTO for replacements.

8 Mighty Mule 352
Parts List - Opener and Mounting Hardware
Hairpin Clip (4)
3/8" x 1-1/2" Clevis Pin (4)
5/16" x 1-3/4" Bolt (2)
3/8" x 2" Bolt (2)
3/8" x 3" Bolt (4)
3/8" x 8" Bolt (8)
8" Nylon Cable Tie (14)
3/8" Washer (18)
3/8" Lock Washer (14)
5/16" Washer (2)
3/8" Nut (14)
5/16" Nut (2)
Hardware Bag Contents
Second Opener (1)
Master Opener (1)
Post Pivot Bracket (2)
3/8" Bushings (4)
32’ Communication
Cable (1)
Gate Bracket (2)
Post Bracket (4)
Closed Position
Stop Plate (1)
2" Mounting Screw (5)
Installation Video (1)
Customer Support Card (1)
Transformer (1)
Warning Signs (4)
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’ Master
Battery
Harness (1)
GTO Transmitter (1)
32’ Second Opener
Battery Harness (1)
10’ Master
Battery Harness (1)
0
2

Mighty Mule 352 9
Tools Needed
• Center Punch
• Open End Wrenches — 3/8", 7/16", 1/2", and 9/16"
• Small (Flat Bladed) Screwdriver
• Tape Measure
• Level
• Wire Strippers
• Phillips Screwdriver/ Large
• C-Clamps — small, medium, and large
• Power Drill
• 3/8" Drill Bit
• Hacksaw or Heavy Duty Bolt Cutters
• 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 42):
• Low voltage wire (RB509) will be needed to run from the transformer to the opener control board;
length depends upon the distance between the transformer power supply and the opener arm. See
Powering Options: Transformer or Solar on page 22, and the Accessory Catalog.
• If your gate is more than 1000' away from AC power source you will need to use at least one
Mighty Mule® 10 watt Solar Panel (FM123) to charge the 12 Volt automotive or marine type battery
(not included). 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.
• Metal plate or washer between nuts and fence posts to prevent pulling bolts out of wood.
• If your fence post is larger than 6" in diameter you will need threaded rods or carriage bolts longer
than 8". See page 15.
• Low prole ground stop page 17.
• 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.
• Spade terminal for transformer page 25, step 4.

10 Mighty Mule 352
DRIVE
• Low friction screw drive (linear actuator) rated for -5 ºF to +160 ºF (-21 ºC to +71 ºC).
• Powered by a 12 V motor with integral case hardened steel gear reducer. Motor speed reduced to 260 rpm.
Generates 520 inch lb. of torque at 12 V.
• Maximum opening arc of 110º. Approximate opening time (90º): 18 seconds, depending on weight of gate.
POWER
• The system is powered by a 12 Vdc automotive or marine battery.
• Battery charge is maintained by a 120 Vac, 18 Vac output transformer [rectied to 14.5 Vdc (40 VA) through
the GTO control board] or by optional GTO Solar Panels [the panel should generate minimum of 10 W at
600 mA]. A diode on the control board prevents battery discharge.
IMPORTANT: Never use both transformer and solar panel - this will damage the battery and control board.
• One (1) blade-style control board fuse is 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.
CONTROL
•GTO microprocessor-based control board is set for dual 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 25 mA; "active draw" is 2 to 5 A.
• Auto-memorization of digital transmitter code.
•GTO remote-mounted RF receiver tuned to 318 MHz.
• Opener length with push-pull tube fully retracted is 371/4", mounting point to mounting point. Max stroke 19".
• Adjustable auto-close timer (OFF to 120 s), and obstruction sensitivity.
• Power terminal bock accommodates a transformer or solar panels.
• DIP switches simplify setup of gate opener.
• Accessory terminal block fully compatible with all Mighty Mule access controls.
• 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
• The Gate Capacity Chart shows approximate cycles, per day, you can expect from the Mighty Mule 352 Au-
tomatic Gate Opener when powered with a transformer. Actual cycles may vary slightly depending upon the
type and condition of gate and installation.
MIGHTY MULE® 352 E-Z GATE OPENER
Technical Specifications
* These specifications are subject
to change without notice.
Gate Weight
Gate Length
Number of Cycles Per Day
Mighty Mule 352 Gate Capacity /Cycle Chart
Estimated number of daily cycles, based on use with a transformer and one(1) 12 Volt battery.
550 lbs.
450 lbs.
350 lbs.
250 lbs.
150 lbs.
100 lbs.
50 lbs.
62
67
72
77
82
87
92
5’ - 6’
57
62
67
72
77
82
87
8’
57
62
67
72
77
82
10’
57
62
67
72
77
12’
57
62
67
72
14’
57
62
67
16’
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
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 22 or call [phone] or [phone] for more information.
* An operation cycle is one full opening and closing of the gate.
NOTE: "NR" indicates
this size and weight
combination is not
recommended for the
Mighty Mule 352.

Mighty Mule 352 11
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 and to avoid backsplash from rainwater.
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.
32 foot power cable connects
SLAVE to 12 Volt marine or
automotive type battery. (run in
PVC conduit)
32 foot communication cable
allows the MASTER and SECOND
gate openers to operate as an
integrated dual gate system. (run
in PVC conduit)
You will need to trench across the
driveway in order to lay conduit
for the second battery harness
and communication cable.
120 Volt indoor
Transformer
(surge protector
not supplied)
Fence Post
Set in Concrete
Run 1000' (max.) of low
voltage wire to battery
from transformer
(wire not included).
PVC conduit (not included)
to protect wire from lawn
mowers and weed eaters.
Gate Swings Evenly and Freely
Hung Firmly and Plumb Receiver
Gate Bracket
Master Opener
10'
Battery Harness
Second Opener
Closed Position Positive Stop Plates
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 dual
gate. Mounting the openers on masonry columns requires special procedures; see Column Installation
Information on page 42 if you intend to mount the openers on columns. Furthermore, if you have push-
to-open gates, you will need to purchase 2 push-to-open brackets (FM148) (see Accessory Catalog) to
properly configure your system. See push-to-open installation on page 36 before proceeding.
Horizontal Cross Member
Vertical Cross Member

12 Mighty Mule 352
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)
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 (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.
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
Recommended Reinforcement Examples
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.

Mighty Mule 352 13
Determining the Mounting Position
of the Post Bracket Assembly and the Gate Bracket
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.
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, 3/8" lock
washer and 3/8" 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 bushings. 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
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 (FM148) (see Accessory
catalog). Also, see Push-to-
Open Installation beginning on
page 36.
Clevis Pin
Hairpin Clip
Post Bracket Assembly
Bushing
Rear Mount
Opener
Clevis Pin
Hairpin Clip
Bushing
Gate Bracket
Front Mount
Level Opener
Fence Post
Gate In Open Position
LEVEL horizontal cross member
Post Bracket Assembly
Gate Bracket

14 Mighty Mule 352
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.
Step 6
After verifying 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.
IMPORTANT: While determining the mounting point for the post pivot bracket assembly, be sure that the
position allows for minimum 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.
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.

Mighty Mule 352 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
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
Gate In Open Position
LEVEL horizontal cross member
Mark cross member through middle of
gate bracket slots and drill 3/8" holes

16 Mighty Mule 352
Mounting the Master Opener
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.
Level Opener
Gate In Open Position
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
LEVEL horizontal cross member
Mounting the Second Opener
Step 12
Install the second opener on the remaining gate leaf by repeating Step 3 through Step 11, starting on page
13. After you have mounted the second opener, proceed to Installing the Positive Stops.
1Z]aSR>]aWbW]\
Ab]^>ZObSa
5ObS6W\US
0/BB3@G0=F
5ObS6W\US
BVSUObSZSOTQO\]^S\
c^b]Ò[Of
=^bW]\OZ5`]c\RAb]^
PS\SObVUObS
BVSUObSZSOTQO\]^S\
c^b]Ò[Of
;/AB3@5/B3A31=<25/B3
Installation of the Closed Position Stops
The Mighty Mule® 352 Gate Openers firmly hold the gates in the closed position using
positive stops. The positive stops help stabilize the gate leaves in the closed position.
To further enhance stability and security, we strongly recommended using an optional
Mighty Mule® Automatic Gate Lock (see Accessory Catalog) with your dual gate.
IMPORTANT: You need to
determine which side of the
driveway you will place the battery.
The MASTER gate and gate opener
should be mounted on the same
side as the battery. The gate and
gate opener on the opposite side
of the driveway from the MASTER
and battery will be referred to as the
SECOND gate and gate opener.
Illustration A