Harbor Freight Tools 91146 User Manual

MIG WELDER - 250 AMP

®

Model 91146

ASSEMBLY AND OPERATING INSTRUCTIONS

3491 Mission Oaks Blvd., Camarillo, CA 93011

Visit our Web site at: http://www.harborfreight.com

Copyright© 2005 by Harbor F reight Tools®. All rights reserved. No portion of this
manual or any artwork contained herein may be reproduced in any shape or form

without the express written consent of Harbor Freight Tools.

For technical questions, please call 1-800-444-3353.

PRODUCT SPECIFICATIONS

Item Description

Electrical Requirements Input Voltage: 220V / 60 Hz / 45 Input Amperage

Power Cord: 10 AWG @ 6’ Long

Power Plug: 220V (not included), Requires 50 Amp Circuit
Duty Cycles 60% @ 250 Amps / 100% @ 195 Amps
Maximum Welding
Thickness Capacity
Welding Current 30 – 250 Amps
Required Wire Sizes .024” To .047” Diameter
Wire Control Settings Internal, Spot & Pause, 4 Time, & 2 Time
Gun Coolant Type Air Cooled
Fuse Type 3 AMP Bu ss Fuse
Gun Power Cab le Length 13’
Ground Clamp Cable Length 13’
Wheels Front: Swivel Castors / 3-1/4” Diameter x 1” Thick

Accessories Gas Pressure Regulator w/Flow Meter

Weight 187 Pounds

Up To 3/8” Mild Steel

Rear: Rigid / 8” Diameter x 1-1/2” Thick on 7/8” Diameter Axle

Welding Gloves / Face Mask / 1 Torch Liner / 5 Spare Tips

SAVE THIS MANUAL

You will need this manual for the safety warnings and precautions, assembly, operating,
inspection, maintenance and cleaning procedures, parts list and assembly diagram.
Keep your invoice with this manual. Write the invoice number on the inside of the front
cover. Keep this manual and invoice in a safe and dry place for future reference.

UNPACKING

When unpacking, check to make sure all the parts shown on the Parts Lists on pages 26
and 27 are included. If any parts are missing or broken, please call Harbor Freight Tools
at the number shown on the cover of this manual as soon as possible.

GENERAL SAFETY RULES

WARNING!

READ AND UNDERSTAND ALL INSTRUCTIONS

Failure to follow all instructions listed below may result in

electric shock, fire, and/or serious injury.

SA VE THESE INSTRUCTIONS

WORK AREA

1. Keep your work area clean and well lit. Cluttered benches and dark areas
invite accidents.

2. Do not operate welding equipment in explosive atmospheres, such as in
the presence of flammable liquids, gases, or dust. Welding equipment

creates sparks which may ignite the dust or fumes.

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 2

3. Keep bystanders, children, and visitors away while operating welding
equipment. Distractions can cause you to lose control. Protect others in the
work area from arc rays, sparks, and slag. Provide barriers or shields as
needed.

ELECTRICAL SAFETY

1. Grounded welding equipment must be plugged into an outlet properly
installed and grounded in accordance with all codes and ordinances.
Never remove the gr ounding prong or modify the plug in any way. Do not
use any adapter plugs. Check with a qualified electrician if you are in
doubt as to whether the outlet is properly grounded. If the welding equipment

should electrically malfunction or break down, grounding provides a low
resistance path to carry electricity away from the user .

2. Avoid body contact with gr ounded surfaces suc h as pipes, radiators,
ranges, and refrigerators. There is an increased risk of electric shock if y our
body is grounded.

3. Do not expose welding equipment to rain or wet conditions. Water entering
welding equipment will increase the risk of electric shock.

4. Do not abuse the Power Cord. Never use the Power Cor d to carry welding

equipment or pull the Plug from an outlet. Keep the Power Cor d a wa y fr om
heat, oil, sharp edges, or moving parts. Replace damaged P o wer Cords
immediately. Damaged P o wer Cords increase the risk of electric shock.

5. When operating welding equipment outside, use an outdoor extension cord
marked “W-A” or “W”. These extension cords are rated for outdoor use, and

reduce the risk of electric shock.

The minimum extension cord size for this tool is 6 GAUGE for cords UP TO 25’ LONG.

CORDS LONGER THAN 25’ SHOULD NOT BE USED WITH THE WELDER.

PERSONAL SAFETY

1. Stay alert. W atc h what y ou are doing, and use common sense when
operating welding equipment. Do not use welding equipment while tired or
under the influence of drugs, alcohol, or medication. A moment of inattention

while operating welding equipment may result in serious personal injury.

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 3

2. Dress properly . Do not wear loose c lothing or je welry. Contain long hair .
Keep your hair, clothing, and gloves away from hot or moving parts. Loose
clothes, jewelry, or long hair can be caught in hot or moving par ts.

(See page 8, number 3, for recommended safety clothing.)

3. Avoid accidental starting. Be sure the Power Switch is off before plugging
in. Plugging in welding equipment with the Power Switch on invites accidents.

4. Remove adjusting keys or wrenches before turning on the welding
equipment. A wrench or a k e y that is left attached to an electrically charged part

of the welding equipment may result in personal injury.

5. Do not overreach. Keep proper footing and balance at all times. Proper
footing and balance enables better control of the welding equipment in
unexpected situations.

TOOL USE AND CARE

1. Use clamps (not included) or other practical ways to secure and support
the workpiece to a stable platform. Holding the work by hand or against your

body is unstable and may lead to loss of control.

2. Do not force the welding equipment. Use the correct equipment for your
application. The correct equipment will do the job better and safer at the rate for
which it is designed.

3. Do not use the power tool if the Power Switch does not turn it on or off.
Any equipment that cannot be controlled with the Power Switch is dangerous and
must be replaced.

4. Disconnect the Power Cord Plug fr om the power source before making any

adjustments, changing accessories, or storing the welding equipment.

Such prev entive safety measures reduce the risk of starting the welding
equipment accidentally.

5. Store idle welding equipment out of reach of children and other untrained
persons. Welding equipment is dangerous in the hands of untrained users.

6. Maintain welding equipment with care. K eep equipment clean and dry.
Properly maintained equipment is less likely to malfunction and is easier to
control. Do not use damaged w elding equipment. Tag damaged equipment “Do
not use” until repaired.

7. Check for misalignment or binding of moving parts, breakage of parts, and

any other condition that may affect the equipment’s operation. If damaged,
have the equipment serviced before using. Many accidents are caused by

poorly maintained equipment.

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 4

8. Use only accessories that are recommended by the manufacturer for your
model. Accessories that may be suitable for one type of welding equipment may
become hazardous when used on another type of equipment

SERVICE

1. Equipment service must be performed only by qualified repair personnel.
Service or maintenance performed by unqualified personnel could result in a risk
of injury.

2. When servicing welding equipment, use only identical replacement parts.

Follow instructions in the
of this manual. Use of unauthorized parts or failure to follo w maintenance

instructions may create a risk of electric shock, burns, or other injury .

“Inspection, Maintenance, And Cleaning”

section

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 5

GROUNDING

WARNING!

Improperly connecting the grounding wire can result in the risk of electric shock.
Check with a qualified electrician if you are in doubt as to whether the outlet is
properly grounded. Do not modify the power cord plug provided with the tool.
Never remove the grounding prong from the plug. Do not use the tool if the power
cord or plug is damaged. If damaged, have it repaired by a service facility before
use. If the plug will not fit the outlet, have a proper outlet installed by a qualified
electrician.

GROUNDED EQUIPMENT: EQUIPMENT WITH THREE PRONG PLUGS

1. W ARNING! The P ow er Cord requires the attachment of a 220 v olt,
grounded, 3-Prong Plug (not included). For safety purposes, only a qualified,

certified, electrician should attach a Plug to the Power Cord. Never modify the
Plug in any way. To comply with the National Electric Code, and to provide
additional protection from the risk of electrical shock, this product should only be
connected to a 220 volt electrical outlet that is protected by a Ground Fault Circuit
Interrupter (GFCI).

2. The grounding prong in the plug is connected to the green wire inside the cord to
the grounding system in the welding equipment. The green wire in the cord must
be the only wire connected to the equipment’s grounding system and must never
be attached to an electrically “live” terminal. (See Figure A.)

3. Your welding equipment must be plugged into an appropriate outlet, properly
installed and grounded in accordance with all codes and ordinances. The plug
and outlet should look like those in the following illustration. (See Figure A.)

POWER CORD

220 VOL T

POWER PLUG

(NOT INCLUDED)

ONL Y A QU ALIFIED, CERTIFIED

ELECTRICIAN SHOULD CONNECT A

POWER PLUG TO THE POWER CORD.

WARNING!

220 VOL T

ELECTRICAL OUTLET

(NOT INCLUDED)

FIGURE A

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 6

EXTENSION CORDS

The minimum extension cord size f or this tool is 6 GAUGE for cords UP TO 25’ LONG.

CORDS LONGER THAN 25’ SHOULD NOT BE USED WITH THIS WELDER.

1.

2. As the distance from the supply outlet increases, you must use a heavier gauge

3. The smaller the gauge number of the wire, the greater the capacity of the cord.

4. When using more than one extension cord to make up the total length, make sure

5. If you are using one extension cord for more than one tool, add the nameplate

6. If you are using an extension cord outdoors, make sure it is marked with the suffix

7. Make sure your extension cord is properly wired and in good electrical condition.

Grounded

extension cord. Using extension cords with inadequately sized wire causes a
serious drop in voltage, resulting in loss of power and possible tool damage.

The minimum extension cor d gauge for this tool is 6 AWG for cor ds up to 25’
long. Cor ds longer than 25’ should not be used with this welder.

For example, a 14 gauge cord can carry a higher current than a 16 gauge cord.

each cord contains at least the minimum wire size required.

amperes and use the sum to determine the required minimum cord size.

“W-A” (“W” in Canada) to indicate it is acceptab le f or outdoor use.

Always replace a damaged extension cord or have it repaired by a qualified
electrician before using it.

welding equipment require a three wire extension cord.

8. Protect your extension cords from sharp objects, excessive heat, and damp or wet
areas.

SYMBOLOGY

Double Insulated

Canadian Standards
Association

Underwriters
Laboratories, Inc.

V ~

A

FIGURE C

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 7

no

xxxx/min.

Volts Alternating Current

Amperes

No Load Revolutions
per Minute (RPM)

SPECIFIC SAFETY RULES

1. Maintain a safe working environment. Keep the work area well lit. Make sure
there is adequate surrounding workspace. Always keep the work area free of
obstructions, grease, oil, trash, and other debris. Do not use the Welder in areas
near flammable chemicals, dusts, and vapors.

2. Maintain labels and nameplates on the W elder . These carry important
information. If unreadable or missing, contact Harbor Freight Tools for a
replacement.

3. Prevent eye injury and burns. Wearing and using personal safety clothing and
safety devices reduce the risk of injur y. Wear ANSI approved safety impact
eyeglasses with a welding helmet featuring at least a number 10 shade lens
rating. Leather leggings, rubber soled, fire resistant shoes or boots should be
worn when using this Welder. Do not wear pants with cuffs, shirts with open
pockets, or any clothing that can catch and hold molten metal or sparks. Keep
clothing free of grease, oil, solvents, or any other flammable substances. Wear
dry, insulating gloves and protective clothing. Wear an approved head covering
to protect head and neck. Use aprons, cape, sleeves and shoulder covers, and
bibs designed and approved for welding procedures. When welding overhead or
in confined spaces, wear flame resistant ear plugs or ear muffs to keep sparks
out of ears.

4. Avoid overexposure to fumes and gases. Always keep your head out of the
fumes. Do not breathe the fumes. Use enough ventilation or exhaust, or both, to
keep fumes and gases from your breathing z one and gener al area. Where
ventilation is questionable, have a qualified technician take an air sampling to
determine the need for corrective measures. Use mechanical ventilation to
improve air quality. If engineering controls are not feasible, use an approved
respirator . Work in a confined area only if it is well ventilated, or while wearing an
air-supplied respirator. Follow OSHA guidelines for
(PEL’s) for various fumes and gases. F ollow the American Conference of
Governmental Industrial Hygienists recommendations for
(TLV’s) for fumes and gases. Have a recognized specialist in Industrial Hygiene
or Environmental Services check the operation and air quality and make
recommendations for the specific welding situation.

5. Do not perform welding or cutting operations near chlorinated hydrocarbon
vapors produced by degreasing or painting. The heat generated by arc rays
can react to form phosgene, a highly toxic gas.

6. Irritation of the eyes, nose, and throat are symptoms of inadequate
ventilation. Take immediate steps to improve ventilation. Do not continue
operations if symptoms persist.

Permissible Exposure Limits

Threshold Limit Values

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 8

7. When welding or cutting in small areas, the operator should be externally

near

accompanied by another person (standing
observe accident prevention procedures.

8. When welding or cutting, be aware that high frequency radiation may be
produced which can interfere with radio navigation, safety devices,
computers, and communications equipment. Before operating, have a

qualified technician check out that possibility.

9. Keep high frequency source doors and panels tightly shut. Keep spark
gaps at the correct settings. Use proper grounding and shielding to minimize the
possibility of interference. Keep all cables close together and close to the
ground. Locate the welding or cutting operation as far as possible from sensitive
electronic equipment, or have the electronic equipment shut down temporarily.

10. Prevent accidental fires. Remove any combustible material from the work
area. When possible, move the work to a location well away from combustible
materials. If relocation is not possible, protect the combustibles with a cover
made of fire resistant material. Remove or make safe all combustible materials
for a radius of 35 feet (10 meters) around the work area. Use a fire resistant
material to cover or block all open doorways, windows, cracks, and other
openings. Enclose the work area with portable fire resistant screens. Protect
combustible walls, ceilings, floors, etc., from sparks and heat with fire resistant
covers . If working on a metal wall, floor, ceiling, etc., prev ent ignition of
combustibles on the other side by moving the combustibles to a safe location. If
relocation of the combustibles is not possible, designate someone to serve as a
fire watch, equipped with a fire extinguisher, during the welding process and at
least one half hour after the welding is completed. Do not place the torch on any
material other than bare concrete until the torch is completely cooled. Do not
weld on materials having a combustible coating or combustible internal structure
such as walls or ceilings, without an approved method for eliminating the hazard.
Do not dispose of hot slag in containers holding combustible materials. Keep a
fire extinguisher nearby, and know how to use it. After welding, make a thorough
examination for evidence of fire. Be aware that easily visible smoke or flame
may not be present f or some time after the fire has started. Do not w eld in
atmospheres containing dangerously reactive or flammable gasses, vapors,
liquids, and dust. Provide adequate ventilation in work areas to prevent
accumulation of flammable gases, vapors, or dust. Do not apply heat to a
container that has held an unknown substance or a combustible material whose
contents, when heated, can produce flammable or explosive vapors. Clean and
purge containers before applying heat. Vent closed containers, including
castings, before preheating or welding. Note: Use caution when welding
galvanized metal; toxic gases are formed and must be ventilated properly.

the enclosed work area) to

11. Read and understand all instructions and safety precautions as outlined in
the manufacturer’s manual for the material you will weld.

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 9

12. Industrial applications must follow OSHA requirements.

13. Never plug the Power Cord of this product into an electrical outlet while

standing on a wet or damp surface.

14. Connect the earth ground as near as possible to the operating area. Earth
connections to structural parts of the building or other places distant to the
operating area will reduce their effectiveness and increase the danger of electric
shock.

15. In addition to grounding the workpiece with the W elder Grounding Clamp, an
earth grounding of the workpiece is recommended. Ground it directly to an
earth pipe or grounding rod with a separate cable of appropriate size.
IMPORTANT: Only a qualified, certified electrician should perform this
procedure.

16. Do not touch the welding wire if you are in contact with the workpiece,

ground, or another welding wire from a different machine.

17. Do not allow the welding wire to touch earth ground. Accidental earth
discharges may cause overheating and fire hazards.

18. Do not pass equipment cables through or near lifting chains, crane cables,

or any electrical lines.

19. Never use the Welder near water. Ensure that the surrounding area and cutting
objects are dry. Do not spray water or other liquids on or near the Welder.

20. Avoid all direct contact between the skin and wet garments and metal parts
under electrical power. Check that gloves and protective clothing are dry.

21. Never leave the Welder unattended when it is plugged into an electrical
outlet. Make sure to unplug it from its electrical outlet before leaving the area.

22. Do not unplug the Welder by pulling on the Power Cord. Keep the Power

Cord away from heated surfaces.

23. Always turn off the Welder in the event of a power failure.

24. Significant DC electrical voltage exists after turning off and unplugging the
Welder. Discharge the electrode to ground before handling.

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 10

25. Performance of this Welder may vary depending on variations in local line
voltage. Extension cord usage may also affect tool performance.

26. Always turn off the Welder and unplug the unit from its electrical outlet

before performing any inspection, maintenance, or cleaning procedures.

27. Use the right tool or attachment for the right job. Do not attempt to force a
small tool or attachment to do the work of a larger industrial tool or attachment.
There are certain applications for which this product was designed. It will do the
job better and more safely at the rate for which it was intended. Do not modify
this product, and do not use this product for a purpose for which it was not
intended.

28. Proper cylinder care: Secure cylinders to the Base of the Welder , a w all, or
post to prevent them from falling. All cylinders should be used and stored in an
upright position in a well ventilated area. Nev er drop or strike a cylinder. Do not
use cylinders that have been dented. Cylinder caps should be used when
moving or storing cylinders. Empty cylinders should be kept in specified areas
and clearly marked “empty”. Nev er use oil or grease on an y inlet connector, outlet
connector, or cylinder valve. Additional specific instructions for the safe handling
of cylinders should be supplied by your cylinder supplier and covered under local,
state, and federal regulations governing pressurized gases.

29. WARNING! The brass components of this product contain lead, a chemical
known to the State of California to cause birth defects (or other reproductive
harm).

30. WARNING! This product, when used for welding, cutting, and similar
applications, produces chemicals known to the State of California to causecancer
and birth defects (or other reproductive harm).

(California Health & Safety code 25249.5, et seq.)

(California Health & Safety code

25249.5, et seq.)

31. WARNING! People with pacemakers should consult with their physician(s)
before using this product. Operation of electrical equipment in close proximity to
a heart pacemaker could cause interference or failure of the pacemaker.

32. WARNING! The warnings, precautions, and instructions discussed in this
instruction manual cannot cover all possible conditions and situations that may
occur. It must be understood by the operator that common sense and caution
are factors which cannot be built into this product, but must be supplied by the
operator.

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 11

PRODUCT OVERVIEW

1. This Welder is designed for MIG/MAG welding on mild steel, stainless steel, and
nonferrous materials up to 3/8” thickness. Additional features of this unit are as
follows: (See Figure D.)

A. Constant voltage transformer with step-up adjustment.
B. Digital step-less electronic speed control.
C. 2/4 Times, interval, and spot/pause welding.
D. Pre-gas and post-gas flow.
E. Soft start, burnback.
F . Real-time digital volt-amp meter.
G. T w o inductance outlets (High & Low).
H. Easy connect, twist-lock, male and female welding cables.
I. Forced air cooling system.
J. Thermal overload protection.

4A

12

8
9

10

5C

6

5B

4

7

FRONT

PANEL

14

1

5A

3B

3A

CONTROLS

2

Part # Description Part # Description

1 Front Panel 5C Wire Speed Potentiometer
2 MIG Gun Outlet 6 Wire Speed Mode Selector
3A High Inductance Outlet 7 Fuse
3B Low Inductance Outlet 8 Over-Heating LED
4 Voltage Selector 9 Operating LED
4A Voltage Selector Switch 10 Power Switch
5A Pause Timer 12 Digital Volt/AMP Display
5B Spot Timer 14 Digital Wire Feed Speed Display

FIGURE D

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 12

29 Gas Inlet Valve
30 Back Panel

FIGURE E

BACK

PANEL

CONTROLS

29

30

Part # Description

PRE-

GAS

TIMER

(5G)

INCHING
BUTTON

(36A)

SOFT

START

(5F)

BURN
BACK

TIMER

(5E)

POST-

GAS

TIMER

(5D)

GAS TEST

BUTTON

(36B)

CONTROLS

Part # Description Part # Description

5D Post-Gas Timer 5G Pre-Gas Timer
5E Burn Back Timer 36A Inching Button
5F Soft Start Potentiometer 36B Gas Test Button

FIGURE F

SIDE

PANEL

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 13

ASSEMBLY INSTRUCTIONS

NOTE: For additional references to the parts listed in the following pages, refer to the
Assembly Diagrams on pages 26 and 28.

To Attach A Power Cord Plug:

1. WARNING! Only a qualified, certified electrician should attach a 220
volt Power Plug (not included) to the Power Cord of the Welder.

2. For further instructions, refer to page 5 and page 6 of this manual.

To Attach The Rear Wheels And Front Castor Wheels:

1. WARNING! Prior to performing an y further assembly pr ocedures,
make sure the Po wer Cor d Plug of the Welder is unplugged from its
electrical outlet.

2. To attach the two Rear Wheels (47) to the W elder, slide a Wheel onto each end
of the Axle located at the rear of the Base (19). Secure both Wheels to the Axle b y
inserting one Cotter Pin through each end of the Axle. Once inserted, make sure
to spread each Cotter Pin to keep them in place. (See Figure G.)

3. To attach the two Front Castor Wheels (48) to the W elder, align the f our holes in
each top plate of a Castor Wheel with the f our

threaded

mounting holes located
in each corner at the bottom/front of the Welder . Use four Bolts (45) and four
Washers (46) to secure each Castor Wheel to the Base. (See Figure G.)

COTTER PIN (44)

AXLE

BASE (19)

CASTOR WHEEL (48)
WASHER (46)

FRONT

FIGURE G

REAR WHEEL (47)

BOLT (45)

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 14

To Attach The Gun Power Cable And Ground Clamp Cable:

1. Insert the plug of the Gun Power Cable (40A) firmly into the MIG Gun Outlet (2).

(See Figure H.)

2. Insert the plug of the Ground Clamp Cable (201) firmly into the High Inductance
Outlet (3A) or the Low Inductance Outlet (3B). NOTE: The High Inductance
Outlet allows for a higher welding heat, resulting in a deeper penetration of the
welding wire into thicker workpieces. The Low Inductance Outlet allows for a
lower welding heat, and is typically used for thinner workpieces. (See Figure H.)

GUN

POWER

CABLE (40A)

MIG

GUN

OUTLET

(2)

HIGH INDUCT ANCE OUTLET (3A)

LOW INDUCT ANCE OUTLET (3B)

GROUND

CLAMP

CABLE (201A)

FIGURE H

To Install Welding Wire Spool And Adjust Wire Tension:

1. Open the Upper Right Side Panel (21), and remove the Lock Knob on the Wire
Spool Hub (33). (See Figure I, next page.)

2. Insert a Wire Spool (not included) onto the Wire Spool Hub (33), and secure the
Wire Spool in place with the Lock Knob. (See Figure I.)

3. Lower the Pressure Adjustment Knob on the Wire Feeder (37). (See Figure I.)

4. Hold the welding wire tightly to keep it from unraveling. Then pull out about 6” of
welding wire from the Wire Spool, and make a clean cut at the end of the wire.

(See Figure I.)

5. Push the welding wire through the guides in the Wire Feeder (37) and about 4”
into the Gun Power Cable (40A). Continue to hold the wire. (See Figure I.)

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 15

4.

WIRE SPOOL

(NOT INCLUDED)

(40A)

(40A)

6”

CONTACT TIP

(90A)

GAS NOZZLE

(100A)

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 16

6. Turn the Pressure Adjustment Knob

clockwise

to tighten the tension of the
welding wire. NOTE: Use the Pressure Indicator Scale to set the desired drive
roll pressure. (See Figure I.)

7. Remove the Gas Nozzle (100A) and Contact Tip (90A). (See Figure I.)

8. Turn the Power Switch (10) to its “ON” position. (See Figure I.)

9. Depress the Inching Button (36A) until the welding wire extends about 1” out of
the Gun. Then, reinstall the Gas Nozzle (100A) and Contact Tip (90A).

(See Figures F and I.)

10. Feed the welding wire out of the Gun to check for proper drive roll pressure. If
necessary , tighten the Pressure Adjustment Knob to pre vent the wire from
slipping. (See Figure I.)

11. Cut off the welding wire so that only about 3/8” e xtends from the Gun. Then
close the Upper Right Side Panel (21) of the welding machine and turn the
Po wer Switch (10) to its “OFF” position. (See Figure I.)

To Install A Gas Cylinder:

1. CAUTION! Using an oversized gas cylinder can cause tipping, result
ing in cylinder and equipment damage and personal injury. Do not exceed
maximum cylinder weight of 100 pounds.

2. CAUTION! Do not use the Argon/Mixed Pressure Regulator/Flow Meter
(43) with CO shielding gas. To use CO shielding gas, you must install a
CO gas Pressure Regulator/Flow Meter (not included).

2

2

2

3. With assistance, set the cylinder upright on the Base (19) of the Welder. Make
sure to use the accessory Chain to secure the cylinder to the body of the Welder.

(See Figure J, next page.)

4. Remove the Cap from the cylinder. Stand to the side of the cylinder Valve, and
open the Valve slightly to blow dust and dirt from the Valve. Then, close the
Valve. (See Figure J.)

5. Make sure the Flow Adjust on the Pressure Regulator/Flow Meter (43) is turned
off. Then, screw the Pressure Regulator/Flow Meter firmly onto the cylinder
Valve. (See Figure J.)

6. Attach the Gas Hose (202A) from the Pressure Regulator/Flow Meter (43) to
the Gas Inlet Valve (29) located on the Back Panel (30) of the Welding machine.

(See Figure J.)

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 17

7. Adjust the flow rate of the gas b y turning the Flow Adjust. The typical flow rate is
20 CFH (cubic feet per hour). Check the welding wire manuf acturer’s
recommended flow rate. (See Figure J.)

PRESSURE REGULA TOR

FLOW METER

(43)

GAS HOSE

(202A)

CHAIN

GAS INLET VALVE

CYLINDER CAP

CYLINDER VALVE

ARGON GAS

OR

MIXED GAS

(29)

FIGURE J

BACK PANEL (30)

Welding Gun Duty Cycle And Overheating:

1. IMPORTANT! Welding longer than the rated duty cycle for this Welding
equipment can damage the Gun and void its warranty.

2. Duty cycle is a percentage of 10 minutes that the unit can weld at its rated load
without overheating. (See Figure L, page 20.)

3. If the unit should overheat, the thermostat opens, output stops, and the cooling
fans continue to run. Wait fifteen minutes for the unit to cool. Reduce amperage
or voltage, or duty cycle, before welding.

4. This Welder, at its 60% duty cycle, can run continuously under load for 6 minutes
out of each 10 minute period. (See Figure L.)

5. NOTE: Higher duty cycles can be used at lower currents. (See Rating Plate

information on Front Panel.)

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 18

The Four Welding Features:

NOTE: The following four welding features are designed to optimize specific

welding processes. (See Figure K.)

1. 2-TIME: Typically, the standar d welding process used. To operate, turn the
Wire Speed Mode Selector (6) to its 2-Time setting. Squeeze the Welding Gun
Trigger (18A) to start the Pre-Gas. Then, weld accordingly. Release the Welding
Gun Tr igger to stop welding. The Post-Gas will continue to deliver the protective
gas according to the setting of the Post-Gas Timer (5D).

(See Figures D, F, and K.)

2.

4-TIME: The benefit of this process is that there is no need to continuously
squeeze the Welding Gun T rigger (18A) during a long welding job. To

operate, turn the Wire Speed Mode Selector (6) to its 4-Time setting. Squeeze
and quickly release the Welding Gun Trigger to start and stop welding. The
Post-Gas will contin ue to deliv er the protectiv e gas according to the setting of the
Post-Gas Timer (5D). (See Figures D, F, and K.)

3. SPOT AND PAUSE: This process reduces the number of times the operator

must squeeze the W elding Gun Trigger (18A) while spot welding. This
process also allows the operator to lower the welding heat for thin material
to av oid burn-thr ough. To operate, turn the Wire Speed Mode Selector (6) to

its Spot and Pause setting. By squeezing the Welding Gun Trigger (18A), the
operator can weld and pause in cycle according to the settings of the P ause Timer
(5A) and Spot Timer (5B). (See Figures D, F, and K.)

4. INTERVAL: This process allows the operator to produce the same length
and quality of the welding bead more efficiently. To operate, turn the Wire
Speed Mode Selector (6) to its Interval setting. By squeezing the W elding Gun
Trigger (18A), the operator can weld in one cycle according to the preset welding
time. (See Figures D , F, and K.)

4-TIME SPOT AND PAUSE

WIRE SPEED MODE SELECTOR

(6)

2-TIME

FIGURE K

INTERVAL

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 19

.024” to .047” Hard or Flux Cored Wires

60% Duty Cycle at 250 Amperes Using Mixed Gases

6 Minutes Welding

Relation Between Duty Cycle And Weld Amperes.

100

80

60

DUTY CYCLE (%)

FIGURE L

40

20

0

0 100

4 Minutes Resting

200 300

WELD AMPERES

Relation Between Thickness, Diameter Of Wire, Wire Speed, Voltage, & Current*:

FIGURE M

*Do not change voltage while welding. Wire speed is a starting value only, and can be adjusted

while welding. Weld conditions also depend on other variables such as stickout, travel speed,

weld angle, cleanliness of metal, etc.

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 20

Relation Between Wire Feed Speed, Size Of Wire, & Welding Current:

FIGURE N

TROUBLESHOOTING GUIDE - WELDING MACHINE

Use larger welding leads.

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 21

TROUBLESHOOTING GUIDE - WELDING GUN & WIRE DRIVE

Problem Possible Cause

No arc. 1. Interruption of welding power circuit to welding

gun or workpiece.

2. Power source or control defective.

3. Trigger wire broken, cut, or disconnected.

4. Power source contractor not activated.
Arc between gas nozzle
and workpiece.
Welding gun body or
power cable overheated.

Welding wire melted
onto contact tip.

Irregular wire feed. 9. Drive roll pressure too low or too high.

1. Spatter build-up inside gas nozzle.

1. Welding current too high.

2. Contact tip not correctly tightened.

3. Ground clamp making poor contact.

4. Wire feed starts too late (burn-back).

5. Wire jammed in liner due to dirt accumulation

in liner or extreme bending of cable assembly.

6. Feed rate too low.

7. Contact tip too far away from workpiece.

8. Burn-back time set too long.

10. Faulty or worn liner.

11. Incorrect type or size of liner, or liner

incorrectly attached.

12. Faulty wire feed control.

13. Drive rolls worn or incorrectly installed. Incorrect

Size of drive rolls used.

INSPECTION, MAINTENANCE, AND CLEANING - WELDING MACHINE

1. WARNING! Make sure the Power Switch (10) is in its “OFF” position.
Unplug the Power Cord Plug from its electrical outlet, and allow the Welder to
completely cool before performing any inspection, maintenance, or cleaning
procedures. Note: Always ground the contact tip to insure that there is no
residual energy in the Welder.

2. Before each use, inspect the general condition of the W elder. Check f or
damaged electrical wiring, loose connections, cracked, b urnt, or broken parts,
and any other condition that may affect its safe operation. If abnormal noise or
vibration occurs, hav e the problem corrected before further use.

Do not use damaged equipment.

3. Every six months: Blow off or vacuum dirt and dust deposits on the Auxiliary
Transformer (23) and other components. Dirt or dust deposits on the W elding

Transformer and other internal components may reduce the insulating proper ty or
cause overheated Transformer. During heavy usage, clean monthly.

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 22

4. To replace the 3 AMP Buss Fuse: F ailure of the Welder to oper ate ma y be
caused by a blown 3 AMP Fuse (7) as indicated by its melted wire strand within
the Fuse. T o replace the Fuse , unscrew and remov e the Fuse Cap. Remo ve the
old Fuse, and install a new 3 AMP Fuse. Then, replace the Fuse Cap.

5. When storing, make sure to store the W elder in a saf e , clean, dry location out of
reach of children and unauthorized users.

6. CAUTION! All maintenance, service, and repairs not listed in this manual

are only to be attempted by a qualified service technician.

INSPECTION, MAINTENANCE, AND CLEANING - WELDING GUN

1. WARNING! Make sure the Power Switch (10) on the Welding Machine is
in its “OFF” position. Unplug the Power from its electrical outlet, and allow the
Welder to completely cool before performing any inspection, maintenance, or
cleaning procedures. Note: Always ground the contact tip to insure that there is
no residual energy in the Welder .

2. Before each use: Inspect the general condition of the Welding Gun. Check for
damaged electrical wiring/gas hose, loose connections, cracked, burnt, or broken
parts, and any other condition that may aff ect its saf e operation. If abnormal
noise or vibration occurs, hav e the prob lem corrected before further use.

Do not use damaged equipment.

3. Before each use: Clean welding spatter from the inside of the Gas Nozzle
(100A) and spray with an anti-spatter fluid.

4. To replace the Gun Contact Tip: Cut off the welding wire at the Contact Tip
(90A). Remove the Nozzle. Remove the old Contact Tip, and install a new
Contact Tip. Then, replace the Nozzle. (See Figure O.)

CONT A CT TIP (90A)

NOZZLE (100A)

FIGURE O

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 23

5. To replace the Gun Liner: Disconnect the Gun’ s Power Cable from the Welding
machine. Remove the Nozzle, Contact Tip, Adapter, Gas Diffuser, and Wire
Outlet Guide. Then, remove the old Liner. Lay the Gun’s Power Cable out
straight before installing a new Liner. Blow out the Gun Casing with compressed
air. Install and tighten the new Liner. Cut Liner off 3/4” from the Head Tube (3/8”
for aluminum). Then reinstall the Wire Outlet Guide , Gas Diffuser , Adapter,

Contact Tip, and Nozzle. (See Figure P.)

REMOVE NOZZLE (100A),

CONTACT TIP (90A),

ADAPTER, GAS DIFFUSER,

WIRE OUTLET GUIDE.

SWAN NECK (1A)

REMOVE OLD
LINER (130A).

BLOW OUT

GUN CASING.

LAY GUN POWER CABLE (40A)

OUT STRAIGHT BEFORE

INSTALLING NEW LINER.

FIGURE P

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 24

6. To clean exterior of Welding Gun: Use a damp cloth with a mild detergent.
Then, dry. Do not use solvents to clean the Gun.

7. When storing: Make sure to store the W elding Gun in a saf e, clean, and dry
location out of reach of children and unauthorized users.

8. WARNING! All maintenance, service, and repairs not listed in this manual

are only to be attempted by a qualified service technician.

PLEASE READ THE FOLLOWING CAREFULLY

THE MANUFACTURER AND/OR DISTRIBUTOR HAS PROVIDED THE PARTS LIST AND ASSEMBLY
DIAGRAM IN THIS MANUAL AS A REFERENCE TOOL ONLY. NEITHER THE MANUFACTURER OR
DISTRIBUTOR MAKES ANY REPRESENTA TION OR W ARRANTY OF ANY KIND TO THE BUYER THAT HE
OR SHE IS QUALIFIED TO MAKE ANY REPAIRS T O THE PR ODUCT , OR THA T HE OR SHE IS Q UALIFIED
TO REPLA CE ANY P AR TS OF THE PR ODUCT. IN F ACT, THE MANUF A CTURER AND/OR DISTRIBUTOR
EXPRESSL Y STA TES THA T ALL REPAIRS AND P ARTS REPLA CEMENTS SHOULD BE UNDERTAKEN BY
CERTIFIED AND LICENSED TECHNICIANS, AND NOT BY THE BUYER. THE BUYER ASSUMES ALL
RISK AND LIABILITY ARISING OUT OF HIS OR HER REPAIRS TO THE ORIGINAL PRODUCT OR
REPLACEMENT PARTS THERET O, OR ARISING OUT OF HIS OR HER INSTALLA TION OF REPLACEMENT

P ARTS THERETO .

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 25

PARTS LIST - WELDING MACHINE

Part # Description Part # Description Part # Description

1 Front Panel 12 D igital Volt/AMP Display 31 Cylinder Support
2 MIG G un Outlet 13 F ront Panel Bracket 32 Fan
3A High Inductance Outlet 14 Digital Wire Feed Speed

Display
3B Low Inductance Outlet 15 W elding Transformer 34 W ire Spool Support
4 Voltage Selector Knob 16 M agnetic Contractor 35 B ypass PCB
4A Voltage Selector Switch 17 8-Pin Relay 36A Inching Button
5A Pause Timer 18 8-Pin Relay Socket 36B G as Test Button
5B Spot Timer 19 Base 37 Wire Feeder
5C Wire Speed Potentiometer 20 Lower Right Side Panel 38 Rectifier
5D Post-Gas Timer 21 Upper Right Side Panel 39 Partition
5E Burn Back Timer 22 Input Terminal 40 Capacitor
5F S o ft S t a rt Po te n tio m e t e r 23 A u x ilia r y T ra n s fo r me r 41 W ir e S peed PC B
5G Pre-Gas Timer 24 Choke 42 Left Side Panel
6 Wire Speed Mode Selector 25 Resistor 43 Pressure Regulator/

7 Fuse 26 Partition 44 Cotter Pins
8 Overheating LED 28 S olenoid Valve 45 Bolts
9 Operating LED 29 G as Inlet Valve 46 Washers
10 Power Switch 30 B ack Panel 47 Rear W heels
11 Handle 48 Front Castor Wheels

33 Wire Spool Hub

Flo w Me ter

ASSEMBLY DIAGRAM - WELDING MACHINE

7

43

42

40

39

31

38

35

32

30

29

28

41

5G

5F

5E

5D

34

33

36A

11

10

9

8

5C

5B

6

4

5A

3B

3A

13

36B

26

37

14

15

1

16

2

17

18

25

24

22

23

47

21

20

44

NOTE:

Some parts are listed and shown

48

19

for illustration purposes only,

46

45

and are not available individually

as replacement parts.

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 26

PARTS LIST - WELDING GUN

Part # Description Part # Description

1A Swan Neck (MB 25 AK, 50° Bent) 58A Adapter Nut
4A Nozzle Spring 59A Central Adapter Block (KZ-2)
6A Gun Body, Brass 60A Nut (M10 x 1)
7A Gun Body, Plastic 61A O-Ring (4 x 1)
10A Ergonomic Handle 62A Trigger Wire Connector (female)
18A Trigger 80A Contact Tip Holder (M6, 35.0 mm)
40A Power Cable (4.00 m) 90A Contact Tip (Qty. 5)

40.1A Hex Nut (M10 x 1) 100A Gas Nozzle
44A Trigger Wire Connector 120A Insulated Liner
45A Insulating Sleeve 130A Teflon© Core Liner
46A Trigger Wire Connector (Male) 131A Core Liner Collet
54A Cable Support Spring (NW 19) 132A O-Ring (3.5 x 1.5)
56A Cable Support Machine Side 133A Core Liner Guide Tube
57A Screw (M4 x 6) 200A Spanner

57.1A Cover Cap (1) 201A Ground Clamp Cable

------------- -----------------------------------------------------202A Gas Hose

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 27

ASSEMBLY DIAGRAM - WELDING GUN

90A 80A

4A

100A

120A

1A

200A

201A: GR OUND CLAMP CABLE NOT SHOWN.
202A: GAS HOSE NO T SHOWN.

7A

18A

10A

44A

45A

44A

45A

130A 131A

54A

57A

133A

40.1A

46A

46A

132A

56A

57.1A

NOTE:

Some parts are listed and shown

for illustration purposes only,

and are not available individually

as replacement parts.

58A

62A

62A

40.1A

54A

59A 60A

61A

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 28

ELECTRICAL SCHEMATIC - WELDING MACHINE

SKU 91146 For technical questions, please call 1-800-444-3353. PAGE 29