Chicago Electric 97503 Installation manual

DUAL MIG WELDER
Model 97503
SET UP AND OPERATING INSTRUCTIONS
Diagrams within this manual may not be drawn proportionally.
Due to continuing improvements, actual product may differ slightly from the product described herein.
Distributed exclusively by Harbor Freight Tools®.
3491 Mission Oaks Blvd., Camarillo, CA 93011
Visit our website at: http://www.harborfreight.com
Read this material before using this product.
Failure to do so can result in serious injury.
SAVE THIS MANUAL.
Copyright©2008 by Harbor Freight 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 or replacement parts, please call 1-800-444-3353.

Page 2SKU 97503 For technical questions, please call 1-800-444-3353.
CONTENTS
IMPORTANT SAFETY
INFORMATION ............................ 3
GENERAL SAFETY RULES ..............3
SPECIFIC SAFETY RULES ...............5
SPECIFICATIONS.......................... 9
UNPACKING .................................. 9
LIST OF CONTENTS..........................9
INITIAL SET UP INSTRUCTIONS . 9
ASSEMBLY.........................................9
LOADING AND ADJUSTING
THE WIRE TENSION. ..............10
INSTALLING A GAS CYLINDER 11
OPERATING INSTRUCTIONS .... 12
TOOL SET UP ..................................12
WORK PIECE AND WORK AREA
SET UP ..........................................12
GENERAL OPERATING
INSTRUCTIONS ............................13
MAINTENANCE AND
SERVICING ............................... 16
CLEANING, MAINTENANCE, AND
LUBRICATION...............................16
NOZZLE CARE.................................16
CONTACT TIP CARE .......................16
REPLACING THE WELDING
TORCH LINER...............................17
TROUBLESHOOTING................. 18
WIRE FEED MOTOR RUNS
BUT WIRE DOES NOT FEED
PROPERLY. .............................. 18
WIRE CREATES A BIRD’S
NEST DURING OPERATION. ..18
WELDING ARC NOT STABLE. ..18
WELDER DOES NOT
FUNCTION WHEN
SWITCHED ON ........................18
WEAK ARC STRENGTH ............18
WIRE FEEDS, BUT ARC DOES
NOT IGNITE .............................19
WIRE FEEDS, BUT SHIELDING
GAS DOES NOT FLOW...........19
PLEASE READ THE FOLLOWING
CAREFULLY .................................. 19
PARTS LIST AND ASSEMBLY
DIAGRAM .................................. 20
LIMITED 1 YEAR / 90 DAY
WARRANTY .............................. 21

Page 3SKU 97503 For technical questions, please call 1-800-444-3353.
SAVE THIS MANUAL
Keep this manual for the safety
warnings and precautions, assembly,
operating, inspection, maintenance and
cleaning procedures. Write the product’s
serial number in the back of the manual
near the assembly diagram (or month
and year of purchase if product has no
number). Keep this manual and the
receipt in a safe and dry place for future
reference.
IMPORTANT SAFETY
INFORMATION
In this manual, on the labeling,
and all other information
provided with this product:
This is the safety alert
symbol. It is used to alert
you to potential personal
injury hazards. Obey all
safety messages that
follow this symbol to avoid
possible injury or death.
DANGER indicates
a hazardous
situation which, if not
avoided, will result in death or
serious injury.
WARNING
indicates a
hazardous situation which, if
not avoided, could result in
death or serious injury.
CAUTION, used
with the safety
alert symbol, indicates a
hazardous situation which, if
not avoided, could result in
minor or moderate injury.
NOTICE is used to
address practices
not related to personal injury.
CAUTION, without
the safety alert
symbol, is used to address
practices not related to
personal injury.
General Safety Rules
WARNING! Read all instructions
Failure to follow all instructions
listed below may result in
electric shock, re, and/or
serious injury. The term “power
tool” in all of the warnings listed
below refers to your line-operated
(corded) Dual MIG Welder.
SAVE THESE INSTRUCTIONS
Work area safety1.
Keep work area clean and wella.
lit. Cluttered or dark areas invite
accidents.
Do not operate power tools inb.
explosive atmospheres, such as in
the presence of ammable liquids,
gases or dust. Power tools create
sparks which may ignite the dust or
fumes.
Keep children and bystandersc.
away while operating a power
tool. Distractions can cause you
to lose control.
DANGER
WARNING
CAUTION
NOTICE
CAUTION

Page 4SKU 97503 For technical questions, please call 1-800-444-3353.
Electrical safety2.
Avoid body contact with groundeda.
surfaces such as pipes, radiators,
ranges and refrigerators. There is
an increased risk of electric shock if
your body is grounded.
Do not expose power tools to rainb.
or wet conditions. Water entering a
power tool will increase the risk of
electric shock.
Do not abuse the cord. Never usec.
the cord for pulling or unplugging the
power tool. Keep cord away from
heat, oil, sharp edges or moving
parts. Damaged or entangled cords
increase the risk of electric shock.
When operating a power toold.
outdoors, use an extension cord
suitable for outdoor use. Use of
a cord suitable for outdoor use
reduces the risk of electric shock.
Personal safety3.
Stay alert, watch what you area.
doing and use common sense
when operating a power tool. Do
not use a power tool while you are
tired or under the inuence of drugs,
alcohol or medication. A moment
of inattention while operating power
tools may result in serious personal
injury.
Use safety equipment. Alwaysb.
wear eye protection. Safety
equipment such as arc shaded,
impact safety full face shield,
dust mask or respirator, heavy-
duty work gloves, non-skid safety
shoes, or hearing protection used
for appropriate conditions will
reduce personal injuries.
Avoid accidental starting. Ensurec.
the switch is in the off-position
before plugging in. Carrying power
tools with your nger on the switch
or plugging in power tools that have
the switch on invites accidents.
Remove any adjusting key or wrenchd.
before turning the power tool on. A
wrench or a key left attached to a
rotating part of the power tool may
result in personal injury.
Do not overreach. Keep propere.
footing and balance at all times.
This enables better control of the
power tool in unexpected situations.
Power tool use and care4.
Do not force the power tool. Usea.
the correct power tool for your
application. The correct power tool
will do the job better and safer at the
rate for which it was designed.
Do not use the power tool if theb.
switch does not turn it on and
off. Any power tool that cannot
be controlled with the switch is
dangerous and must be repaired.
Disconnect the plug from thec.
power source before making
any adjustments, changing
accessories, or storing power
tools. Such preventive safety
measures reduce the risk
of starting the power tool
accidentally.
Store idle power tools out ofd.
the reach of children and do not
allow persons unfamiliar with the
power tool or these instructions
to operate the power tool. Power
tools are dangerous in the hands
of untrained users.
Maintain power tools. Check fore.
misalignment or binding of moving
parts, breakage of parts and any

Page 5SKU 97503 For technical questions, please call 1-800-444-3353.
other condition that may affect the
power tool’s operation. If damaged,
have the power tool repaired before
use. Many accidents are caused by
poorly maintained power tools.
Use the power tool, accessories andf.
tool bits etc., in accordance with
these instructions and in the manner
intended for the particular type of
power tool, taking into account the
working conditions and the work to
be performed. Use of the power tool
for operations different from those
intended could result in a hazardous
situation.
Service5.
Have your power tool serviced bya.
a qualied repair person using only
identical replacement parts. This will
ensure that the safety of the power
tool is maintained.
Specic Safety Rules
Maintain labels and nameplates on1.
the tool. These carry important safety
information. If unreadable or missing,
contact Harbor Freight Tools for a
replacement.
Avoid electrical shock. Do not permit2.
electrically live parts, cables, or
electrodes to contact skin, clothing,
or gloves. Wear ANSI-approved
protective clothing. This unit draws
enough current to cause serious
injury or death. Before turning the
welder on, check the electrode
holder to be sure that there are no
protruding screw heads, and that
all insulation is secure. Do not weld
unless you are insulated from ground
and the work piece.
Avoid eye and body damage. Arc3.
rays and infrared radiation can
injure eyes and burn skin. Wear
ANSI approved eye and body
protection. Do not allow viewing by
visitors without proper eye and body
protection. Use a Face Shield with
arc shaded lter plate.
Move ammable and explosive 4.
material at least 35 feet from the
welding arc to prevent welding sparks
or molten metal from starting a re.
Keep a type ABC re extinguisher
within easy reach. Thoroughly clean
the object being welded of any paint,
grease, or other foreign material.
Avoid unintentional starting. Prepare5.
to begin work before turning on the
tool.
Do not leave the tool unattended6.
when it is plugged into an electrical
outlet. Turn off the tool, and unplug
it from its electrical outlet before
leaving.
Use clamps (not included) or other7.
practical ways to secure and support
the work piece to a stable platform.
Holding the work by hand or against
your body is unstable and may lead
to loss of control.
This product is not a toy. Keep it out8.
of reach of children.
Industrial applications must follow9.
OSHA guidelines.
People with pacemakers should10.
consult their physician(s) before
use. Electromagnetic elds in close
proximity to heart pacemaker could
cause pacemaker interference or
pacemaker failure. In addition,
people with pacemakers should:

Page 6SKU 97503 For technical questions, please call 1-800-444-3353.
• Avoid operating alone.
• Do not use with power switch locked
on.
• Properly maintain and inspect to
avoid electrical shock.
• Any power cord must be properly
grounded. Ground Fault Circuit
Interrupter (GFCI) should also be
implemented – it prevents sustained
electrical shock.
WARNING: This product, when used11.
for welding, plasma cutting, soldering,
or similar applications, produces
chemicals known to the State of
California to cause cancer and birth
defects (or other reproductive harm).
(California Health & Safety Code §
25249.5, et seq.)
12. Cylinders can explode
when damaged:
Never weld on a pressurized or a•
closed cylinder.
Never lay a welding torch on a•
cylinder.
Never allow a welding electrode to•
touch the cylinder.
Keep cylinders away from any•
electrical circuits, including welding
circuits.
Keep protective cap in place over•
the valve except when the cylinder
is in use.
Use only correct gas shielding•
equipment designed specically
for the type of welding you will do.
Maintain this equipment properly.
Protect gas cylinders from heat,•
being struck, physical damage,
slag, ames, sparks, and arcs.
Always use proper procedures to•
move cylinders.
13. Prevent eye injury and
burns. Wearing and using
ANSI-approved personal
safety clothing and safety
devices reduce the risk for
injury.
Wear ANSI-approved safety eye•
goggles underneath welding eye
protection featuring at least a
Number 10 shade lens rating.
Leather leggings, re resistant •
shoes or boots should be worn
when using this product. 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 ammable
substances. Wear dry, insulating
gloves and protective clothing.
Wear an approved head covering•
to protect the head and neck. Use
aprons, cape, sleeves, shoulder
covers, and bibs designed and
approved for welding and cutting
procedures.
When welding/cutting overhead•
or in conned spaces, wear ame
resistant ear plugs or ear muffs to
keep sparks out of ears.
14. Prevent accidental res.
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

Page 7SKU 97503 For technical questions, please call 1-800-444-3353.
with a cover made of re resistant
material.
Remove or make safe all•
combustible materials for a radius
of 35 feet (10 meters) around the
work area. Use a re resistant
material to cover or block all open
doorways, windows, cracks, and
other openings.
Enclose the work area with portable•
re resistant screens. Protect
combustible walls, ceilings, oors,
etc., from sparks and heat with re
resistant covers.
If working on a metal wall,•
ceiling, etc., prevent ignition of
combustibles on the other side
by moving the combustibles to
a safe location. If relocation of
combustibles is not possible,
designate someone to serve as
a re watch, equipped with a re
extinguisher, during the cutting
process and for at least one half
hour after the cutting is completed.
Do not weld or cut materials•
having a combustible coating or
combustible internal structure,
as in walls or ceilings, without an
approved method for eliminating the
hazard.
Do not dispose of hot slag in•
containers holding combustible
materials. Keep a re extinguisher
nearby and know how to use it.
After spot welding, make a•
thorough examination for evidence
of re. Be aware that easily-
visible smoke or ame may not
be present for some time after
the re has started. Do not weld
or cut in atmospheres containing
dangerously reactive or ammable
gases, vapors, liquids, and dust.
Provide adequate ventilation in
work areas to prevent accumulation
of ammable gases, vapors, and
dust. Do not apply heat to a
container that has held an unknown
substance or a combustible
material whose contents, when
heated, can produce ammable or
explosive vapors. Clean and purge
containers before applying heat.
Vent closed containers, including
castings, before preheating,
welding, or cutting.
Do not touch live electrical parts.15.
Wear dry, insulating gloves. Do not
touch electrode or conductor tong
with bare hand. Do not wear wet or
damaged gloves.
Protect yourself from electric shock.16.
Do not use outdoors. Insulate
yourself from the work piece and
ground. Use nonammable, dry
insulating material if possible, or
use dry rubber mats, dry wood or
plywood, or other dry insulating
material big enough to cover your
full area of contact with the work or
ground.
Ensure that the unit is placed on a17.
stable location before use. If this unit
falls while plugged in, severe injury,
electric shock, or re may result.
Ground this product. This Welder18.
requires the attachment and use of a
UL-listed, 240 volt grounded, 3-prong,
electrical Power Cord Plug (not
included). Only a quali ed electrician
should install the Power Cord Plug.
Never remove the grounding prong
or modify the Power Cord Plug in any

Page 8SKU 97503 For technical questions, please call 1-800-444-3353.
way. Do not use adapter plugs with
this product.
Avoid overexposure to fumes and19.
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 zone and
general area.
Where ventilation is questionable, •
have a qualied 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.
Follow OSHA guidelines for•
Permissible Exposure Limits (PEL’s)
for various fumes and gases.
Follow the American Conference of•
Governmental Industrial Hygienists
recommendations for Threshold
Limit Values (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 specic
welding or cutting situation.
WARNING
INHALATION HAZARD:
Welding and Plasma Cutting Produce
TOXIC FUMES.
Exposure to welding or cutting
exhaust fumes can increase the risk
of developing certain cancers, such as
cancer of the larynx and lung cancer.
Also, some diseases that may be linked
to exposure to welding or plasma cutting
exhaust fumes are:
• Early onset of Parkinson’s Disease
• Heart disease • Ulcers
• Damage to the reproductive organs
• Inammation of the small intestine or
stomach • Kidney damage
• Respiratory diseases such as
emphysema, bronchitis, or pneumonia
Use natural or forced air ventilation and
wear a respirator approved by NIOSH to
protect against the fumes produced to
reduce the risk of developing the above
illnesses.
The warnings, precautions,20.
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.
SAVE THESE
INSTRUCTIONS.

Page 9SKU 97503 For technical questions, please call 1-800-444-3353.
SPECIFICATIONS
Welding Current 30 ~ 120 amps
Duty Cycle
20% at 105 amps;
40% at 75 amps;
90% at 50 amps;
100% at 30 amps
Input Power 230 VAC, 21 amps
(Peak) at 60 Hz
Open Circuit Voltage
(max) 36 VDC
Thermal Overload
Protection with Light
Automatic shutdown
and restart after cool
down
Wire Size
0.023 to 0.030 inch
steel and stainless
steel; 0.030 to 0.035
inch ux core and
aluminum
Welding Capacity 22 gauge to 3/16”
Steel
Wire Spool Size 2 lb. Spool
Weight 62.2 lbs.
UNPACKING
When unpacking, check to make sure
that the item is intact and undamaged. 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.
List of contents
Description Qty
Dual MIG Welder 1
Wheel 2
Axle 1
0.030” (0.8mm) Welding Tip 1
0.040 (1.0mm) Welding Tip 1
2 Pounds (0.030”) Flux Core Wire 1
Hand Held Shaded Face Shield 1
Brush Hammer 1
Welder Tip Close End Wrench 1
24” Strap For Gas Bottle 2
INITIAL SET UP
INSTRUCTIONS
Read the ENTIRE IMPORTANT
SAFETY INFORMATION section
at the beginning of this manual
including all text under
subheadings therein before set
up or use of this product.
TO PREVENT
SERIOUS INJURY
FROM ACCIDENTAL
OPERATION:
Turn the Power Switch of the
tool to its “OFF” position and
unplug the tool from its
electrical outlet before
assembling or making any
adjustments to the tool.
Note: For additional information regarding
the parts listed in the following pages,
refer to the Assembly Diagram near
the end of this manual.
Assembly
Slide the Axle (29) through the holes1.
at the rear of the unit.
Secure both Wheels (28) to the Axle2.
with the Locking Rings (42).
Lift up the Side Panel B (1) to3.
expose the wire spool and Wire
Feed Mechanism (10). Pull back on
the Feed Tensioner (CC) to free the
Feed Tension Arm (DD) and lift it up.
Remove Wire Feed Wheel Cover
(AA) screws, pull out the cover, and
pull out the Wire Feed Wheel (BB).
See photo page 10.
Note the two parallel grooves (one4.
is wider) on the circumference of the
Wire Feed Wheel (BB). On the sides
WARNING

Page 10SKU 97503 For technical questions, please call 1-800-444-3353.
of the wheel, reference markings
0.6 or 0.8 are stamped. They
corresponding with wire sizes: 0.6 =
0.023”, and 0.8 = 0.030” and 0.035”.
The groove facing to the inside of the
Wire Feed Mechanism (10) should
correspond with the size of wire used.
Align the axle key with the slot in the
Wire Feed Wheel and slide on the
Wire Feed Spool (BB). Replace Wire
Feed Wheel Cover (AA), the two
screws and tighten. See photo on
this page.
Lay the Welding Torch Cable (16) in5.
a straight line, perpendicular to the
welder unit, as much as possible.
This will prevent the wire from
puncturing the Welding Torch Cable
(16) when exiting the Wire Feed
Housing Throat (FF). See photo on
this page.
Remove the wing nut and the spool6.
axle nut from the Wire Spool Axle
(10). Make sure that the coil spring
is inserted onto the Spool Axle, and
place a spool with wire over the axle,
noting that the wire winding must
be in a counterclockwise direction.
Replace the Spool Axle Nut (10),
the wing nut, and tighten. Verify free
rotation of the spool over the axle.
Loading and adjusting the wire tension.
CAUTION:7. Hold onto the end of the
Welding Wire and keep tension on it
during the following steps. If this is
not done the Welding Wire will spring
backward and tangle. The end of the
wire should be straight and have no
burrs.
Twist off and pull to remove the8.
Nozzle and unscrew the Contact tip
of the Welder.
9.
Guide the tip through the feed tube
until it protrudes the Wire Feed
Wheel opening. Direct and feed at
least an inch of wire into the Wire
Feed Housing Throat (FF).
Close Wire Feed Mechanism (10)10.
over the wire, and adjust Feed
Tension Knob (D) until there is a
slight resistance on the wire.
Remove the nozzle and contact tip of11.
the Welder.
The following
steps require
applying power to the Welder.
Do not touch anything with
the Torch Handle or Welding
Wire or an arc will be ignited.
Do not touch the internal
components of the unit while
it is powered.
Plug the Power Cord into a grounded12.
230 volt electrical outlet and turn the
Welder ON.
Point the Torch Handle away from all13.
objects. Squeeze the Trigger Switch
DANGER
(EE)
(FF)
(AA) (BB)
(CC)
(DD)