Miller Electric MIGmatic M-25 User manual

MIGmatic M-25
Processes
Description
MIG (GMAW) Welding
OM-227 796A 2006−05
Semi-Automatic,Air-Cooled
MIG (GMAW) Welding Gun
Flux Cored (FCAW) Welding
™
Visit our website at
www.MillerWelds.com
File: MIG (GMAW)

Miller Electric manufactures a full line
of welders and welding related equipment.
For information on other quality Miller
products, contact your local Miller distributor to receive the latest full
line catalog or individual specification sheets. To locate your nearest
distributor or service agency call 1-800-4-A-Miller, or visit us at
www.MillerWelds.com on the web.
Thank you and congratulations on choosing Miller. Now you can get
the job done and get it done right. We know you don’t have time to do
it any other way.
That’s why when Niels Miller first started building arc welders in 1929,
he made sure his products offered long-lasting value and superior
quality. Like you, his customers couldn’t afford anything less. Miller
products had to be more than the best they could be. They had to be the
best you could buy.
Today, the people that build and sell Miller products continue the
tradition. They’re just as committed to providing equipment and service
that meets the high standards of quality and value established in 1929.
This Owner’s Manual is designed to help you get the most out of your
Miller products. Please take time to read the Safety precautions. They
will help you protect yourself against potential hazards on the worksite.
We’ve made installation and operation quick
and easy. With Miller you can count on years
of reliable service with proper maintenance.
And if for some reason the unit needs repair,
there’s a Troubleshooting section that will
help you figure out what the problem is. The
parts list will then help you to decide the
exact part you may need to fix the problem.
Warranty and service information for your
particular model are also provided.
Miller is the first welding
equipment manufacturer in
the U.S.A. to be registered to
the ISO 9001:2000 Quality
System Standard.
Working as hard as you do
−every power source from
Miller is backed by the most
hassle-free warranty in the
business.
From Miller to You
Mil_Thank 2005−04

TABLE OF CONTENTS
SECTION 1 −SAFETY PRECAUTIONS FOR GMAW WELDING GUNS −READ BEFORE USING 1. . . . . . . .
1-1. Symbol Usage 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-2. GMAW Gun Hazards 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-3. California Proposition 65 Warnings 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EMF INFORMATION 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 2 −SAFETY INFORMATION 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 3 −INSTALLATION 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-1. Specifications 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2. Duty Cycle And Overheating 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-3. Installing Gun 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 4 −OPERATION 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-1. Operating The Gun 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 5 −MAINTENANCE & TROUBLESHOOTING 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-1. Removing Nozzle, Contact Tip, And Adapter, Changing Liner, And Cleaning Gun Casing 6. . . . . . . . .
5-2. Replacing Switch And/Or Head Tube 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-3. Routine Maintenance 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-4. Troubleshooting 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 6 −PARTS LIST 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WARRANTY

OM-227 796 Page 1
SECTION 1 −SAFETY PRECAUTIONS FOR GMAW
WELDING GUNS −READ BEFORE USING
SR7_8/03
1-1. Symbol Usage
Means Warning! Watch Out! There are possible hazards with this
procedure! The possible hazards are shown in the adjoining symbols.
This group of symbols means Warning! Watch Out! Possible ELECTRIC SHOCK and HOT PARTS hazards.
Consult symbols and related instructions below for necessary actions to avoid the hazards.
Marks a special safety message.
Means NOTE; not safety related.
1-2. GMAW Gun Hazards
WARNING
PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH. KEEP CHILDREN
AWAY. PACEMAKER WEARERS KEEP AWAY UNTIL CONSULTING YOUR DOCTOR.
In welding, as in most jobs, exposure to certain hazards occurs. Welding is safe when precautions are taken. The
safety information given below is only a summary of the more complete safety information found in the wire feeder
and welding power source Owner’s Manuals. Read and follow all safety precautions.
HAVE ALL INSTALLATION, OPERATION, MAINTENANCE, AND REPAIR WORK PERFORMED ONLY BY
QUALIFIED PEOPLE.
GMAW WELDING can be hazardous.
ARC RAYS can burn eyes and skin.
1. Wear welding helmet with correct shade of filter.
2. Wear correct eye and body protection.
3. Cover exposed skin with spatter-resistant
clothing.
ELECTRIC SHOCK can kill.
1. Always wear dry insulating gloves.
2. Insulate yourself from work and ground.
3. Do not touch live electrode or electrical parts.
4. Repair or replace worn, damaged, or cracked
gun or cable insulation.
5. Turn off welding power source before changing
contact tip or gun parts.
6. Keep all covers and handle securely in place.
WELDING can cause fire or explosion.
1. Do not weld near flammable material.
2. Do not weld on closed containers.
3. Watch for fire; keep extinguisher nearby.
NOISE can damage hearing; SOME
APPLICATIONS, SUCH AS PULSING,
are noisy.
1. Check for noise level limits exceeding those
specified by OSHA.
2. Use approved ear plugs or ear muffs if noise level
is high.
3. Warn others nearby about noise hazard.
HOT SURFACES can burn skin.
1. Allow gun to cool before touching.
2. Do not touch hot metal.
3. Protect hot metal from contact by others.
FUMES AND GASES can be hazardous
to your health.
1. Keep your head out of the fumes.
2. Ventilate area, or use breathing device.
3. Read Material Safety Data Sheets (MSDSs) and
manufacturer’s instructions for material used.
WELDING WIRE can cause puncture
wounds.
1. Keep hands and body away from gun tip when
trigger is pressed.
BUILD UP OF GAS can injure or
kill
1. Shut off shielding gas supply when not in
use.
2. Always ventilate confined spaces or use
approved air-supplied respirator.

OM-227 796 Page 2
1-3. California Proposition 65 Warnings
Welding or cutting equipment produces fumes or gases which
contain chemicals known to the State of California to cause
birth defects and, in some cases, cancer. (California Health &
Safety Code Section 25249.5 et seq.)
Battery posts, terminals and related accessories contain lead
and lead compounds, chemicals known to the State of
California to cause cancer and birth defects or other
reproductiveharm. Wash hands after handling.
For Gasoline Engines:
Engine exhaust contains chemicals known to the State of
California to cause cancer, birth defects, or other reproductive
harm.
For Diesel Engines:
Diesel engine exhaust and some of its constituents are known
to the State of California to cause cancer, birth defects, and
other reproductive harm.
EMF INFORMATION
The following is a quotation from the General Conclusions Section of
the U.S. Congress, Office of Technology Assessment, Biological
Effects of Power Frequency Electric & Magnetic Fields −
Background Paper, OTA-BP-E-53 (Washington, DC: U.S.
Government Printing Office, May 1989): “. . . there is now a very large
volume of scientific findings based on experiments at the cellular
level and from studies with animals and people which clearly
establish that low frequency magnetic fields can interact with, and
produce changes in, biological systems. While most of this work is
of very high quality, the results are complex. Current scientific
understandingdoes not yet allow us to interpret the evidence in a
single coherent framework. Even more frustrating, it does not yet
allow us to draw definite conclusions about questions of possible risk
or to offer clear science-based advice on strategies to minimize or
avoid potential risks.”
To reduce magnetic fields in the workplace, use the following
procedures:
1. Keep cables close together by twisting or taping them.
2. Arrange cables to one side and away from the operator.
3. Do not coil or drape cables around the body.
4. Keep welding power source and cables as far away as practical.
5. Connect work clamp to workpiece as close to the weld as
possible.
About Pacemakers:
The above procedures are among those also normally
recommended for pacemaker wearers. Consult your doctor for
complete information.
Considerations About Welding And The Effects Of Low Frequency Electric And
Magnetic Fields
NOTE
mod10.1 4/93

OM-227 796 Page 3
SECTION 2 −SAFETY INFORMATION
Read all safety messages throughout this manual.
Obey all safety messages to avoid injury.
Learn the meaning of WARNING and CAUTION.
1 Safety Alert Symbol
2 Signal Word
WARNING means possible death
or serious injury can happen.
CAUTION means possible minor
injury or equipment damage can
happen.
3 Statement Of Hazard And
Result
4 Safety Instructions To Avoid
Hazard
5 Hazard Symbol (If Available)
6 Safety Banner
Read safety blocks for each
symbol shown.
7 NOTE
Special instructions for best
operation −not related to safety.
2
NOTE
ELECTRIC SHOCK can kill.
•Do not touch live electrical parts.
•Disconnect input power before
installing or servicing.
WARNING
READ SAFETY BLOCKS at start of
Section 3-1 before proceeding.
WARNING
5
4
6
7
1 2
CAUTION
MOVING PARTS can injure.
•Keep away from moving parts.
•Keep all panels and covers closed
when operating.
3
Turn Off switch when using high frequency.
SECTION 3 −INSTALLATION
3-1. Specifications
Air-Cooled Welding Gun For GMAW And FCAW Welding
Note: Using gasless flux cored wire reduces gun duty cycle.
804 466-A
M-25 Feeds .023 To .045 in (0.6 To 1.1 mm) Hard Or Flux Cored Wires
Duty Cycle Rating:
100%: 250 A With CO2Shielding Gas; 150 A With Mixed Gases
60%: 300 A With CO2Shielding Gas; 250 A With Mixed Gases
Weight With 15 ft (4.6 m) Power Cable: 6.0 lb (2.7 kg)
Identified With    On Power Cable

OM-227 796 Page 4
Exceeding duty cycle can
damage unit and void
warranty.
Overheating
0
15
A or V
OR
Reduce Duty Cycle
Minutes sduty1 5/95
3-2. Duty Cycle And Overheating
Duty Cycle is percentage of 10
minutes that gun can weld at
rated load without overheating.
0
10
Minutes
Definition
Continuous Welding
.023 To .045 in (0.6 To 1.1 mm)
Hard Or Flux Cored Wires
100% Duty Cycle At 200 Amperes
Using CO2
100% Duty Cycle At 150 Amperes
Using Mixed Gases
.023 To .045 in (0.6 To 1.1 mm) Hard Or Flux Cored Wires
60% Duty Cycle At 300 Amperes
Using CO2
60% Duty Cycle At 200 Amperes
Using Mixed Gases
6 Minutes Welding 4 Minutes Resting
See Section 3-1. Specifications for amperage rating and duty cycle.
3-3. Installing Gun
804 465-A
1 Gun Securing Knob
2 Gun End
Loosen knob. Insert gun end until it
bottoms against drive assembly.
Tighten knob.
3 Gun Trigger Plug
Insert into receptacle, and tighten
threaded collar.
4 Friction Terminals
Some applications will require
cutting off trigger plug and installing
0.250 female friction terminals onto
end of leads.
See wire feeder manual for
threading procedure.
13
2
4

OM-227 796 Page 5
SECTION 4 −OPERATION
4-1. Operating The Gun
Ref. 800 797-C
1 Trigger Switch
When pressed, energized wire
feeds and shielding gas flows.
1

OM-227 796 Page 6
SECTION 5 −MAINTENANCE & TROUBLESHOOTING
5-1. Removing Nozzle, Contact Tip, And Adapter, Changing Liner, And Cleaning Gun
Casing
804 466-A
Turn off welding power
source/wire feeder.
1 Nozzle
2 Contact Tip
3 Tip Adapter
4 Nozzle Adapter
Wire size stamped on tip −
check and match wire size.
Head
Tube
Tools Needed:
5/8, 7/16 in
Lay gun cable out
straight before
installing new liner.
Remove nozzle,
contact tip, and
adapter.
Unscrew and
remove liner.
Blow out
gun casing.
Cut off wire and
disconnect gun
from feeder.
7/16 in
3/4 in
(20 mm)
Liner
Stickout
Install
Liner
Thread wire according to
welding power source/wire
feeder manual.
Reassemble gun in
reverse order from
taking it apart.
1
4
3
2
5/8 in