Miller XMT 304 User manual

Processes
Multiprocess Welding
TM-180 670B September2001
Eff. w/Serial Number KG139511
Description
Arc Welding Power Source
XMT 304
(400 Volt Models)
R
Visit our website at
www.MillerWelds.com

dec_con1 10/95
Declaration of Conformity For
European Community (CE) Products
Manufacturer’s Name: Miller Electric Mfg. Co.
Manufacturer’s Address: 1635 W. Spencer Street
Appleton, WI 54914 USA
Declares that the product: XMT304
conforms to the following Directives and Standards:
Directives
Electromagnetic compatibility Directives: 89/336/EEC, 92/31/EEC
Low Voltage Directive: 73/23/EEC
Machinery Directives: 89/392/EEC, 91/368/EEC, 93/C 133/04, 93/68/EEC
Standards
Electromagnetic compatibility (EMC) Product standard for arc welding equipment:
EN50199: December 1995
Safety Requirements for Arc Welding Equipment part 1: EN 60974-1: 1989
Degrees of Protection provided by Enclosures (IP code): IEC 529: 1989
Insulation coordination for equipment within low-voltage systems:
Part 1: Principles, requirements and tests: IEC 664-1: 1992
European Contact: Danilo Fedolfi, Managing Director
MILLER Europe S.r.l.
Via Privata Iseo
20098 San Giuliano
Milanese, Italy
Telephone: [phone]
Fax: [phone]

TABLE OF CONTENTS
SECTION 1 – SAFETY PRECAUTIONS FOR SERVICING 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-1. Symbol Usage 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-2. Servicing Hazards 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-3. EMF Information 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 2 – DEFINITIONS 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1. Manufacturer’s Warning Label Definitions 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-2. Manufacturer’s Rating Labels 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-3. Symbols And Definitions 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 3 – INSTALLATION 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-1. Specifications 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2. Duty Cycle And Overheating 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-3. Volt-Ampere Curves 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-4. Selecting A Location 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-5. Weld Output Terminals And Selecting Cable Sizes 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-6. Remote 14 Receptacle Information 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-7. 110 Volt AC Duplex Receptacle 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-8. Electrical Service Guide 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-9. Connecting Input Power 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 4 – OPERATION 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-1. Front Panel Controls 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-2. Meter Functions 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-3. Mode Switch Settings 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-4. Lift-Arc Trigger Hold TIG 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 5 – THEORY OF OPERATION 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 6 – EXPLANATION OF ELECTRICAL PARTS 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 7 – PRE-POWER CHECKLIST 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7-1. Checking Unit Before Applying Power 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7-2. Output Diodes D1, D2 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7-3. Input Rectifier SR1 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7-4. Tank Capacitor C1 and Input Capacitors C3, C4 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7-5. IGBT Modules PM1, PM2 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7-6. Diodes D1, D2, D3, D4 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 8 – TROUBLESHOOTING 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-1. Troubleshooting Table 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-2. Voltmeter/Ammeter Help Displays Prior To Serial No. KG150087 30. . . . . . . . . . . . . . . . . . . . . .
8-3. Voltmeter/Ammeter Help Displays Effective With KG150087 31. . . . . . . . . . . . . . . . . . . . . . . . .
8-4. Troubleshooting Circuit Diagram For Welding Power Source Prior To KK104771 32. . . . . . . . .
8-5. Troubleshooting Circuit Diagram For Welding Power Source Eff. With KK104771 34. . . . . . . .
8-6. Waveforms For Sections 8-4 And 8-5 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-7. Control Board PC1 Testing Information (All Models – Use With Section 8-8) 37. . . . . . . . . . . . .
8-8. Control Board PC1 Test Point Values (All Models) 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-9. Display Board PC3 Testing Information (All Models – Use With Section 8-10) 40. . . . . . . . . . .
8-10. Display Board PC3 Test Point Values (All Models) 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-11. Interconnecting Board PC2 Testing Information (All Models) 42. . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 9 – MAINTENANCE 43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-1. Routine Maintenance 43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-2. Blowing Out Inside Of Unit 43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-3. Measuring Input Capacitor Voltage 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-4. Checking Bus Voltage Imbalance 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 10 – ELECTRICAL DIAGRAMS 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 11 – PARTS LIST FOR KG139511 AND FOLLOWING 68. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WARNING
This product, when used
for welding or cutting,
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.)

TM-180 670 Page 1XMT 304
SECTION 1 –SAFETY PRECAUTIONS FOR SERVICING
1-1. Symbol Usage
OM-180 670M - 1/00, safety_stm 5/97
Means Warning! Watch Out! There are possible hazards
with this procedure! The possible hazards are shown in
the adjoining symbols.
YMarks a special safety message.
.Means “Note”; not safety related.
This group of symbols means Warning! Watch Out! possible
ELECTRIC SHOCK, MOVING PARTS, and HOT PARTS hazards.
Consultsymbols and related instructions below for necessary actions
to avoid the hazards.
1-2. Servicing Hazards
YThe symbols shown below are used throughout this manual to
call attention to and identify possible hazards. When you see
the symbol, watch out, and follow the related instructions to
avoid the hazard.
YOnly qualified persons should service, test, maintain, and re-
pair this unit.
YDuring servicing, keep everybody, especially children, away.
ELECTRIC SHOCK can kill.
DDo not touch live electrical parts.
DTurn Off welding power source and wire feeder
and disconnect and lockout input power using
linedisconnect switch, circuit breakers, or by removing plug from re-
ceptacle,or stop engine before servicing unless the procedure spe-
cifically requires an energized unit.
DInsulateyourself from ground by standing or working on dry insulat-
ing mats big enough to prevent contact with the ground.
DDo not leave live unit unattended.
DIf this procedure requires an energized unit, have only personnel
familiarwith and following standard safety practices do the job.
DWhentesting a live unit, use the one-hand method. Do not put both
hands inside unit. Keep one hand free.
DDisconnect input power conductors from deenergized supply line
BEFORE moving a welding power source.
SIGNIFICANT DC VOLTAGE exists after removal of
input power on inverters.
DTurn Off inverter, disconnect input power, and discharge input
capacitorsaccording to instructions in Maintenance Section before
touchingany parts.
STATIC (ESD) can damage PC boards.
DPut on grounded wrist strap BEFORE handling
boards or parts.
DUse proper static-proof bags and boxes to
store, move, or ship PC boards.
FIRE OR EXPLOSION hazard.
DDo not place unit on, over, or near combustible
surfaces.
DDo not service unit near flammables.
FLYING METAL can injure eyes.
DWear safety glasses with side shields or face
shield during servicing.
DBe careful not to short metal tools, parts, or
wires together during testing and servicing.
HOT PARTS can cause severe burns.
DDo not touch hot parts bare handed.
DAllowcooling period before working on welding
gun or torch.
EXPLODING PARTS can cause injury.
DFailedparts can explode or cause other parts to
explodewhen power is applied to inverters.
DAlways wear a face shield and long sleeves
when servicing inverters.
SHOCK HAZARD from testing.
DTurn Off welding power source and wire feeder
or stop engine before making or changing me-
ter lead connections.
DUse at least one meter lead that has a self-
retainingspring clip such as an alligator clip.
DRead instructions for test equipment.
FALLING UNIT can cause injury.
DUse lifting eye to lift unit only, NOT running
gear, gas cylinders, or any other accessories.
DUse equipment of adequate capacity to lift and
supportunit.
DIf using lift forks to move unit, be sure forks are
long enough to extend beyond opposite side of
unit.
MOVING PARTS can cause injury.
DKeep away from moving parts such as fans.
DKeep all doors, panels, covers, and guards
closed and securely in place.

TM-180 670 Page 2 XMT 304
MOVING PARTS can cause injury.
DKeep away from moving parts.
DKeep away from pinch points such as drive
rolls.
MAGNETIC FIELDS can affect pacemak-
ers.
DPacemakerwearers keep away from servicing
areas until consulting your doctor.
OVERUSE can cause OVER-
HEATING.
DAllow cooling period; follow rated duty cycle.
DReduce current or reduce duty cycle before
startingto weld again.
DDo not block or filter airflow to unit.
H.F. RADIATION can cause interference.
DHigh-frequency(H.F.) can interfere with radio
navigation, safety services, computers, and
communicationsequipment.
DHave only qualified persons familiar with
electronicequipment install, test, and service
H.F. producing units.
DThe user is responsible for having a qualified electrician prompt-
ly correct any interference problem resulting from the installa-
tion.
DIf notified by the FCC about interference, stop using the
equipmentat once.
DHave the installation regularly checked and maintained.
DKeephigh-frequency source doors and panels tightly shut, keep
spark gaps at correct setting, and use grounding and shielding to
minimizethe possibility of interference.
READ INSTRUCTIONS.
DUse MILLER Testing Booklet (Part No. 150
853) when servicing this unit.
DConsultthe Owner’s Manual for welding safety
precautions.
DUse only genuine MILLER replacement parts.
1-3. EMF Information
Considerations About Welding And The Effects Of Low Frequency
Electric And Magnetic Fields
Weldingcurrent, as it flows through welding cables, will cause electro-
magnetic fields. There has been and still is some concern about such
fields. However, after examining more than 500 studies spanning 17
years of research, a special blue ribbon committee of the National
Research Council concluded that: “The body of evidence, in the
committee’s judgment, has not demonstrated that exposure to power-
frequency electric and magnetic fields is a human-health hazard.”
However, studies are still going forth and evidence continues to be
examined.Until the final conclusions of the research are reached, you
may wish to minimize your exposure to electromagnetic fields when
weldingor cutting.
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 your body.
4. Keep welding power source and cables as far away from opera-
tor as practical.
5. Connect work clamp to workpiece as close to the weld as possi-
ble.
About Pacemakers:
Pacemakerwearers consult your doctor first. If cleared by your doctor,
thenfollowing the above procedures is recommended.

TM-180 670 Page 3XMT 304
SECTION 2 –DEFINITIONS
2-1. Manufacturer’s Warning Label Definitions
Warning! Watch Out! There are
possible hazards as shown by the
symbols.
1 Electric shock from welding
electrode or wiring can kill.
1.1 Wear dry insulating gloves.
Do not touch electrode with
bare hand. Do not wear wet or
damaged gloves.
1.2 Protect yourself from electric
shock by insulating yourself
from work and ground.
1.3 Disconnect input plug or
power before working on
machine.
2 Breathing welding fumes can
be hazardous to your health.
2.1 Keep your head out of the
fumes.
2.2 Use forced ventilation or local
exhaust to remove the fumes.
2.3 Use ventilating fan to remove
fumes.
3 Welding sparks can cause
explosion or fire.
3.1 Keep flammables away from
welding. Do not weld near
flammables.
3.2 Welding sparks can cause
fires. Have a fire extinguisher
nearby, and have a
watchperson ready to use it.
3.3 Do not weld on drums or any
closed containers.
4 Arc rays can burn eyes and
injure skin.
4.1 Wear hat and safety glasses.
Use ear protection and button
shirt collar. Use welding
helmet with correct shade of
filter. Wear complete body
protection.
5 Become trained and read the
instructions before working on
the machine or welding.
6 Do not remove or paint over
(cover) the label.
1/96
1 1.1 1.2 1.3
3 3.1 3.2 3.3
4 4.1 +
2 2.1 2.2
+
+
56
+
2.3
S-179 310

TM-180 670 Page 4 XMT 304
> 60 s
V
S-179 190-A
V
V
1 Warning! Watch Out! There
are possible hazards as
shown by the symbols.
2 Electric shock from wiring can
kill.
3 Disconnect input plug or
power before working on
machine.
4 Hazardous voltage remains
on input capacitors after
power is turned off. Do not
touch fully charged
capacitors.
5 Always wait 60 seconds after
power is turned off before
working on unit, OR
6 Check input capacitor voltage,
and be sure it is near 0 before
touching any parts.
4/96
1234 5 6
S-179 304-A
1 Warning! Watch Out! There
are possible hazards as
shown by the symbols.
2 When power is applied failed
parts can explode or cause
other parts to explode.
3 Flying pieces of parts can
cause injury. Always wear a
face shield when servicing
unit.
4 Always wear long sleeves and
button your collar when
servicing unit.
5 After taking proper
precautions as shown,
connect power to unit.
4/96
123 4 5
S-179 309-A
∠= <60°
∠
1 Warning! Watch Out! There
are possible hazards as
shown by the symbols.
2 Falling equipment can cause
injury and damage to unit.
3 Always lift and support unit
using both handles. Keep
angle of lifting device less
than 60 degrees.
4 Use a proper cart to move
unit.
5 Do not use one handle to lift
or support unit.
1/96
1
2345

TM-180 670 Page 5XMT 304
2-2. Manufacturer’s Rating Labels

TM-180 670 Page 6 XMT 304
2-3. Symbols And Definitions
AAmperage Panel Alternating
Current(AC) VVoltage
Output Circuit Breaker Remote On
Off Gas Tungsten Arc
Welding Negative Voltage Input
Direct Current
(DC) Positive Inductance Protective Earth (Ground)
Constant Current Constant Voltage Foot Control Line Connection
Arc Force Shielded Metal Arc
Welding (SMAW) Gas Metal Arc Welding (GMAW)
Three Phase Static
Frequency Con-
verter-
Transformer-
Rectifier
U0Rated No Load
Voltage (Average) U1Primary Voltage U2Conventional Load Voltage XDuty Cycle
Hz Hertz IP Degree Of
Protection I2Rated Welding Current %Percent
Pulsed Lift-Arc Trigger
Hold Operation
(GTAW) Single Phase Three Phase
I1max Rated Maximum
Supply Current I1eff Maximum Effective Supply Current Increase Lift-Arc Operation (GTAW)

TM-180 670 Page 7XMT 304
SECTION 3 –INSTALLATION
3-1. Specifications
Rated Welding
Output Voltage Range Amperage Range
Maximum
Open-Circuit IP Rating
Amperes Input
at Rated Load
Output 50/60 Hz
Output Range Range Voltage DC 400 V KVA KW
300 A @
32 Volts DC,
60% Duty Cycle 10 –35 5 –400 90 23 17.0
(0.15*) 12.4 (0.09*) 11.5 (0.04*)
*While idling
6 Minutes Welding 4 Minutes Resting
3-2. Duty Cycle And Overheating
Duty Cycle is percentage of 10 min-
utes that unit can weld at rated load
withoutoverheating.
If unit overheats, output stops, a
Help message is displayed (see
Section8-3), and cooling fan runs.
Wait fifteen minutes for unit to cool.
Reduceamperage or duty cycle be-
fore welding.
YExceeding duty cycle can
damage unit and void war-
ranty.
60% Duty Cycle
Overheating
0
15
A
OR
Reduce Duty Cycle
Minutes
Ref. SA-178 651

TM-180 670 Page 8 XMT 304
3-3. Volt-Ampere Curves
va_curve1 4/95 –SA-178 652 / SA-178 653
Volt-amperecurves show minimum
and maximum voltage and amper-
age output capabilities of unit.
Curves of other settings fall be-
tween curves shown.
A. CC Mode B. CV Mode
ARC CONTROL

TM-180 670 Page 9XMT 304
3-4. Selecting A Location
loc_2 3/96 - ST-801 192
1 LiftingHandles
Use handles to lift unit.
2 Hand Cart
Use cart or similar device to move
unit.
3 Plate Label
Use label to determine input power
needs.
4 Line Disconnect Device
Locate unit near correct input
power supply.
YSpecial installation may be
required where gasoline or
volatileliquids are present –
see NEC Article 511 or CEC
Section20.
24 in
(610 mm)
17 in
(432 mm)
12-1/2 in
(318 mm)
Movement
1
12
YDo not move or operate unit
where it could tip.
Location
4
Dimensions And Weight
18 in
(460 mm)
18 in
(460 mm)
87 lb (39.5 kg)
3

TM-180 670 Page 10 XMT 304
3-5. Weld Output Terminals And Selecting Cable Sizes
YARC WELDING can cause Electromagnetic Interference.
To reduce possible interference, keep weld cables as short as possible, close together, and down low, such as on the floor.
Locatewelding operation 100 meters from any sensitive electronic equipment. Be sure this welding machine is installed
and grounded according to this manual. If interference still occurs, the user must take extra measures such as moving
the welding machine, using shielded cables, using line filters, or shielding the work area.
Total Cable (Copper) Length In Weld Circuit Not Exceeding*
100 ft (30 m)**
Or Less 150 ft (45 m) 200 ft (60 m) 250 ft (70 m) 300 ft (90 m) 350 ft (105 m) 400 ft (120 m)
Weld Output
Terminals Welding Amperes
10 –60%
Duty
Cycle
60 –100%
Duty
Cycle 10 –100% Duty Cycle
100 4 (20)** 4 (20) 4 (20) 3 (30) 2 (35) 1 (50) 1/0 (60) 1/0 (60)
150 3 (30)** 3 (30) 2 (35) 1 (50) 1/0 (60) 2/0 (70) 3/0 (95) 3/0 (95)
200 3 (30) 2 (35) 1 (50) 1/0 (60) 2/0 (70) 3/0 (95) 4/0 (120) 4/0 (120)
250 2 (35) 1 (50) 1/0 (60) 2/0 (70) 3/0 (95) 4/0 (120) 2-2/0
(2x70) 2-2/0 (2x70)
300 1 (50) 1/0 (60) 2/0 (70) 3/0 (95) 4/0 (120) 2-2/0
(2x70) 2-3/0 (2x95) 2-3/0 (2x95)
350 1/0 (60) 2/0 (70) 3/0 (95) 4/0 (120) 2-2/0
(2x70) 2-3/0 (2x95) 2-3/0 (2x95) 2-4/0 (2x120)
+–400 1/0 (60) 2/0 (70) 3/0 (95) 4/0 (120) 2-2/0
(2x70) 2-3/0 (2x95) 2-4/0 (2x120) 2-4/0 (2x120)
Output Receptacles
500 2/0 (70) 3/0 (95) 4/0 (120) 2-2/0
(2x70) 2-3/0 (2x95) 2-4/0 (2x120) 3-3/0 (3x95) 3-3/0 (3x95)
600 3/0 (95) 4/0 (120) 2-2/0
(2x70) 2-3/0 (2x95) 2-4/0 (2x120) 3-3/0 (3x95) 3-4/0 (3x120) 3-4/0 (3x120)
*Weld cable size (AWG) is based on either a 4 volts or less drop or a current density of at least 300 circular mils per ampere.
**( ) = mm2for metric use. S-0007-E

TM-180 670 Page 11XMT 304
3-6. Remote 14 Receptacle Information
Socket* Socket Information
24 VOLTS AC A24 volts ac. Protected by circuit breaker CB2.
AJ
KI
24 VOLTS AC
BContact closure to A completes 24 volts ac con-
tactor control circuit.
BI
CLNH 115 VOLTS AC I115 volts ac. Protected by circuit breaker CB1.
C
DMG
EF
115 VOLTS AC
JContact closure to I completes 115 volts ac con-
tactor control circuit.
COutput to remote control; 0 to +10 volts dc, +10
volts dc in MIG mode.
REMOTE
OUTPUT DRemotecontrol circuit common.
CONTROL E0 to +10 volts dc input command signal from re-
mote control.
A/V HVoltage feedback; +1 volt dc per 10 output recep-
tacle volts.
A/V
AMPERAGE
VOLTAGE
FCurrent feedback; +1 volt dc per 100 amperes.
ST-801 192 VOLTAGE MCC/CV select
GCircuit common for 24 and 115 volts ac circuits.
GND K Chassis common.
*The remaining sockets are not used.
3-7. 110 Volt AC Duplex Receptacle
Ref. ST-801 245-A
1 110 V 7 A AC Receptacle
Power is shared between duplex
receptacle and Remote 14 recep-
tacle (see Section 3-6).
2 Circuit Breaker CB1
3 Circuit Breaker CB2
CB1 protects 110 volt ac portion of
duplex receptacle and Remote 14
receptaclefrom overload.
CB2 protects 24 volt ac portion of
Remote 14 receptacle from
overload.
Press button to reset breaker.
2 3
1

TM-180 670 Page 12 XMT 304
3-8. Electrical Service Guide
Actual input voltage should not exceed ±10% of indicated required input voltage. If
actual input voltage is outside of this range, output may not be available.
NOTE
Input Voltage 400 (Three Phase Only)
Input Amperes At Rated Output 17.0
Max Recommended Standard Fuse Or Circuit Breaker Rating In Amperes 30
Reference: 1996 National Electrical Code (NEC). S-0092J
“3-9. Connecting Input Power
YDisconnect and lockout/tag-
out input power before con-
necting input conductors
from unit.
YHave only qualified persons
make this installtion.
Check input voltage available at
site.
1 Line Disconnect Device
2 Input And Grounding
Conductors
Select type and size of overcurrent
protection using Section 3-8.
YAlways connect green/yel-
low wire to supply ground-
ing terminal, never to a line
terminal.
Input_9_99 / Ref. ST-144 221 / ST-801 192
Tools Needed:
L1
2
1
2
L2
L3
YAlways connect grounding
conductor first.
= GND/PE Green/Yellow
Install conductors into a deenergized
line dissconnect device.

TM-180 670 Page 13XMT 304
SECTION 4 –OPERATION
4-1. Front Panel Controls
1 Power On/Off Switch
.The fan motor is thermostatically
controlledand only runs when cooling is
needed.
2 Voltmeter (see Section 4-2)
3 Ammeter (see Section 4-2)
4 Voltage/Amperage Adjustment Control
5 Mode Switch
The Mode switch setting determines both the
process and output On/Off control (see Sec-
tion 4-3. Source of control (panel or remote)
for the amount of output is selected on the
Voltage/AmperageControl switch.
For Air Carbon Arc (CAC-A) cutting and
gouging,place switch in Stick position. For
best results, place Inductance/Dig control in
the maximum position.
6 Voltage/Amperage Control Switch
For front panel control, place switch in Panel
position.
For remote control, make connections to Re-
mote 14 receptacle, and place switch in
Remote position. In most modes, remote
controlis a percent of the Voltage/Amperage
Adjustment control setting (the value se-
lected on Voltage/Amperage Adjustment
control is maximum available on remote). In
the MIG mode, remote control provides full
rangeof unit output regardless of V/A Adjust
control setting.
7 Inductance/Dig Control
Control adjusts Dig when a Stick (SMAW)
weldingposition is selected on mode switch.
When set lower, short-circuit amperage at
low arc voltage is the same as normal welding
amperage.
When set higher, short-circuit amperage is in-
creased at low arc voltage to assist with arc
starts as well as reduce sticking while weld-
ing (see volt-ampere curves in Section 3-3).
Select setting best suited for application.
Control adjusts inductance when a MIG
(GMAW) position is selected on the mode
switch. Inductance determines the “wetness”
of the weld puddle. When set higher, “wet-
ness”(puddle fluidity) increases.
Whenpulsed MIG, or one of the TIG (GTAW)
processes is selected, this control is not func-
tional.
234
56
1
7
ST-179 275

TM-180 670 Page 14 XMT 304
4-2. Meter Functions
The meters display the actual weld output values for approximately three seconds
after the arc is broken.
NOTE
Mode Meter Reading At Idle Meter Reading While Welding
Lift-Arc Trigger
Hold TIG (GTAW)
VA
Blank Preset Amps
85 Actual Volts Actual Amps
VA
10.3 85
TIG (GTAW) Blank Preset Amps
VA
85 Actual Volts Actual Amps
VA
10.3 85
MIG (GMAW) Preset Volts Blank
VA
24.5 Actual Volts Actual Amps
VA
24.5 250
Pulsed MIG
(GMAW-P) Pulse Display Pulse Display
VA
PPP PPP Actual Volts Actual Amps
VA
24.5 250
Remote
Control SMAW Blank Preset Amps
VA
85 Actual Volts Actual Amps
VA
24.5 85
Panel Control
SMAW Actual Volts (OCV) Preset Amps
VA
85.0 85 Actual Volts Actual Amps
VA
24.5 85

TM-180 670 Page 15XMT 304
4-3. Mode Switch Settings
The SMAW modes provide the Adaptive Hot Startfeature, which automatically
increases the output amperage at the start of a weld should the start require it. This
eliminates electrode sticking at arc start.
NOTE
Mode Output Control
Lift-Arc Trigger
Hold TIG (GTAW)
Select: or Amp
Requires: Control
TIG (GTAW) With
HF Unit,
Pulsing Device,
Or Remote Control
Select: or Amp
Requires: Control
MIG (GMAW) Select: or Volt
Requires: Feeder
Pulsed MIG
(GMAW-P)
(Requires an
external
pulsing device.)
Select: Volt
Requires: Feeder or Control
Remote
Control SMAW
Select: or Amp
Requires: Control
Panel Control
SMAW
Select: or Amp
Weld

TM-180 670 Page 16 XMT 304
4-4. Lift-Arc Trigger Hold TIG
1 TIG Electrode
2 Workpiece
.Procedure requires:
Start sequence:
•Touch tungsten electrode to
workpiece at weld start point.
•Momentarily depress output
switch.
•Slowly lift electrode. An arc will
form when electrode is lifted.
•To stop welding, momentarily
depress output switch and out-
put will shut off.
Note: If output switch is momen-
tarily depressed and tungsten is
not touching workpiece:
Do not touch tungsten to work.
Output will shut off in 3 seconds.
Start sequence over.
1
1 –2
Seconds
“Touch”
Do NOT Strike Like A Match!
2
Ref. S-156 279
control