Miller Electric TM-353E User Manual

TM-353E January 2001

Eff. w/Serial Number JJ339876

Processes

TIG (GTAW) Welding

Stick (SMAW) Welding

Description

Arc Welding Power Source

R

Syncrowave 250

Visit our website at

www.MillerWelds.com

60 Hz, 50 Hz

TABLE OF CONTENTS

1. Safety Precautions – Read Before Using 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.1 Symbol Usage 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2 Servicing Hazards 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.3 EMF Information 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 2 – DEFINITIONS 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-1. Warning Label Definitions 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-2. Rating Label For CE Products 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-3. Symbols And Definitions 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 3 – INSTALLATION 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-1. Specifications 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-2. Volt-Ampere Curves 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-3. Duty Cycle And Overheating 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-4. Selecting A Location 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-5. Dimensions And Weights 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-6. Tipping 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-7. Weld Output Terminals And Selecting Cable Sizes 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-8. Remote 14 Receptacle 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-9. 115 Volts AC Duplex Receptacle And Shielding Gas Connections 10. . . . . . . . . . . . . . . . . . . . . .

3-10.Electrical Service Guide 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-11.Placing Jumper Links And Connecting Input Power 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 4 – OPERATION 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-1. Controls 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-2. Output Selector Switch 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-3. Meters 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-4. Crater Time Controls 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-5. Spot Time Controls 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-6. AC Balance Control 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-7. Amperage Adjustment Controls 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-8. Output (Contactor) Control Switch 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-9. Arc Controls 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-10.Postflow Time Control 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-11.High Frequency Controls 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-12.Preflow Time Control (Optional) 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 5 – THEORY OF OPERATION 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 6 – TROUBLESHOOTING 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-1. Troubleshooting Table 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-2. Troubleshooting Circuit Diagram For Welding Power Source 26. . . . . . . . . . . . . . . . . . . . . . . . . .

6-3. Waveforms For Section 6-2 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-4. Control Board PC1 Testing Information (Use With Section 6-5) 30. . . . . . . . . . . . . . . . . . . . . . . .

6-5. Control Board PC1 Test Point Values 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-6. Remote Board PC2 Testing Information (Use With Section 6-7) 33. . . . . . . . . . . . . . . . . . . . . . . .

6-7. Remote 14 Filter Board PC2 Test Point V alues (Use With Section 6-2 And Section 6-6) 34. . . .

6-8. Meter Calibration 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-9. Input Voltage Labels And Connections 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 7 – MAINTENANCE 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-1. Routine Maintenance 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-2. Circuit Breaker CB1 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-3. Fuses F1 And F2 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-4. Adjusting Spark Gaps 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 8 – HIGH FREQUENCY (HF) 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-1. Welding Processes Using HF 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-2. Sources Of HF Radiation From Incorrect Installation 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-3. Correct Installation 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 9 – ELECTRICAL DIAGRAMS 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 10 – PARTS LIST 68. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TM-353D

Declaration of Conformity For

European Community (CE) Products

NOTE

Manufacturer’s Name: Miller Electric Mfg. Co.

Manufacturer’s Address: 1635 W. Spencer Street

This information is provided for units with CE certification (see rating label on unit.)

Appleton, WI 54914 USA

Declares that the product: Syncrowave 250

conforms to the following Directives and Standards:

Directives

Low Voltage Directive: 73/23/EEC

Machinery Directives: 89/392/EEC, 91/368/EEC, 93/C 133/04, 93/68/EEC

Electromagnetic Capability Directives: 89/336, 92/31/EEC

Standards

Safety Requirements for Arc Welding Equipment part 1: EN 60974-1: 1990

Arc Welding Equipment Part 1: Welding Power Sources: IEC 974-1

(April 1995 – Draft revision)

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

Electromagnetic compatibility (EMC) Product standard for arc welding equipment:

EN50199: August 1995

European Contact: Mr. Luigi Vacchini, Managing Director

MILLER Europe S.P.A.
Via Privata Iseo
20098 San Giuliano
Milanese, Italy

Telephone: [phone]

Fax: [phone]

dec_con1 10/95

SECTION 1 – SAFETY PRECAUTIONS FOR SERVICING

1-1. Symbol Usage

safety_stm1 4/95

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, MOVING P ARTS,
and HOT P ARTS hazards. Consult symbols and related instructions below for necessary actions to
avoid the hazards.

Y Marks a special safety message.

. Means NOTE; not safety related.

1-2. Servicing Hazards

WARNING

The 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.

Only qualified persons should service, test, maintain, and repair this unit.
During servicing, keep everybody, especially children, away.

ELECTRIC SHOCK can kill.

1. Do not touch live electrical parts.

2. Stop engine or turn OFF welding power source and
wire feeder, and disconnect and lockout input
power using line disconnect switch, circuit
breakers, or by removing plug from receptacle
before servicing unless the procedure specifically
requires an energized unit.

3. Insulate yourself from ground by standing or
working on dry insulating mats big enough to
prevent contact with the ground.

4. Do not leave live unit unattended.

5. When testing a live unit, use the one-hand method.
Do not put both hands inside unit. Keep one hand
free.

6. Disconnect input power conductors from
deenergized supply line BEFORE moving a
welding power source.

SIGNIFICANT DC VOLTAGE exists after
removal of input power on inverters.

7. Turn Off inverter, disconnect input power, and
discharge input capacitors according to
instructions in Maintenance Section before
touching any parts.

STATIC ELECTRICITY can damage
parts on circuit boards.

1. Put on grounded wrist strap BEFORE handling
boards or parts.

2. Use proper static-proof bags to store, move, or ship
PC boards.

FIRE OR EXPLOSION can result from
placing unit on, over, or near
combustible surfaces.

1. Do not place unit on, over, or near combustible
surfaces.

2. Do not service unit near flammables.

FLYING PIECES OF METAL or DIRT can
injure eyes.

1. Wear safety glasses with side shields or face shield
during servicing.

2. Be careful not to short metal tools, parts, or wires
together during testing and servicing.

HOT PARTS can cause severe burns.

1. Do not touch hot parts bare handed.

2. Allow cooling period before servicing welding gun
or torch.

EXPLODING PARTS can cause injury.

1. Failed parts can explode or cause other parts to
explode when power is applied to inverters.

2. Always wear a face shield and long sleeves when
servicing inverters.

ELECTRIC SHOCK HAZARD from
incorrect use of test equipment.

1. Turn Off welding power source and wire feeder or
stop engine before making or changing meter lead
connections.

2. At least one meter lead should be a self-retaining
spring clip such as an alligator clamp.

3. Read instructions for test equipment.

HIGH-FREQUENCY RADIATION can
interfere with radio navigation, safety
services, computers, and
communications equipment.

1. Have only qualified persons familiar with electronic
equipment perform this installation.

2. The user is responsible for having a qualified
electrician promptly correct any interference
problem resulting from the installation.

3. If notified by the FCC about interference, stop using
the equipment at once.

4. Have the installation regularly checked and
maintained.

5. Keep high-frequency source doors and panels
tightly shut, keep spark gaps at correct setting, and
use grounding and shielding to minimize the
possibility of interference.

TM-353 Page 1Syncrowave 250

FALLING EQUIPMENT can cause
serious personal injury and equipment
damage.

1. Use lifting eye to lift unit only, NOT running gear,
gas cylinders, or any other accessories.

2. Use equipment of adequate capacity to lift unit.

MAGNETIC FIELDS FROM HIGH
CURRENTS can affect pacemaker
operation.

1. Pacemaker wearers keep away from servicing
areas until consulting your doctor.

MOVING PARTS can cause injury.

1. Keep away from moving parts such as fans.

2. Keep all doors, panels, covers, and guards closed
and securely in place.

1-3. EMF Information

MOVING PARTS can cause injury.

1. Keep away from moving parts.

2. Keep away from pinch points such as drive rolls.

OVERUSE can cause OVERHEATED
EQUIPMENT.

1. Allow cooling period.

2. Reduce current or reduce duty cycle before
starting to weld again.

3. Follow rated duty cycle.

READ INSTRUCTIONS.

1. Use MILLER Testing Booklet (Part No. 150 853)
when servicing this unit.

2. Consult the Owner ’s Manual for welding safety
precautions.

3. Use only genuine MILLER replacement parts.

Considerations About Welding And The Effects Of Low Frequency
Electric And Ma g netic Fields

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 understanding does not yet allow us to
interpret the evidence in a single coherent framework. Even more
frustrating, i t 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 also recommended for pacemaker
wearers. Consult your doctor for complete information.

TM-353 Page 2 Syncrowave 250

SECTION 2 – DEFINITIONS

2-1. Warning Label Definitions

1 1.1 1.2

2

3 3.1 3.2 3.3

4 4.1

2.1

+

2.2

2.3

+

+

1.3

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. Don’t weld near
flammables.

3.2 Welding sparks can cause
fires. Have a fire extinguisher
nearby and have a watch
person 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.

5 6

+

S-176 254-A

TM-353 Page 3Syncrowave 250

2-2. Rating Label For CE Products

1

1

50 Hz

1

= 80V

U

0

= 80V

U

0

U

= 220 I

1

U

= 380 I

1

U

= 415 I

1

ISO/IEC 974-1

7A/10.2V 310A/22.4V

X 25% 60% 100%
I
U

5A/20.2V 310A/32.4V

X 25% 60% 100%
I
U

310A 200A 155A

2

22.4V 18V 16.2V

2

310A 200A 155A

2

32.4V 28V 26.2V

2

= 117.2A I

1max

= 72.2A I

1max

= 63.8A I

1max

1Eff

1Eff

1Eff

= 59A
= 36A

= 32A

IP 21S

S-178 813-A

TM-353 Page 4 Syncrowave 250

2-3. Symbols And Definitions

NOTE

A

V

Some symbols are found only on CE products.

Amperes Panel–Local

Volts

Output Circuit Breaker Remote Temperature

Protective Earth

(Ground)

Postflow Timer Preflow Timer

Gas (Supply) Gas Input Gas Output

On Off Percent Direct Current

Do Not Switch

While Welding

Alternating Current

Gas Tungsten Arc

Welding (GT AW)

Arc Force (DIG) Spot Timer

High Frequency -

Start

High Frequency -

Continuous

Shielded Metal Arc

Welding (SMAW)

High Frequency

Increase/Decrease

Of Quantity

Input

U

I

1

IP

S

Balance Control Maximum Cleaning

Electrode

Negative

Voltage (A verage)

0

Rated No Load

Primary Current

Degree Of
Protection

Electrode Work Thickness Gauge Spark Gap

Seconds

U

I

I

1eff

1

2

Maximum

Penetration

Crater Time Meter Single-Phase

Primary Voltage

Rated Welding

Current

Maximum Effective

Supply Current

U

X

I

1max

Conventional Load

2

Rated Maximum

Supply Current

Voltage

Duty Cycle

1

Hz

Electrode Positive

Line Connection

Single-Phase

1

Combined AC/DC

Power Source

Hertz

TM-353 Page 5Syncrowave 250

3-1. Specifications

Rated

Rated

Welding Output

NEMA Class II

(40) – 250

Amperes, 30 Volts

AC, 40% Duty

Cycle

*While idling
**Power Factor Correction

Rated

Welding

PFC

Output

NEMA
Class I

(60) – 200

Amperes,

28 Volts

AC, 60%

Duty Cycle
*While idling

**Power Factor Correction

PFC85(4.6*)77(4.2*)74(4*)65(3.5*)45(2.4*)41(2.2*)37(2*)33(1.8*)30(1.6*)17(0.9*)

With
PFC55(57*)64(51*)48(49*)48(49*)37(30*)34(27*)24(25*)48(49*)19(20*)11(11*)

PFC**

No

PFC
With

PFC

200V220V230V260V380V415V460V520V575

**

No

SECTION 3 – INSTALLATION

Amperes Input at AC Balanced

Rated Load Output,

50/60 Hz, Single-Phase

200 V 230 V 460 V 575 V

106

(4.6*)

76 66 33 26 15.2 11.4

92

(4*)

46

(2*)

37

(1.6*)21(0.89*)

Amperes Input at AC Balanced

Rated Load Output,

50/60 Hz, Single-Phase

KVA KW

11.4

(0.68*)

V

KVA KW

Amp

Range

5–310 A 80 V 21

8.3

(0.7*)

8.3

(0.6*)

Max

OCV

Amp

Range

5–310 A 80 V 21

Rating

Max

OCVIPRating

IP

3-2. Volt-Ampere Curves

A. DC Mode

The volt-ampere curves show the
minimum and maximum voltage
and amperage output capabilities of
the welding power source. Curves
of other settings fall between the
curves shown.

B. AC Mode

ssb1.1 10/91 – SB-116 199 / SB-116 200

TM-353 Page 6 Syncrowave 250

3-3. Duty Cycle And Overheating

40% Duty Cycle At 250 Amperes (60 Hz Models Only)

4 Minutes Welding 6 Minutes Resting

Duty Cycle is percentage of 10 mi n ­utes that unit can weld at rated load
without overheating.

If unit overheats, thermostat opens,
output stops, light goes on (CE
models only), and cooling fan runs.
Wait fifteen minutes for unit to cool.
Reduce amperage or duty cycle be­fore welding.

Y Exceeding duty cycle can

damage unit and void
warranty.

Overheating

60% Duty Cycle At 200 Amperes

6 Minutes Welding 4 Minutes Resting

0

15

Minutes

A

OR

Reduce Duty Cycle

duty1 4/95 / SB-116 198

TM-353 Page 7Syncrowave 250

3-4. Selecting A Location

Movement

Location And Airflow

3

5

1 Lifting Eye
2 Lifting Forks
Use lifting eye or lifting forks to

move unit.

1

OR

2

6

4

18 in (460

mm)

If using lifting forks, extend forks
beyond opposite side of unit.

3 Rating Label (Non CE Models

Only)

4 Rating Label (CE Models

Only, See Section 2-2)

Use rating label to determine input
power needs. CE label located on
rear panel.

5 Plate Label (CE Models Only)
6 Line Disconnect Device
Locate unit near correct input pow-

er supply.

Y Special installation may be

required where gasoline or
volatile liquids are present –
see NEC Article 511 or CEC
Section 2 0 .

18 in (460

mm)

3-5. Dimensions And Weights

A

B

C

Front

ST-800 402 / ST-117 264-F

Dimensions

Height 30-3/4 in (781 mm)

D

E

F

F

G

Width 19-3/4 i n (502 mm)

Length 27-1/2 i n (698 mm)

A 27 in (686 mm)
B 26 in (661 mm)
C 25-1/4 i n (642 mm)
D 1-1/2 in (38 mm)
E 1-1/8 (29 mm)
F 17-7/8 (454 mm)
G 19-1/4 (489 mm)
H 1/2 in (13 mm) Dia

6 Holes

H

TM-353 Page 8 Syncrowave 250

ST-154 792-B

Weight

355 lbs (161 kg)

3-6. Tipping

Y Be careful when placing or

moving unit over uneven
surfaces.

3-7. Weld Output Terminals And Selecting Cable Sizes

Y ARC 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.
Locate welding 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

Weld Output

Terminals

100 ft (30 m) Or Less

Welding

Amperes

100 4 4 4 3 2 1 1/0 1/0

150 3 3 2 1 1/0 2/0 3/0 3/0

200 3 2 1 1/0 2/0 3/0 4/0 4/0

250 2 1 1/0 2/0 3/0 4/0 2-2/0 2-2/0

300 1 1/0 2/0 3/0 4/0 2-2/0 2-3/0 2-3/0

10 – 60%

Duty

Cycle

60 – 100%

Duty

Cycle

150 ft

(45 m)

200 ft

(60 m)

250 ft

(70 m)

300 ft

(90 m)

10 – 100% Duty Cycle

350 ft

(105 m)

400 ft

(120 m)

350 1/0 2/0 3/0 4/0 2-2/0 2-3/0 2-3/0 2-4/0

ElectrodeWork

ST-154 795-C

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. Contact your dis­tributor for the mm2 equivalent weld cable sizes. S-0007-E

400 1/0 2/0 3/0 4/0 2-2/0 2-3/0 2-4/0 2-4/0

500 2/0 3/0 4/0 2-2/0 2-3/0 2-4/0 3-3/0 3-3/0

TM-353 Page 9Syncrowave 250

3-8. Remote 14 Receptacle

F

Socket* Socket Information

A 24 volts ac.

AJ

K

B

L

C

D

*The remaining sockets are not used.

I

NH

M

G

F

E

ST-154 795-C

B Contact closure to A completes 24 volts ac contactor control

C Command reference; 0 to +10 volts dc output to remote control.

D Remote control circuit common.

A

E 0 to +10 volts dc input command signal from remote control.

K Chassis common.

circuit.

3-9. 115 Volts AC Duplex Receptacle And Shielding Gas Connections

Y Turn Off power before

connecting to receptacle.

1 115 V AC Receptacle

5

6

1 7

4

Receptacle is protected from over­load by circuit breaker CB1 (see
Section 7-2).

2 Gas Valve In Fitting
3 Gas Valve Out Fitting
Fittings have 5/8-18 right-hand

threads
4 Cylinder Valve
Open valve slightly so gas flow

blows dirt from valve. Close valve.
5 Regulator/Flow Gauge
6 Flow Adjust
Typical flow rate is 20 cfh (cubic feet

per hour) (9.4 L/min)
7 High Frequency Control (see

Section 4-1)

3 2

Ref. ST-154 795-C / Ref. ST-157 858

TM-353 Page 10 Syncrowave 250

3-10. Electrical Service Guide

NOTE

60 Hertz Models

Input Voltage
Input Amperes At Rated Output
Max Recommended Standard Fuse Or Circuit

Breaker Rating In Amperes
Min Input Conductor Size In AWG/Kcmil
Max Recommended Input Conductor Length

In Feet (Meters)
Min Grounding Conductor Size In AWG/Kcmil

Reference: 1996 National Electrical Code (NEC) S-0092-J

50 Hertz Models Without Power Factor Correction

Input Voltage
Input Amperes At Rated Output

All values calculated at 60% duty cycle.

Without Power Factor

Correction

200 230 460 575 200 230 460 575

85 74 37 30 55 48 24 19

125 110 60 45 80 70 35 30

4 6 10 10 8 8 12 14

173

(53)

6 6 10 10 8 8 12 14

220 260 380 415 520 220 380 415

77 65 45 41 33 64 37 34

158
(48)

291
(89)

455

(139)

With Power Factor Correction

86

(26)

114

(35)

186
(58)

189
(48)

With Power Factor

Correction

Max Recommended Standard Fuse Or Circuit
Breaker Rating In Amperes

Min Input Conductor Size In AWG/Kcmil
Max Recommended Input Conductor Length

In Feet (Meters)
Min Grounding Conductor Size In AWG/Kcmil

Reference: 1996 National Electrical Code (NEC) S-0092-J

125 100 70 60 50 90 60 50

6 6 8 8 10 6 10 10

145
(44)

6 8 8 10 10 6 8 10

202
(62)

291
(89)

347

(106)

372

(113)

145

(44)

291
(89)

347

(106)

TM-353 Page 11Syncrowave 250

3-11. Placing Jumper Links And Connecting Input Power

230 VOLTS 460 VOLTS200 VOLTS

LL LL LL

S-083 566-C

230 VOLTS

LL

220 VOLTS

LL

260 VOLTS

LL

460 VOLTS

LL

380 VOLTS

LL

380 VOLTS

LL

1

575 VOLTS

LL

S-010 587-B

415 VOLTS

LL

S-131 783-A

520 VOLTS

LL

S-047 672-A

Connect GND/PE
Conductor First

Check input voltage available at
site.

1 Jumper Link Label

Check label inside your unit–
only one label is on unit.

Y Only make connections for

the voltages shown on the la­bel inside your unit. Do not
make connections for any
other voltages. If jumper link
label is missing from inside

2

unit, check rating label (see
Section 3 - 4 ) f o r a l lowable i n­put voltages.

2 Jumper Links
Move jumper links to match input

voltage.
3 Input And Grounding

Conductors

Select size and length using
Section 3-10.

4 Line Disconnect Device
Select type and size of overcurrent

protection using Section 3-10.
Reinstall side panel.

Y Special installation may be

required where gasoline or
volatile liquids are present –
see NEC Article 511 or CEC
Section 2 0 .

Tools Needed:

GND/PE
Earth Ground

4

L1 (U)
L2 (V)

3

Connect GND/PE
Conductor First

3/8 in

3/8, 1/2, 7/16 in

ST-117 263-K

TM-353 Page 12 Syncrowave 250

4-1. Controls

6

5

4
3

2

SECTION 4 – OPERATION

1 Ammeter

87

9

10

11

12

13

14

1

See Section 4-3.
2 Voltmeter
See Section 4-3.
3 High Frequency Switch
See Section 4-11.
4 Output (Contactor) Switch
See Section 4-8.
5 Spot Time Switch And Control

(Optional)
See Section 4-5.
6 Preflow Time Control (Optional)
See Section 4-12.
7 AC Balance Control
See Section 4-6.
8 Crater Time Control And Switch
See Section 4-4.
9 Amperage Adjustment Control And

Switch
See Section 4-7.
10 Arc Force (Dig) Switch And Control
See Section 4-9.
11 Postflow Time Control
See Section 4-10.
12 High Temperature Shutdown Light

(CE Models Only)
Lights when unit overheats and shuts

down (see Section 3-3).
13 Power Switch And Pilot Light
Use switch to turn unit and light On and

Off.
14 Output Selector Switch
See Section 4-2.
15 High Frequency Control
See Section 4-11.

15

Ref. ST-117 264-F / Ref. ST-154 795-C

TM-353 Page 13Syncrowave 250

4-2. Output Selector Switch

1 Output Selector Switch

Y Do not use AC output in

damp areas, if movement is
confined, or if there is dan-

1

ger of falling. Use AC output
ONLY if required for the
welding process, and then
use a remote control.

Y Do not change position of

switch while welding or
while under load.

Use switch to select (DCEN) Direct
Current Electrode Negative, AC, or
(DCEP) Direct Current Electrode
Positive output without changing
weld output cable connections.

4-3. Meters

1 2

Ref. ST-181 675-A

1 Voltmeter
Voltmeter displays voltage at the

weld output terminals, but not nec­essarily the welding arc due to
cable resistance, poor connec­tions, etc.

2 Ammeter
Ammeter displays weld amperage

output o f unit.

TM-353 Page 14 Syncrowave 250

4-4. Crater Time Controls

1 Crater Time Control
Use control to reduce current over a

set period of time (0–15 seconds) at

1

2

the end of the weld cycle when NOT
using a remote current control.

2 Crater Time Switch
ON – provides crater time.
OFF – provides no crater time.
Place switch in the OFF position for

Shielded Metal Arc Welding
(SMAW).

Application:

Crater Time should be used while
GTAW welding materials that are
crack sensitive, and/or the operator
wants to eliminate the crater at the
end of the weld.

Note: This applies if the operator is
using an on/off only type control to
start and stop the welding process.

4-5. Spot Time Controls

1 Spot Time Switch
Place switch in the ON position to

turn on spot weld circuitry.

2

1

The (GTAW) TIG Spot process is
generally used with a direct current
electrode negative (DCEN) set-up.

Place switch in the OFF position to
turn off spot weld circuitry. Put
switch in the OFF position while do­ing Shielded Metal Arc Welding
(SMAW).

2 Spot T ime Control
Use control to set time (0–5.7 sec-

onds) for Gas Tungsten Arc
(GTAW) spot welds. Spot time be­gins at arc initiation. If the arc is bro­ken during the spot time cycle, the
timer stops but does not reset.
When the spot time has ended,
weld output stops. Postflow starts
when the remote contactor is
opened. The spot timer resets after
the contactor opens.

Application:

TIG spot welding is used for joining
thinner materials that are in close
contact, with the fusion method. A
good example would be joining coil
ends.

TM-353 Page 15Syncrowave 250

4-6. AC Balance Control

Balanced

3

More Penetration

10

More Cleaning

0

50% Electrode

Positive

50% Electrode

Negative

32% Electrode

Positive

68% Electrode

Negative

55% Electrode

Positive

45% Electrode

Negative

1 AC Balance Control

Balance Control (AC GTAW):

Control changes the AC output
square wave. Rotating the control
towards 10 provides deeper pene-

1

Output Waveforms ArcSetting

tration. Rotating the control towards
0 provides more cleaning action of
the workpiece.

When the control is in the Balanced
position, the wave shape provides
equal penetration and cleaning
action.

Application:

When welding on oxide forming ma­terials such as aluminum or magne­sium, excess cleaning is not neces­sary. To produce a good weld, only
a minimal amount, approximately a

0.10 in (2.5mm) of etched zone
along the weld toes is required.

Set control to 7 and adjust as nec­essary. Joint configuration, set-up,
process variables, and oxide thick­ness may affect setting.

Arc rectification can occur when
welding above 200 amps and/or
while welding with helium gas. If this
condition occurs, increasing the
Balance control towards maximum
penetration, may help to restabilize
the arc.

Ref. S-0795-A

TM-353 Page 16 Syncrowave 250

4-7. Amperage Adjustment Controls

2

1 Amperage Adjustment Control
Use control to adjust amperage,

1

and preset amperage on ammeter
(see Sect i o n 4 - 3 ) . T h i s c o n t r o l m a y
be adjusted while welding.

For remote amperage control,
front panel control setting is the
maximum amperage available. For
example: I f front panel control is set
to 200 A, the range of the remote
amperage control is 5 to 200 A.

For spot welding, use Amperage
Adjust control to select from 5–310
amps of peak amperage (see Sec­tion 4-5).

2 Amperage Control Switch
Use switch to select way of control-

ling amperage adjustment.
For front panel control, place switch

in the PANEL position.
For remote control, place switch in

REMOTE 14 position, and connect
remote control device (see Section
3-8).

4-8. Output (Contactor) Control Switch

Y Weld output terminals are

energized when Output
(Contactor) switch is On and
Power is On.

1

1 Output/Contactor Switch
Use switch to select way of control-

ling unit output.
For front panel control, place switch

in ON position.
When On is selected, HF and gas

control are disabled.
For remote control, place switch in

REMOTE 14 position, and connect
remote control device (see Section
3-8).

TM-353 Page 17Syncrowave 250

4-9. Arc Controls

1 Arc Control (Dig)

For AC And DC SMAW Welding

When set at 0, short-circuit amper­age at low arc voltage is the same

1

2

as normal welding amperage.
When setting is increased, short-

circuit amperage at low arc voltage
increases.

Set at 0 for GTA W welding.
2 Arc Control Switch
Place switch in the ON position to

turn on arc control circuitry. When
switch is i n the OFF position, no ad­ditional amperage is available at
low arc voltages. Place switch in
the OFF position while performing
Gas Tungsten Arc Welding
(GTAW).

Application:

Control helps arc starting or making
vertical or overhead welds by in­creasing amperage at low arc volt­age, and reduces electrode sticking
while welding.

4-10. Postflow Time Control

1 Postflow Time Control
Use control to set length of time

(0–70 seconds) gas flows after
welding stops. It is important to s e t
enough time to allow gas to flow un-

1

til after the tungsten and weld
puddle has cooled down.

Application:

Postflow is required to cool tung­sten and weld, and to prevent con­tamination of tungsten and weld. In­crease postflow time if tungsten or
weld are dark in appearance.

TM-353 Page 18 Syncrowave 250

4-11. High Frequency Controls

1

2

Y Place High Frequency

switch in Off position before
using the shielded metal arc
welding (SMAW) process.

1 High Frequency Switch
START – (Up position) provides H F

for arc starting only. High frequency
turns on to help start arc when out­put is enabled. High frequency
turns off when arc is started, and
turns on whenever arc is broken to
help restart arc.

Application:

HF Start is used when the DCEN
GTA W process is required.

OFF – provides no HF. Use OFF for
SMAW (stick electrode) welding.

CONTINUOUS – (Down position)
provides HF continuously through­out the weld.

Application:

HF Continuous is used when the
AC GTAW process is required.

2 High Frequency Intensity

Control

Use control to change amount of
HF energy used to start and main­tain the arc. Set as low as practical
to prevent interfering with electronic
equipment.

4-12. Preflow Time Control (Optional)

1 Preflow Time Control
Use control to set the length of time

(0–15 seconds) that gas flows be­fore an arc is started.

Application:

Preflow is used to purge the imme­diate weld area of atmosphere. Pre­flow also aids in consistent arc
starting.

1

TM-353 Page 19Syncrowave 250

SECTION 5 – THEORY OF OPERATION

1 Input Terminal Board TE1
Provides means for operation on

different input voltages.
2 Power Switch S1
Provide on/off control of unit.
3 Fan Motor FM
Provides cooling of internal compo-

nents.
4 Main T ransformer T1
Supplies power to weld output cir-

cuit, various control circuits, main
control board PC1, and fan motor
FM.

5 Control Board PC1
Controls weld output by changing

the SCR gate pulses (conduction
times) after comparing current
feedback to selected amperage
signal.

Also provides input connections for
switches S3, S5, S6, and S7.

6 Arc Control Switch S6 And

Control R2

R2 selects short-circuit amperage
when S6 i s O n , and High Frequen­cy control R13 is Off.

7 Crater Time Switch S7 And

Control R11

R11 selects crater time when S7 is
on, and Amperage Control switch
S5 is in Panel position.

8 Thermostat TP1
If T1 overheats, TP1 opens stop-

ping all weld output.
9 Output (Contactor) Switch S3
Selects On or remote contactor

control.
10 AC Balance Control R3
Controls changes to ac output

square wave.
11 Ammeter A1 And Voltmeter

V1

Display weld amperage and volt­age while welding.

12 Amperage Control Switch S5

And Adjustment Control R1

R1 selects weld output amperage
when S5 is in Panel.

13 Remote 14 Filter Board

PC2/Remote 14 Receptacle
RC1

PC2 protects unit from high fre­quency, and RC1 connects remote
amperage and contactor controls to
power source.

14 Circuit Breaker CB1
Protects 115 volts ac duplex recep-

tacle RC2 from overload.

1-Phase

Line

Input

Power

6

7

9

12

124

Input

Terminal

Board TE1

Arc Control

R2

Crater Time

Control

R11

Output

(Contactor)

Switch S3

Amperage

Adjustment

Control R1

6

7

8

10

AC Balance

11

12

Power
Switch

S1

31423

Fan

Motor

FM

Arc Control

Switch

S6

Crater Time

Switch

S7

Thermostat

TP1

Control

R3

♦

Ammeter

A1

Amperage

Control

Switch S5

1

5

φ1φ

15

1φ
Synchronization

Signal

Control

Board

PC1

Main

Transformer

Breaker

115 VAC Duplex

Receptacle

, 10 VAC

T1

115 VAC

Circuit

CB1

RC2

13

Remote 14

Filter Board

13

Amperage

115 VAC

PC2

Remote

Control

AC

Rectifier

SCR
Gating
Signals

16

17

24

Background

Main

SR1

Postflow

Timer

TD1

Gas

Valve

GS1

Power

Source

DC

TM-353 Page 20 Syncrowave 250

25

Stabilizer

Z1

Current Feedback

♦

26

Hall Device

HD1

27

Line

Filter

FL1

Voltage Feedback
Voltage Feedback

AC Or DC Control

1φ Power

Weld Current Circuit
External Circuits

Optional

28

Output

Selector

Switch

S4

♦

18

Preflow

♦

18

Preflow Time

Control

Switch

29

Integrated

Rectifier

SR2

Timer

TD3

R12

S9

♦

11

Voltmeter

V1

21

High

Frequency

Coupling

Coil T3

22

High

Frequency

Intensity

Control R13

21

Spark Gaps G

Capacitor

C4

20

High

Frequency

Transformer

T2

♦

19

Spot
Timer

TD2

♦

19

Spot Time

Control

R10

19♦

Spot Time

Switch

S8

115 VAC

30

Work Weld

Output

Terminal

30

Electrode

Weld Output

Terminal

15 115 Volts AC Duplex Recep-

tacle RC2

Provides connection point for auxil­iary equipment.

16 Postflow Timer TD1
Controls shielding gas and coolant

postflow time.
17 Gas Valve GS1
Provides shielding gas during the

weld cycle.
18 Preflow Timer TD3, Control

R12, And Switch S9

R12 selects time shielding gas
flows before arc starts. S9 is an in­tegral part of R12 so that when R12
is turned past zero (0), TD3 is off.

19 Spot Timer TD2, Switch S8,

And Control R10

R10 selects time output is available
when spot welding. S8 selects Off
or spot welding with remote contac­tor control.

20 High Frequency Transformer

T2

Steps up input voltage and charges
capacitor C4 .

21 Spark Gaps G And High Fre-

quency Coupling Coil T3

G provides path for C4 to discharge
into T3. T3 supplies high-frequency
to welding circuit.

22 High Frequency Intensity

Control R13

Changes amount of HF energy
used to sta r t and maintain the arc.

23 Main Rectifier SR1
Changes the ac output from T1 to

full-wave rectified dc.
24 Background Power Source
Provides reduced weld output rip-

ple at low weld output levels.
25 Stabilizer Z1
Smooths dc welding current.
26 Hall Device HD1
Provides current feedback signal to

PC1 through line filter FL1.
27 Line Filter FL1
Filters current feedback signal.
28 Output Selector Switch S4
Provides either AC or DC and out-

put polarity.
29 Integrated Rectifier SR2
Provides dc voltage feedback to

PC1.
30 Electrode And Work W eld

Output Terminals

Provide weld output.

TM-353 Page 21Syncrowave 250

SECTION 6 – TROUBLESHOOTING

6-1. Troubleshooting Table

. See Section 6-2 for test points and values and

Section 10 for parts location.

. Use MILLER Testing Booklet (Part No. 150 853)

when servicing this unit.

Trouble Remedy

Prior to Serial No. KG164875, no weld
output; unit completely inoperative –
Effective with Serial No. KG164875,
no weld output; unit completely inop­erative; PL2 off.

Replace building line fuse(s) or reset circuit breaker(s) if open.
Check for proper electrical input connections (see Section 3-11).
Check for proper jumper link position (see Section 3-11).
Check Power switch S1 and replace if necessary.
Prior to Serial No. KG164875, no weld

output; fan runs – Effective with Serial
No. KG164875, no weld output; fan
runs; PL2 on.

Check, repair or replace remote control device.
Allow a cooling period of approximately 15 minutes. If thermostats TP1 remain open, check continuity

Check circuit breaker CB1, and reset if open (see Section 7-2).
Place Output Selector switch S4 in desired position (see Section 4-2).
Check optional preflow timer board TD3, and replace if necessary.
Check optional spot timer relay TD2 for proper connections and resistance. Replace TD2 if

Check continuity of Spot Time switch S8. Check condition of contacts. Repair or replace S8 if neces-

Check SR1, and replace necessary components. If components are replaced, check capacitors C7

Unit provides only minimum weld
output.

Check control board PC1 and connections, and replace if necessary.

Unit provides only maximum weld
output.

Check connections for continuity to shunt device on units with Serial No. prior to KB110695.

TM-353 Page 22 Syncrowave 250

Be sure line disconnect switch is in the On position.

If using remote control, place Output (Contactor) switch S3 in Remote 14 position, and connect re­mote control to Remote 14 receptacle RC1 (see Sections 3-8 and Section 4-8). If remote is not being
used, place Output switch S3 in On position.

and replace if necessary (see Section 3-3).

necessary.

sary.

thru C10. Replace capacitor(s) if necessary.
Check control board PC1 and connections, and replace if necessary.
Effective with Serial No. KB1 10695, check resistance and connections of HD1; HD1 is 1600 ohms

±10% between pins 1 and 3 of plug PLG3. Check input and output voltages. Replace HD1 if
necessary.

Check position of Amperage Control switch S5 (see Section 4-7).

Increase Amperage Adjustment control R1 setting if a remote control is used (see Section 4-7).
Check, repair or replace remote control device.

Check resistance and connections of Amperage Adjustment control R1; R1 is 1000 ohms ±10%.
Replace R1 if necessary.

Check SCRs in main rectifier SR1, and replace if necessary. If any SCRs are replaced, Check capac­itors C7 through C10 for a short or open, and check for proper connections. Replace C7 through C10
if necessary.

Effective with Serial No. KB1 10695, check resistance and connections of HD1; HD1 is 1600 ohms
±10% between pins 1 and 3 of plug PLG3. Check input and output voltages. Replace HD1 if
necessary.

Check Amperage Adjustment control R1 for proper connections and resistance; R1 is 1000 ohms
±10%. Replace R1 if necessary.

Effective with Serial No. KB1 10695, check resistance and connections of HD1; HD1 is 1600 ohms
±10% between pins 1 and 3 of plug PLG3. Check input and output voltages. Replace HD1 if
necessary.

Check bypass capacitors C13, C14, C16, C17, C18, and C19 for broken leads, shorts, and leakage.
Replace if necessary.