xmt350cccvauto line (le073174)

8/18/2019 Xmt350cccvauto Line (Le073174)

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TM-2247P 2014−06

Eff w/Serial Number LE073174

XMT 350 CC/CV

Auto-Line

Arc Welding Power Source

Processes

Description

Multiprocess Welding

Visit our website at

www.MillerWelds.com

File: MULTIPROCESS


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INFORMATION ON OLDER UNITS

This manual includes operating information for current units. To obtain specific operating information for older models, download the applicable Owner’s Manual from www.MillerWelds.com

Effective with LK190017A, a FCAW position was added to the arc control.

Effective with LK190017A, when STICK mode is selected the amperage output can be controlled through the remote 14 receptacle. The unit will automatically sense if a remote control is connected. Prior units could only be controlled by the front panel V/A adjust knob.

Effective with LK450041A, optional low open circuit voltage operation was added to the Scratch Start Tig mode.

Effective with ME100269U, IGBT Module Kit 217625 was discontinued. See the parts list and Service Memo 1233 for additional information.

Effective with ME224001U, 115 volts AC was removed from remote 14 receptacle RC50.


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TABLE OF CONTENTS

SECTION 1 − SAFETY PRECAUTIONS FOR SERVICING 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-1. Symbol Usage 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-2. Servicing Hazards 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-3. California Proposition 65 Warnings 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-4. EMF Information 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 2 − DEFINITIONS 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-1. Additional Safety Symbols And Definitions 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-2. Miscellaneous Symbols And Definitions 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 3 − SPECIFICATIONS 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-1. Serial Number And Rating Label Location 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-2. Unit Specifications 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-3. Duty Cycle And Overheating 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-4. Volt-Ampere Curves 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 4 − INSTALLATION 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-1. Selecting a Location 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-2. Weld Output Receptacles And Selecting Cable Sizes* 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3. Remote 14 Receptacle Information 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-4. Optional 115 Volts AC Duplex Receptacle And Supplementary Protectors 10. . . . . . . . . . . . . . . . . . . . .

4-5. Optional Gas Valve Operation And Shielding Gas Connection 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-6. Electrical Service Guide 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-7. Connecting 1-Phase Input Power 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-8. Connecting 3-Phase Input Power 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 5 − OPERATION 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-1. Front Panel Controls 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-2. Mode Switch Settings 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 6 − GTAW OPERATION 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-1. Typical Connection For GTAW Process 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-2. Scratch Start TIG Welding Mode - GTAW Process 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-3. Lift-Arc TIG Welding Mode - GTAW Process 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-4. TIG Welding Mode - GTAW Process 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 7 − GMAW/FCAW OPERATION 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-1. Typical Connection For Remote Control Feeder GMAW/FCAW Process 24. . . . . . . . . . . . . . . . . . . . . . .

7-2. MIG Welding Mode - GMAW/FCAW Process 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-3. Typical Connection For Remote Control Feeder GMAW-P Process 26. . . . . . . . . . . . . . . . . . . . . . . . . . .

7-4. Pulsed MIG Welding Mode - GMAW-P Process 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-5. Typical Connection For Voltage-Sensing Feeder GMAW/FCAW Process 28. . . . . . . . . . . . . . . . . . . . . .

7-6. V-Sense Feeder Welding Mode - GMAW/FCAW Process 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 8 − SMAW/CAC-A OPERATION 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-1. Typical Connection For SMAW And CAC-A Process 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-2. CC Welding Mode - SMAW/CAC-A Process 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-3. Stick Welding Mode - SMAW/CAC-A Process 32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-4. Optional Low Open Circuit Voltage (OCV) Welding Modes 33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-5. Alternate Configuration Functions 33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 9 − THEORY OF OPERATION 34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9-1. Basic Training Circuit 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


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SECTION 10 − TROUBLESHOOTING 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-1. Checking Unit Before Applying Power 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-2. Measuring Input Capacitor Voltage 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-3. Input Pre-Regulator Module (MOD1) 42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-4. Input Pre-Regulator Module (MOD1) Test Point Values 42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-5. Inverter Module (MOD2) 43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-6. Inverter Module (MOD2) Test Point Values 43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-7. Power Interconnect Board PC2 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-8. Power Interconnect Board PC2 Test Point Values 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-9. Control Board PC1 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-10. Control Board PC1 − Test Point Values 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-11. Power Switch (S1) 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-12. Output Diodes D1, D2 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-13. Output Diodes D1, D2 Test Point Values 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-14. Stick Boost Rectifier (SR1) 48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-15. Stick Boost Rectifier (SR1) Test Point Values 48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-16. Troubleshooting Table 49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-17. Voltmeter/Ammeter Diagnostics 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-18. Troubleshooting Circuit Diagram (Use With Section 10-19) 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-19. Readings For Troubleshooting Circuit Diagram (Use With Section 10-18) 54. . . . . . . . . . . . . . . . . . .

10-20. Control Board PC1 Testing Information (Use with Section 10-21) 56. . . . . . . . . . . . . . . . . . . . . . . . . .

10-21. Control Board PC1 Test Point Values 57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-22. Control Board PC1 - Power Off Checks (Prior To LK450041A) 60. . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-23. Control Board PC1 − Power Off Checks (Prior To LK450041A) 61. . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-24. Control Board PC1 - Power Off Checks (Effective With LK450041A) 62. . . . . . . . . . . . . . . . . . . . . . .

10-25. Control Board PC1 − Power Off Checks (Effective With LK450041A) 63. . . . . . . . . . . . . . . . . . . . . . .

10-26. Power Interconnect Board PC2 Testing Information (Use with Section 10-27) 64. . . . . . . . . . . . . . . .

10-27. Power Interconnect Board PC2 Test Point Values 65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-28. Power Interconnect Board (PC2) - Power Off Checks (Prior To MB510232A) 68. . . . . . . . . . . . . . . .10-29. Power Interconnect Board (PC2) - Power Off Checks (Prior To MB510232A) 69. . . . . . . . . . . . . . . .

10-30. Power Interconnect Board (PC2) - Power Off Checks (Effective With MB510232A) 70. . . . . . . . . . .

10-31. Power Interconnect Board (PC2) - Power Off Checks (Effective With MB510232A) 71. . . . . . . . . . .

10-32. Front Panel/Display Board PC3 Testing Information 72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-33. Front Panel/Display Board PC3 Test Point Values 73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-34. Checking Unit Output After Servicing 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-35. Enabling Low Open Circuit Welding Modes (Optional) 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 11 − MAINTENANCE 76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11-1. Routine Maintenance 76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11-2. Blowing Out Inside Of Unit 76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11-3. Removing Fan Motor 77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 12 − ELECTRICAL DIAGRAMS 79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 13−

PARTS LIST FOR LE073174 THRU MC450892U 128. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SECTION 14 − PARTS LIST FOR MC450893U THRU ME120120U 134. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 15 − PARTS LIST FOR ME120121U AND FOLLOWING 140. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


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TM-2247 Page 1XMT 350 Auto Line

SECTION 1 − SAFETY PRECAUTIONS FOR SERVICINGProtect yourself and others from injury — read, follow, and save these important safety precautions and operating instructions.

1-1. Symbol UsageOM-2247AC 2014−05, safety_stm 2013-09

DANGER! − Indicates a hazardous situation which, ifnot avoided, will result in death or serious injury. Thepossible hazards are shown in the adjoining symbols

or explained in the text.Indicates a hazardous situation which, if not avoided,could result in death or serious injury. The possiblehazards are shown in the adjoining symbols or ex-plained in the text.

NOTICE − Indicates statements not related to personal injury.

Indicates special instructions.

This group of symbols means Warning! Watch Out! ELECTRICSHOCK, MOVING PARTS, and HOT PARTS hazards. Consult sym-bols and related instructions below for necessary actions to avoid thehazards.

1-2. Servicing Hazards

The symbols shown below are used throughout this manualto call attention to and identify possible hazards. When yousee the symbol, watch out, and follow the related instructionsto avoid the hazard.

Only qualified persons should test, maintain, and repair this

unit.

During servicing, keep everybody, especially children, away.

Do not touch live electrical parts.

Turn Off welding power source and wire feederand disconnect and lockout input power using

line disconnect switch, circuit breakers, or by removing plug from re-ceptacle, or stop engine before servicing unless the procedure spe-cifically requires an energized unit.

ELECTRIC SHOCK can kill.

Insulate yourself from ground by standing or working on dry insulat-ing mats big enough to prevent contact with the ground.

Do not leave live unit unattended.

If this procedure requires an energized unit, have only personnelfamiliar with and following standard safety practices do the job.

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

Disconnect input power conductors from deenergized supply lineBEFORE moving a welding power source.

SIGNIFICANT DC VOLTAGE exists in inverter weld-ing power sources AFTER removal of input power.

Turn Off inverter, disconnect input power, and discharge inputcapacitors according to instructions in Troubleshooting Section be-fore touching any parts.

STATIC (ESD) can damage PC boards.

Put on grounded wrist strap BEFORE handlingboards or parts.

Use proper static-proof bags and boxes tostore, move, or ship PC boards.

FIRE OR EXPLOSION hazard.

Do not place unit on, over, or near combustiblesurfaces.

Do not service unit near flammables.

FLYING METAL or DIRT can injure eyes.

Wear safety glasses with side shields or faceshield during servicing.

Be careful not to short metal tools, parts, or

wires together during testing and servicing.

HOT PARTS can burn.

Do not touch hot parts bare handed.

Allow cooling period before working onequipment.

To handle hot parts, use proper tools and/orwear heavy, insulated welding gloves andclothing to prevent burns.

EXPLODING PARTS can injure.

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

Always wear a face shield and long sleeveswhen servicing inverters.

SHOCK HAZARD from testing.

Turn Off welding power source and wire feederor stop engine before making or changing me-ter lead connections.

Use at least one meter lead that has a self-retaining spring clip such as an alligator clip.

Read instructions for test equipment.

FALLING EQUIPMENT can injure.

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

Use equipment of adequate capacity to lift andsupport unit.

If using lift forks to move unit, be sure forks are long enough toextend beyond opposite side of unit.

Follow the guidelines in the Applications Manual for the RevisedNIOSH Lifting Equation (Publication No. 94−110) when manu-ally lifting heavy parts or equipment.


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TM-2247 Page 2 XMT 350 Auto Line

MOVING PARTS can injure.

Keep away from moving parts such as fans.

Keep away from pinch points such as driverolls.

Have only qualified persons remove doors,panels, covers, or guards for maintenance andtroubleshooting as necessary.

Keep hands, hair, loose clothing, and toolsaway from moving parts.

Reinstall doors, panels, covers, or guardswhen maintenance is finished and before re-connecting input power.

ELECTRIC AND MAGNETIC FIELDS (EMF)can affect Implanted Medical Devices.

Wearers of Pacemakers and other ImplantedMedical Devices should keep away from serv-icing areas until consulting their doctor and thedevice manufacturer.

OVERUSE can cause OVERHEATING.

Allow cooling period; follow rated duty cycle. Reduce current or reduce duty cycle before

starting to weld again.

Do not block or filter airflow to unit.

H.F. RADIATION can cause interference.

High-frequency (H.F.) can interfere with radionavigation, safety services, computers, andcommunications equipment.

Have only qualified persons familiar withelectronic equipment install, test, and serviceH.F. producing units.

The user is responsible for having a qualified electrician prompt-ly correct any interference problem resulting from the installa-tion.

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

Have the installation regularly checked and maintained.

Keep high-frequency source doors and panels tightly shut, keepspark gaps at correct setting, and use grounding and shielding tominimize the possibility of interference.

READ INSTRUCTIONS.

Use Testing Booklet (Part No. 150 853) whenservicing this unit.

Consult the Owner’s Manual for welding safetyprecautions.

Use only genuine replacement parts from the manufacturer.

Read and follow all labels and the Technical Manual carefully be-

fore installing, operating, or servicing unit. Read the safety in-formation at the beginning of the manual and in each section.

Perform maintenance and service according to the TechnicalManual, industry standards, and national, state, and local codes.

1-3. California Proposition 65 Warnings

Welding or cutting equipment produces fumes or gaseswhich contain chemicals known to the State of California tocause birth defects and, in some cases, cancer. (CaliforniaHealth & Safety Code Section 25249.5 et seq.)

This product contains chemicals, including lead, known tothe state of California to cause cancer, birth defects, or otherreproductive harm. Wash hands after use.

1-4. EMF Information

Electric current flowing through any conductor causes localized electricand magnetic fields (EMF). The current from arc welding (and allied pro-cesses including spot welding, gouging, plasma arc cutting, andinduction heating operations) creates an EMF field around the weldingcircuit. EMF fields may interfere with some medical implants, e.g. pace-makers. Protective measures for persons wearing medical implantshave to be taken. For example, restrict access for passers−by or con-duct individual risk assessment for welders. All welders should use thefollowing procedures in order to minimize exposure to EMF fields fromthe welding circuit:

1. Keep cables close together by twisting or taping them, or using acable cover.

2. Do not place your body between welding cables. Arrange cablesto one side and away from the operator.

3. Do not coil or drape cables around your body.

4. Keep head and trunk as far away from the equipment in thewelding circuit as possible.

5. Connect work clamp to workpiece as close to the weld aspossible.

6. Do not work next to, sit or lean on the welding power source.

7. Do not weld whilst carrying the welding power source or wirefeeder.

About Implanted Medical Devices:

Implanted Medical Device wearers should consult their doctor and thedevice manufacturer before performing or going near arc welding, spot

welding, gouging, plasma arc cutting, or induction heating operations.If cleared by your doctor, then following the above procedures is recom-mended.


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SECTION 2 − DEFINITIONS

2-1. Additional Safety Symbols And Definitions

Some symbols are found only on CE products.

Warning! Watch Out! There are possible hazards as shown by the symbols.

Safe1 2012−05

Do not discard product (where applicable) with general waste.Reuse or recycle Waste Electrical and Electronic Equipment (WEEE) by disposing at a designated collectionfacility.Contact your local recycling office or your local distributor for further information.

Safe37 2012−05

Wear dry insulating gloves. Do not touch electrode with bare hand. Do not wear wet or damaged gloves.

Safe2 2012−05

Protect yourself from electric shock by insulating yourself from work and ground.

Safe3 2012−05

Disconnect input plug or power before working on machine.

Safe5 2012−05

Keep your head out of the fumes.

Safe6 2012−05

Use forced ventilation or local exhaust to remove the fumes.

Safe8 2012−05

Use ventilating fan to remove fumes.

Safe10 2012−05

Keep flammables away from welding. Do not weld near flammables.

Safe12 2012−05

Welding sparks can cause fires. Have a fire extinguisher nearby, and have a watchperson ready to use it.

Safe14 2012−05


8/150


Do not weld on drums or any closed containers.

Safe16 2012−05

Do not remove or paint over (cover) the label.

Safe20 2012−05

Disconnect input plug or power before working on machine.

Safe30 2012−05

Flying pieces of parts can cause injury. Always wear a face shield when servicing unit.

Safe27 2012−05

Always wear long sleeves and button your collar when servicing unit.

Safe28 2012−05

After taking proper precautions as shown, connect power to unit.

Safe29 2012−05

Do not use one handle to lift or support unit.

Safe31 2012−05

Wear hat and safety glasses. Use ear protection and button shirtcollar. Use welding helmet with correct shade of filter. Wear completebody protection.

Safe38 2012−05

Kasjf;laksf;lkasdf'l;aksdf;lkasd;flksadflkasd;lk



Become trained and read the instructions before working on themachine or welding.

Safe40 2012−05

>60sec

V

V

V

Hazardous voltage remains on input capacitors after power is turnedoff. Do not touch fully charged capacitors. Always wait 60 secondsafter power is turned off before working on unit, OR check input ca-pacitor voltage, and be sure it is near 0 before touching any parts.

Safe43 2012−05

=< 60 Always lift and support unit using both handles. Keep angle of liftingdevice less than 60 degrees.

Use a proper cart to move unit.

Safe44 2012−05


9/150


2-2. Miscellaneous Symbols And Definitions

A Amperage V Voltage On Off

Output Positive Negative Remote

Shielded Metal ArcWelding (SMAW)

Gas Tungsten ArcWelding

Gas Metal ArcWelding (GMAW)

Voltage Input

Lift-Arc Operation(GTAW) % Percent Foot Control Line Connection

Pulsed Increase Single Phase Three Phase

Notes


10/150


SECTION 3 − SPECIFICATIONS

3-1. Serial Number And Rating Label LocationThe serial number and rating information for this product is located on the rear. Use rating label to determine input power requirements and/or ratedoutput. For future reference, write serial number in space provided on back cover of this manual.

3-2. Unit Specifications

InputPower Rated Output

VoltageRange in CV Mode

AmperageRange inCC Mode

Max.Open-Circuit

Voltage

RMS Amps Input at Rated Load Output,60 Hz 3-Phase at NEMA Load Voltages

and Class I Rating

KVA KW208 V 230 V 400 V 460 V 575 V

3-Phase 350 A at 34VDC, 60%Duty Cycle

10−38 V 5−425 A 75 VDC 40.4 36.1 20.6 17.8 14.1 14.2 13.6

1-Phase 300 A at 32VDC, 60%

Duty Cycle*

60.8 54.6 29.7 25.4 19.9 11.7 11.2

*See Section 3-3 for Duty Cycle Rating.

6 Minutes Welding 4 Minutes Resting

3-3. Duty Cycle And Overheating

Duty Cycle is percentage of 10 minutes thatunit can weld at rated load without overheating.

If unit overheats, output stops, a Help mes-sage is displayed and cooling fan runs. Wait fif-teen minutes for unit to cool. Reduce amper-age or voltage, or duty cycle before welding.

Single Phase Operation: The unit is sup- plied with a 8 AWG power cord. The rated output with 8 AWG is 300 amps, 32 volts at 40% duty cycle. To achieve60% duty cycle change cord to 6 AWG.

NOTICE− Exceeding duty cycle can damageunit and void warranty.

60% Duty Cycle

Overheating0

15

A or V

ORReduce Duty CycleMinutes Ref. 216 568-A

% DUTY CYCLE

THREE PHASE

OPERATION

6AWG POWER CORD

8AWG POWER CORD

SINGLE PHASEOPERATION

W E L D I N G A M P E R E S

10 15 20 25 30 40 50 60 70 80 90 100

100

150

200

250

300

350

400425

500


11/150


3-4. Volt-Ampere Curves

217 836-A / 217 837-B

Volt-ampere curves show minimumand maximum voltage and amper-age output capabilities of weldingpower source. Curves of other set-tings fall between curves shown.

0

10

20

30

40

50

60

70

80

90

100

0 100 200 300 400 500

50%

75%100%

25%0%

AMPERAGE

V O L T S

A. CC Mode

GTAWMAX

SMAWMAX

SMAW80A

ARCCONTROL

GTAWMN

0

10

20

30

40

50

60

70

80

90

100

0 100 200 300 400 500

V O L T S

B. CV Mode

AMPERAGE

MAX

MIN

Notes


12/150


SECTION 4 − INSTALLATION

! Do not move or operate unitwhere it could tip.

4-1. Selecting a Location

loc_2 3/96 - Ref. ST-151 556 / Ref. 803 879-B

1 Lifting Handles

Use handles to lift unit.

2 Hand Cart

Use cart or similar device to moveunit.

3 Line Disconnect Device

Locate unit near correct inputpower supply.

! Special installation may berequired where gasoline orvolatile liquids are present −see NEC Article 511 or CEC

Section 20.

24 in.(610 mm)

17 in.(432 mm)

12-1/2 in.(318 mm)

Movement

1

2

Location3

Dimensions And Weight

18 in.(460 mm)

18 in.(460 mm)

80 lb (36.3 kg)

1


13/150


4-2. Weld Output Receptacles And Selecting Cable Sizes*

NOTICE− The Total Cable Length in Weld Circuit (see table below) is the combined length of both weld cables. For example, if the power source is100 ft (30 m) from the workpiece, the total cable length in the weld circuit is 200 ft (2 cables x 100 ft). Use the 200 ft (60 m) column to determine cable

size.

! Turn off power be-fore connecting toweld output termi-nals.

! Do not use worn,damaged, under-sized, or repairedcables.

Weld Output

Terminals

Weld Cable Size** and Total Cable (Copper) Length in Weld CircuitNot Exceeding***

100 ft (30 m) or Less150 ft(45 m)

200 ft(60 m)

250 ft(70 m)

300 ft(90 m)

350 ft(105 m)

400 ft(120 m)

WeldingAmperes

10 − 60%DutyCycle

AWG (mm2 )

60 − 100%DutyCycle

AWG (mm2 )

10 − 100% Duty Cycle

AWG (mm2 )

+

−

Output Receptacles

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)2x2/0(2x70)

2x2/0(2x70)

300 1 (50) 1/0 (60) 2/0 (70) 3/0 (95) 4/0 (120)2x2/0(2x70)

2x3/0(2x95)

2x3/0(2x95)

350 1/0 (60) 2/0 (70) 3/0 (95) 4/0 (120)2x2/0(2x70)

2x3/0(2x95)

2x3/0(2x95)

2x4/0(2x120)

400 1/0 (60) 2/0 (70) 3/0 (95) 4/0 (120)2x2/0(2x70)

2x3/0(2x95)

2x4/0(2x120)

2x4/0(2x120)

500 2/0 (70) 3/0 (95) 4/0 (120)2x2/0(2x70)

2x3/0(2x95)

2x4/0(2x120)

3x3/0(3x95)

3x3/0(3x95)

600 3/0 (95) 4/0 (120)2x2/0(2x70)

2x3/0(2x95)

2x4/0(2x120)

3x3/0(3x95)

3x4/0(3x120)

3x4/0(3x120)

* This chart is a general guideline and may not suit all applications. If cable overheats, use next size larger cable.

**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.( ) = mm2 for metric use

***For distances longer than those shown in this guide, call a factory applications rep. at 920-735-4505 (Miller) or 1-800-332-3281 (Hobart).

Ref. S-0007-K 2013−10


14/150


4-3. Remote 14 Receptacle Information

A J

BK I

C L N H

D M G

E F

Socket* Socket Information

24 VOLTS AC A 24 volts AC. Protected by supplementary protect-

or CB2.

B Contact closure to A completes 24 volts ACcontactor control circuit.

REMOTEOUTPUT

CONTROL

C Output to remote control; 0 to +10 volts DC, +10volts DC in MIG mode.

D Remote control circuit common.

E 0 to +10 volts DC input command signal fromremote control.

M CC/CV select

A/V AMPERAGE VOLTAGE

F Current feedback; +1 volt DC per 100 amperes.

H Voltage feedback; +1 volt DC per 10 output recep-tacle volts.

GND

G Circuit common for 24 volts AC circuits.

K Chassis common.

*The remaining sockets are not used.

803 691-C

1 115 V 10 Amp AC Receptacle

2 Supplementary Protector CB1


CB1 protects duplex receptacle

from overload.CB2 protects 24 volts AC portionof Remote 14 receptacle fromoverload.

Press button to reset protector.

2 3

1

4-4. Optional 115 Volts AC Duplex Receptacle And Supplementary Protectors


15/150


4-5. Optional Gas Valve Operation And Shielding Gas Connection

Ref. 803 705-A / Ref. 803 691-C

Obtain gas cylinder and chain torunning gear, wall, or other station-ary support so cylinder cannot falland break off valve.

1 Cylinder

2 Regulator/Flowmeter

Install so face is vertical.

3 Gas Hose Connection

Fitting has 5/8-18 right-handthreads. Obtain and install gashose.

4 Gas In Fitting

5 Gas Out Fitting

The Gas In and Gas Out fittingshave 5/8-18 right-hand threads.Obtain proper size, type, and lengthhose and make connections as fol-lows:

Connect hose from shielding gassupply regulator/flowmeter to GasIn fitting.

Connect hose coupler to torch.Connect one end of gas hose tohose coupler. Connect remainingend of gas hose to Gas Out fitting.

Operation

The gas solenoid controls gas flowduring the TIG process as follows:

Remote TIG

Gas flow starts with remote contac-tor on.

Gas flow stops at end of post−flowif current was detected, or with re-mote contactor off if no current wasdetected.

Lift − Arc TIG

Gas flow starts when tungstentouches work (touch sensed).

Gas flow stops at end of post−flow.

Scratch Start TIG

Gas flow starts when current is de-tected.

Gas flow stops at end of post−flow.

Post−flow time is factory set to 5seconds per 100 amps of weld cur-rent. The minimum post−flow timeis 5 seconds. The maximum post−flow is 20 seconds (post flow set-tings are not adjustable by the enduser).

4

3

1

2

GAS IN

GAS OUT

5


16/150


4-6. Electrical Service Guide Elec Serv 2014−01

NOTICE− INCORRECT INPUT POWER can damage this welding power source. Phase to ground voltage shall not exceed +10% of rated inputvoltage.

NOTICE− Actual input voltage should not be 10% less than minimum and/or 10% more than maximum input voltages listed in table. If actual input voltage is outside this range, output may not be be available.

Failure to follow these electrical service guide recommendations could create an electric shock or fire hazard. These recommenda-tions are for a dedicated circuit sized for the rated output and duty cycle of the welding power source.

In dedicated circuit installations, the National Electrical Code (NEC) allows the receptacle or conductor rating to be less than the ratingof the circuit protection device. All components of the circuit must be physically compatible. See NEC articles 210.21, 630.11, and630.12.

Single-Phase

Input Voltage (V) 208 230 400 460 575

Input Amperes (A) At Rated Output 60.8 54.6 29.7 25.4 19.9

Max Recommended Standard Fuse Rating In Amperes 1

Time-Delay Fuses 2 70 60 35 30 25

Normal Operating Fuses 3 80 80 45 40 30

Min Input Conductor Size In AWG/Kcmil 4 8 8 10 12 12

Max Recommended Input Conductor Length In Feet (Meters)72

(22)89

(27)176(54)

140(43)

219(67)

Min Grounding Conductor Size In AWG/Kcmil 4 8 8 10 12 12

Three-Phase

Input Voltage (V) 208 230 400 460 575

Input Amperes (A) At Rated Output 40.4 36.1 20.6 17.8 14.1

Max Recommended Standard Fuse Rating In Amperes 1

Time-Delay Fuses 2 45 40 25 20 15

Normal Operating Fuses 3 60 50 30 25 20

Min Input Conductor Size In AWG/Kcmil 4 8 10 12 14 14

Max Recommended Input Conductor Length In Feet (Meters)119(36)

96(29)

175(53)

150(46)

234(71)

Min Grounding Conductor Size In AWG/Kcmil 4 10 10 12 14 14

Reference: 2014 National Electrical Code (NEC) (including article 630)

1 If a circuit breaker is used in place of a fuse, choose a circuit breaker with time-current curves comparable to the recommended fuse.

2 “Time-Delay” fuses are UL class “RK5”. See UL 248.3 “Normal Operating” (general purpose - no intentional delay) fuses are UL class “K5” (up to and including 60 amps), and UL class “H” ( 65 amps and

above).4 Conductor data in this section specifies conductor size (excluding flexible cord or cable) between the panelboard and the equipment per NEC Table

310.15(B)(16). If a f lexible cord or cable is used, minimum conductor size may increase. See NEC Table 400.5(A) for flexible cord and cablerequirements.


17/150


Notes


18/150


4-7. Connecting 1-Phase Input Power

Input1 2012−05 − Ref. 803 766-C

1

6

54

2

7

6

L1

L2

1

=GND/PE Earth Ground

3

3

1

8

9

10

Tools Needed:


19/150


4-7. Connecting 1-Phase Input Power (Continued)

Input1 2012−05

! Installation must meet all National andLocal Codes − have only qualified per-sons make this installation.

! Disconnect and lockout/tagout input

power before connecting input con-ductors from unit. Follow establishedprocedures regarding the installationand removal of lockout/tagout devices.

! Always connect green or green/yellowconductor to supply grounding termi-nal first, and never to a line terminal.

NOTICE − The Auto-Line circuitry in this unit automatically adapts the power source to the primary voltage being applied. Check input voltage available at site. This unit can be con-

nected to any input power between 208 and 575 VAC without removing cover to relink the power source.

See rating label on unit and check input volt-age available at site.

1 Black And White Input Conductor (L1 And L2)

2 Red Input Conductor

3 Green Or Green/Yellow GroundingConductor

4 Insulation Sleeving

5 Electrical Tape

Insulate and isolate red conductor as shown.

6 Input Power Cord.

7 Disconnect Device (switch shown in theOFF position)

8 Disconnect Device Grounding Terminal

9 Disconnect Device Line Terminals

Connect green or green/yellow grounding

conductor to disconnect device grounding ter-minal first.

Connect input conductors L1 and L2 to discon-nect device line terminals.

10 Over-Current Protection

Select type and size of over-current protectionusing Section 4-6 (fused disconnect switchshown).

Close and secure door on disconnect device.Follow established lockout/tagout proceduresto put unit in service.

Notes

Work like a Pro!

Pros weld and cut

safely. Read the

safety rules at

the beginning

of this manual.


20/150


4-8. Connecting 3-Phase Input Power

input2 2012−05 − Ref. 803 766-C

= GND/PE Earth Ground

L1

2

1

L2

L3

3

3

4

5

6

7

Tools Needed:


21/150


input2 2012−05

! Installation must meet all National andLocal Codes − have only qualified per-sons make this installation.

! Disconnect and lockout/tagout input

power before connecting input con-ductors from unit. Follow establishedprocedures regarding the installationand removal of lockout/tagoutdevices.

! Always connect green or green/yellowconductor to supply grounding termi-nal first, and never to a line terminal.

NOTICE− The Auto-Line circuitry in this unit automatically adapts the power source to the primary voltage being applied. Check input

voltage available at site. This unit can be connected to any input power between 208 and 575 VAC without removing cover to relink the power source.

See rating label on unit and check input volt-age available at site.

For Three-Phase Operation

1 Input Power Cord.

2 Disconnect Device (switch shown in theOFF position)

3 Green Or Green/Yellow GroundingConductor

4 Disconnect Device Grounding Terminal

5 Input Conductors (L1, L2 And L3)

6 Disconnect Device Line Terminals

Connect green or green/yellow groundingconductor to disconnect device grounding ter-

minal first.

Connect input conductors L1, L2, and L3 todisconnect device line terminals.

7 Over-Current Protection

Select type and size of over-current protec-tion using Section 4-6 (fused disconnectswitch shown).

Close and secure door on disconnect device.Follow established lockout/tagout proceduresto put unit in service.

4-8. Connecting 3-Phase Input Power (Continued)

Notes

Work like a Pro!

Pros weld and cut

safely. Read the

safety rules at

the beginning

of this manual.


22/150


SECTION 5 − OPERATION

5-1. Front Panel Controls

Ref. 803 692-B / Ref. 239 083-A

6

2 3 4

7 51

Weld process operation sections de- scribe functionality of the identified items(See Sections 6-2 thru 8-3 ).

The fan motor is thermostatically con-trolled and only runs when cooling is

needed.

1 Remote 14 Receptacle

For remote control, make connections to Re-mote 14 receptacle. In TIG and STICK modesthe remote control is a percent of V/A Adjustcontrol setting (value selected on V/A Adjustis maximum available on remote). In the MIGmode, remote control provides full range of unit output regardless of V/A Adjust controlsetting.

2 Left Display

3 Right Display

The meters display the actual weld output

values after arc initiation and remains displayed for approximately three seconds after the arc is broken.

4 Adjust Control

5 Arc Control

Control adjusts Dig when Stick or CC mode isselected on mode switch. When set towardsminimum, short-circuit amperage at low arcvoltage is the same as normal weldingamperage.

When set towards maximum, short-circuitamperage is increased at low arc voltage toassist with arc starts as well as reduce stick-ing while welding.

Select setting best suited for application.

Control adjusts inductance when MIG orV-Sense Feeder position is selected on themode switch. Inductance (0-100%) deter-mines the “wetness” of the weld puddle. When

set towards maximum, “wetness” (puddlefluidity) increases.

For self-shielding wires (FCAW) adjust arccontrol to FCAW setting.

When Pulsed MIG or one of the TIG modes isselected, this control is not functional.

6 Power Switch

7 Mode Switch

The Mode switch setting determines both theprocess and output On/Off control (see Sec-tion 5-2).

For Air Carbon Arc (CAC-A) cutting and goug-ing, place switch in Stick position. For best re-sults, place Arc Control in the maximum posi-tion.

8 Weld Output Terminal (−)

9 Optional Gas Valve Knockout

10 Weld Output Terminal (+)

10

9

8


23/150


5-2. Mode Switch Settings

Switch Position Process Output Control Panel Adjust Remote Adjust

Scratch Start TIG GTAW Electrode Hot Amps % Panel Amps

Lift-Arc TIG GTAW Electrode Hot Amps % Panel Amps

TIG GTAW Remote 14 Amps % Panel Amps

MIG GMAW Remote 14 Volts Volts

Pulsed MIG GMAW-P* Remote 14 N/A Arc Length (0−100)

CCSMAW

CAC-ARemote 14 Amps % Panel Amps

StickSMAW

CAC-AElectrode Hot Amps % Panel Amps**

V-Sense Feeder GMAW Electrode Hot Volts Volts

*Requires an external pulsing device.

**See Section 8-5 Alternate Configuration Functions

Notes


24/150


SECTION 6 − GTAW OPERATION

6-1. Typical Connection For GTAW Process

264 339-A

! Turn off power before making con-nections.

1 Foot Control

2 Positive (+) Weld Output Terminal


Connect desired remote control to Remote14 receptacle if required.

4 Gas In Connection (Optional)

5 Gas Cylinder

6 Gas Out Connection (Optional)

7 Negative (−) Weld Output Terminal

8 TIG Torch

9 Workpiece

3

7

4

2

6

1

8

5

9


25/150


6-2. Scratch Start TIG Welding Mode - GTAW Process

! Weld terminals are energized at alltimes in Scratch Start TIG weldingmode.

1 Mode Switch

2 Left Display

3 Right Display

4 Adjust Control

Setup

For typical system connections refer toSection 6-1.

Rotate Mode Switch to SCRATCH STARTTIG position as shown.

The open circuit voltage is shown in the LeftDisplay. Preset amperage is shown in theRight Display.

Operation

The Adjust Control is used to set desiredpreset amperage.

If a remote control is used for amperage adjustment, the adjustment will function as a percentage of the preset

amperage.

For best results, gently scratch thetungsten electrode to the work to initi-

ate an arc. To minimize arc flare at theend of the weld, pull back the electrodequickly to extinguish the arc.

239 083-A

2 3

1

4

8 4. 5 8 5


26/150


6-3. Lift-Arc TIG Welding Mode - GTAW Process

! Weld terminals are energized at alltimes in Lift Arc TIG welding mode.

1 Mode Switch

2 Left Display

3 Right Display

4 Adjust Control

5 Workpiece

6 Tungsten Electrode

Setup


Rotate Mode Switch to LIFT-ARC TIG posi-tion as shown.

The open-circuit voltage is shown in theLeft Display. Preset amperage is shown inthe Right Display.

Normal open-circuit voltage is not presentbefore the electrode touches the work-piece, instead a low sensing voltage ispresent. The sensing voltage allows theelectrode to touch the workpiece withoutoverheating, sticking, or getting contami-nated.

Operation


If a remote control is used for amperage adjustment, the adjustment will function as a percentage of the preset

amperage.

For best results, firmly touch the tungsten electrode to the workpiece at theweld start point. Hold electrode toworkpiece for 1-2 seconds, and lift electrode. An arc will form when theelectrode is lifted. To minimize arc flare

at the end of the weld, pull back theelectrode quickly to extinguish the arc.

239 083-A

1 − 2Seconds“Touch”

Do NOT Strike Like A Match!

65

2 3

1

4

1 3. 5 8 5


27/150


6-4. TIG Welding Mode - GTAW Process

! Weld terminals are energizedthrough the remote control in TIGwelding mode.

1 Mode Switch

2 Left Display

3 Right Display

4 Adjust Control

SetupFor typical system connections refer toSection 6-1.

Rotate Mode Switch to TIG position asshown.

The preset amperage is shown in the RightDisplay.

OperationThe Adjust Control is used to set desiredpreset amperage.

A remote control is required to turn on theweld output.

If the remote control has an amperage adjustment, the adjustment will func-tion as a percentage of the preset am-

perage.

For best results, gently scratch thetungsten electrode to the work to initi-

ate an arc. To minimize arc flare at theend of the weld, pull back the electrodequickly to extinguish the arc.

239 083-A

2 3

1

4

8 5


28/150


SECTION 7 − GMAW/FCAW OPERATION

7-1. Typical Connection For Remote Control Feeder GMAW/FCAW Process

264 343-A

! Turn off power before makingconnections.

1 Remote 14-Receptacle



4 Ground Cable to Workpiece

5 Workpiece

6 Gun

7 Wire Feeder

8 Gas Hose

9 Gas Cylinder

Use of shielding gas is dependant on WireType.

The connection diagram illustratesDCEP (reverse polarity) suitable for all wires except self-shielded FCAW. The

majority of self-shielded FCAW wires require DCEN (straight polarity).

3

4

5

6

7

8

9

1

2


29/150


7-2. MIG Welding Mode - GMAW/FCAW Process

! Weld terminals are energizedthrough the remote control in MIGwelding mode.

1 Mode Switch

2 Left Display

3 Right Display

4 Adjust Control

Setup


Rotate Mode Switch to MIG position asshown.

The preset voltage is shown in the Left Dis-play.

Operation

The Adjust Control is used to set desiredpreset voltage.

The preset voltage can be adjusted re- motely at the wire feeder if the feeder

has a voltage control. This voltage con-trol will override the Adjust Control of

preset voltage on the welding power source.

Arc Control (Inductance)

Rotate Arc Control to select desired induc-tance setting from 0 to 100. Use lower in-ductance settings to stiffen the arc and re-duce puddle fluidity. Use higher inductancesettings to soften the arc and increasepuddle fluidity.

239 083-A

2 3

1

4

25.0


30/150


7-3. Typical Connection For Remote Control Feeder GMAW-P Process

264 347-A

! Turn off power before makingconnections.

1 Optima - External Pulsing Device

2 Remote 14-Receptacle




6 Workpiece

7 Gun

8 Wire Feeder

9 Gas Hose

10 Gas Cylinder



majority of self-shielded FCAW wires require DCEN (straight polarity). Flux cored wires are not pulsed. No pulse

program available for FCAW.

4

5

6

7

8

9

10

3

2

1


31/150


7-4. Pulsed MIG Welding Mode - GMAW-P Process

! Weld terminals are energizedthrough the remote control inPulsed MIG welding mode.

1 Mode Switch

2 Left Display

3 Right Display

4 Adjust Control

Setup


Rotate Mode Switch to PULSED MIG posi-tion as shown.

Left and Right Display will show PPP PPP.

Operation

This unit requires an external pulsingdevice, like an Optima to pulse MIG weld.See Optima owner’s manual for more in-formation.

239 083-A

2 3

1

4

P P. P P PP


32/150


7-5. Typical Connection For Voltage-Sensing Feeder GMAW/FCAW Process

264 348-A





4 Workpiece

5 Voltage Sensing Clamp

6 Gun

7 Gun Trigger Receptacle

8 Wire Feeder

9 Gas Hose

10 Gas Cylinder



majority of self-shielded FCAW wires require DCEN (straight polarity).

2

3

9

10

8

7

5

6

4

1


33/150


7-6. V-Sense Feeder Welding Mode - GMAW/FCAW Process

! Weld terminals are energized at alltimes in V-Sense Feeder weldingmode.

1 Mode Switch

2 Left Display

3 Right Display

4 Adjust Control

Setup

For typical system setup connections refer

to Section 7-5.

Rotate Mode Switch to V-SENSE FEEDERposition as shown.

The Left Display toggles between open cir-cuit voltage and preset voltage.

Operation

The Adjust Control is used to set desiredpreset voltage.

The Left Display toggling momentarily pauses while the preset voltage is adjusted.

Arc Control (Inductance)

Rotate Arc Control to select desired induc-tance setting from 0 to 100. Use lower in-ductance settings to stiffen the arc and re-duce puddle fluidity. Use higher inductancesettings to soften the arc and increasepuddle fluidity.

239 083-A

2 3

1

4

25.0


34/150


SECTION 8 − SMAW/CAC-A OPERATION

6

34

21

8-1. Typical Connection For SMAW And CAC-A Process

264 349-A


1 Electrode Holder(Carbon Arc)

For CAC-A process connect carbon arc

cutting torch to to positive weld output ter-minal.

2 Electrode Holder



Connect desired remote control to remote14 receptacle as required.

5 Compressed Air LIne


7 Workpiece

5

7


35/150


8-2. CC Welding Mode - SMAW/CAC-A Process

! Weld terminals are energizedthrough the remote control in CCwelding mode.

1 Mode Switch

2 Right Display

3 Adjust Control

Setup


Rotate Mode Switch to CC position asshown.

The preset amperage is shown in the RightDisplay with the Amps Indicator lit.

Operation


A remote control is required to turn on theweld output.

If the remote control has an amperage adjustment, the adjustment will func-tion as a percentage of the preset am-

perage. When Configuration 3 is selected remote control preset will be displayed in the amperage window. See section 8-5 for more information regarding Alternate Configuration Func-tionality.

Adaptive Hot Start automatically increaseswelding amperage at the start of a weld.This helps eliminate electrode sticking dur-ing arc initiation.

For best results at the end of the weld, pull back the electrode quickly to extinguish the arc.

Arc Control (Dig)

Rotate Arc Control to select desired dig set-ting from 0 to 100.

Dig control allows the arc characteristics,soft versus stiff, to be changed for specificapplications and electrodes. Lower the dig

setting for smooth running electrodes likeE7018 and increase the dig setting for stiff-er, more penetrating electrodes like E6010.

Use this mode for Air Carbon Arc(CAC− A) cutting and gouging. For best

results, adjust Arc Control to maximum.

239 083-A

2

1

3

8 5


36/150


8-3. Stick Welding Mode - SMAW/CAC-A Process

! Weld terminals are energized at alltimes in Stick welding mode.

1 Mode Switch

2 Left Display

3 Right Display

4 Adjust ControlSetup


Rotate Mode Switch to STICK position asshown.

The open circuit voltage is shown in the LeftDisplay and the preset amperage is shownin the Right Display.

Operation


If a remote control is plugged into the14−Pin receptacle, the remote will be a per-centage of the preset amperage. WhenConfiguration 2 or Configuration 3 are ac-tive, remote controls will be ignored andamperage will operate in panel only control.See section 8-5 for more information re-garding Alternate Configurations.

Adaptive Hot Start automatically increaseswelding amperage at the start of a weld.This helps eliminate electrode sticking dur-ing arc initiation.

For best results at the end of the weld, pull back the electrode quickly to extinguish the arc.

Arc Control (Dig)

Rotate Arc Control to select desired dig set-ting from 0 to 100.

Dig control allows the arc characteristics,soft versus stiff, to be changed for specificapplications and electrodes. Lower the dig

setting for smooth running electrodes likeE7018 and increase the dig setting for stiff-er, more penetrating electrodes like E6010.

Use this mode for Air Carbon Arc(CAC− A) cutting and gouging. For best

results, adjust Arc Control to maximum.

239 083-A

2 3

1

4

8 4. 5 8 5


37/150


8-4. Optional Low Open Circuit Voltage (OCV) Welding Modes

Low OCV Operation

The unit can be optionally config-ured for low open circuit voltage(OCV) operation in Stick andScratch Start TIG modes. When theunit is configured for low OCV op-eration only a low sensing voltage(approximately 15 VDC) is presentbetween the electrode and theworkpiece prior to the electrode

touching the workpiece. See Sec-tion 10-35 for information regardinghow to configure unit for low OCVwelding operation.

8-5. Alternate Configuration Functions

Configuration 1 is the default that the unit leaves the facto-ry set for. Stick mode recognizes a remote plugged intothe preset output set at the panel, CC mode displays pre-set panel control instead of the percentage of the remote.

Configuration 2 changes Stick modes remote operation.When configuration 2 is selected Stick mode operates inPanel Only control, meaning any remote control that isplugged into the remote 14 control will be ignored andhave no effect on the output. When Stick mode is active,a decimal point will be displayed in the amperage window.

Configuration 3 changes how the display works in the CCmode. When configuration 3 is selected the amperagewindow will display the percentage of preset amperagebeing set from the remote amperage control, the panel willset the maximum amperage. When CC mode is active, adecimal point will be displayed in the amperage window.

C 1

C 2

C 3

There are 3 ways that the remote control can be configured to operate on this machine. The configuration of the meters can be changed by placingthe process selection switch into Stick mode and turning the output on and off 3 −5 times within a few seconds, this can be done by triggeringa feeder or by activating the output on−off switch on a remote control. The amperage window will briefly display what mode is selected beforereturning to preset display


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SECTION 9 − THEORY OF OPERATION

Power Interconnect BoardPC2

Remote 14-Pin ReceptacleRC50

ArcControl

VoltmeterV

Ammeter A

Front Panel And Display Board PC3

Voltage/ Amperage

Adjust

ProcessSelectorSwitch

WeldProcessControl

Positive (+) Output Voltage Feedback

Negative (−) Output Voltage Feedback

Ribbon Cable

24 VAC

115 VAC

Boost Gate Signal

Optional Auxiliary Power

115 VACReceptacle

Input Boost InductorCurrent Feedback

Input Rectifier Voltage

Bus Voltage

CurrentTransformer

CT1

4 5 6

7 8

9

1 2 3

10

20

21 21

22 23

24

25 26

27

InverterModuleMod2

BusCapacitorsC12, C13

BoostSnubber

InductorL2

SnubberResistorModuleRM1

BoostInput

InductorL1

InputPre-Regulator

ModuleMod1

Power

SwitchS1

1 Phaseor

3 PhaseInput

Power

Effective with ME224001U,115 volts AC was removed

from RC50.


39/150


Weld Circuit

Optional

StickBoost

RectifierSR1

StickBoost

InductorL4

StickBoostRelayCR1

Main

TransformerT1

Output

Diodes D1 & D2

181716

1312

Series

CapacitorC15

11

OutputStabilizer

L3

Negative (−)Weld

Output

Receptacle

Work

1519

Positive (+)Weld

OutputReceptacleOutput

Current Sensor

HD1

1415

Electrode

OptionalGas

SolenoidGS1

FanMotor FM1

3536

Output Current Feedback

PrimaryHeatsink

ThermistorRT-2

SecondaryHeatsink

ThermistorRT-1

37 38

ControlTransformer

T2

SupplementaryProtector

CB1

32

33

34

115 VAC

24 VAC

34 VACCenterTapped

665VAC

Inverter Gating Signals

Main TransformerCurrent Feedback

BoostControl

ControlPower

Module

InverterControl

31

3029

28

Control BoardPC1

Primary Circuit

Control Circuit

115 VACSupplementary

Protector

CB2


40/150


Theory Of Operation Components

1 Primary Input Power

Single or Three-Phase AC primarypower supply.

2 Power Switch S1

Provides on/off control of primaryinput power to welding powersource.

3 Power Interconnect BoardPC2

Provides electrical connections forL1, L2, MOD1, MOD2, RM1, C12 &C13. Precharge and bleeder resis-tors and snubber capacitors aremounted on PC2.

4 Boost Input Inductor L1

Required to boost input rectifiervoltage to bus voltage.

5 Boost Snubber Inductor L2

Required to ensure soft−switching

of the boost IGBT located in MOD1.6 Inverter Module MOD2

Contains the main inverter IGBTs,snubber IGBTs, main boost diode,and two boost snubber diodes.

7 Input Pre−Regulator ModuleMOD1

Contains the input rectifier diodes,boost IGBT, and one boost snubberdiode.

8 Snubber Resistor ModuleRM1

Contains one boost snubber resis-

tor and one inverter snubber resis-tor.

9 Bus Capacitors C12 & C13

Stores energy and filters the DCbus voltage for input boost and in-verter.

10 Current Transformer CT1

Provides T1 current feedback toPC1. Used to protect inverterIGBTs in case of T1 primary over-current.

11 Series Capacitor C15

Provides protection against T1 sat-

uration. Saturation occurs whenthe voltage across the transformeris not balanced. The unbalancedvoltage appears as a DC offset volt-age across the transformer and cancause T1 primary overcurrent. Thecapacitor protects against this con-dition by blocking the DC offset.

12 Main Transformer T1

Switching action of IGBTs in MOD2creates the AC voltage source forT1 primary. T1 secondary outputssupply power to the weld circuit.

13 Output Diodes D1, D2

Rectifies the main secondary out-put of T1.

14 Output Current Sensor HD1

Provides weld output current feed-back to PC1.

15 Positive (+) and Negative (−)Weld Output Receptacles

Provide weld output and allowchanging of output polarity.

16 Stick Boost Relay CR1

Provides on/off control of Stickboost output circuit.

17 Stick Boost Inductor L4

Limits current in the Stick boost out-put circuit.

18 Stick Boost Rectifier SR1Rectifies the Stick boost secondaryoutput of T1.

19 Output Stabilizer L3

Filters or smooths the DC weld out-put current.

20 User Interface Board PC3

Consists of Voltmeter V, Ammeter A, Arc Control, Voltage/Amperage Adjust, Remote 14−pin receptacle,Process Selector Switch, and WeldProcess Control.

21 Voltmeter V, Ammeter A

See Sections 5-1, Front Panel Con-trols and 5-1, Meter Functions.

22 Arc Control

Controls Dig in Stick process or In-ductance in MIG process. SeeSection 5-1, Front Panel Controls.

23 Voltage/Amperage Adjust

Selects weld output voltage or am-perage level. See Section 5-1,Front Panel Controls.

24 Remote 14-Pin ReceptacleRC50

Provides connection for accessoryequipment. See Sections 5-1,Front Panel Controls, and 4-3, Re-mote 14 Receptacle Information.

25 Process Selector SwitchSelects weld process. See Section5-1, Front Panel Controls.

26 Weld Process Control

Controls weld output by automati-cally adjusting output current com-mand signal to Inverter Control.

27 Optional Auxiliary Power 115VAC Receptacle

Provides connection for auxiliaryequipment to welding powersource.

28 Control Board PC1

Contains the boost control, controlpower module, and inverter control.

29 Boost ControlControls switching of boost IGBT inMOD1 to regulate L1 current andthe DC bus voltage.

30 Control Power Module

Contains power supply for boostcontrol power, and inverter IGBTsto create AC voltage source for T2primary.

31 Inverter Control

Controls the main inverter andsnubber IGBTs within MOD2. Reg-ulates the weld output current to thevalue received from weld processcontroller. Provides power to PC3.Drives fan motor and gas valve.

Provides interface between prima-ry and secondary thermistors andPC3.

Effective with ME224001U,115 volts AC was removed from RC50.


Provides overload protection for re-mote 14-pin 115 VAC power, andoptional 115 VAC receptacle.


Provides overload protection for re-mote 14-pin 24 VAC power.

34 Control Transformer T2

Provides power to inverter controlon PC1, remote 14-pin receptacle,and optional 115 VAC receptacle.

35 Fan Motor FM1

Provides cooling of heatsinks andcomponents mounted inside windtunnel. The fan motor is thermostat-ically controlled and only runs whencooling is needed. Once unit iscooled to proper temperature, fanwill continue to run for ten minutes.

36 Optional Gas Solenoid GS1

Provides on/off flow of shieldinggas to the arc while TIG welding.

37 Secondary HeatsinkThermistor RT-1

Monitors temperature of secondaryheatsink for fan motor control andovertemperature shutdown.

38 Primary Heatsink ThermistorRT-2

Monitors temperature of primaryheatsink for fan motor control andovertemperature shutdown.


41/150


Notes

Over 80,000 trained

since 1930!400 Trade Square East, Troy, Ohio 45373

1-800-332-9448 www.weldin .or

Start Your Professional

Welding Career Now!


42/150


This circuit is for training purposes only.It has been modified for that use and maynot reflect the actual circuit for your unit.

9-1. Basic Training Circuit


43/150



44/150


SECTION 10 − TROUBLESHOOTING

10-1. Checking Unit Before Applying Power

See Section 10-18 for test points and values and Section13 for parts location.

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

See the Miller Extranet for service memos that may aid in the repair of this product.

! Measure voltage of input capacitors according to Section 10-2 and be sure voltage is near zero before touching any parts.

! Although control board PC1 and power interconnect board PC2 are briefly checked here, more complete tests may beneeded later for these parts. This procedure is simply to get a basic okay to power up unit.

The pre-power checks should be done if any of the following conditions exist:the symptoms are unknown;the unit is completely inoperative;visual damage is found on any of the following components: capacitors C12 and C13, control board PC1, modules MOD1 and MOD2 or intercon-

necting board PC2;there is no output or limited output.

Notes


45/150

PRE-POWER CHECKS


10-2. Measuring Input Capacitor Voltage

! Turn Off welding power source,and disconnect input power.

! Significant DC voltage canremain on capacitors after unit isOff. Always check the voltage asshown to be sure the input capac-itors have discharged beforeworking on unit.

Remove cover

1 Power Interconnect Board PC2

2 Voltmeter

3 Capacitor C12

Measure the DC voltage across C12(+) Positive Terminal and C12 (−) Neg-ative Terminal on PC2 as shown untilvoltage drops to near 0 (zero) volts.

4 Capacitor C13

Measure the DC voltage across C13(+) Positive Terminal and C13 (−) Neg-ative Terminal on PC2 as shown untilvoltage drops to near 0 (zero) volts.

If the capacitor voltage does not

drop to near zero after several min-utes, use a bleeder resistor of be-tween 25 and 1000 ohms, at least 5watts, #16 AWG 1000 volts DC insu-

lating rating wire to discharge thecapacitor(s) .

5 Typical Bleeder Resistor

An example of a typical bleeder resistoris shown on this page.

Proceed with pre-power checks.

1

2

Positive (+) lead to C12 (+) terminal,Negative (−) lead to C12 (−) terminal

3

1

2

Positive (+) lead to C13 (+) terminal,Negative (−) lead to C13 (−) terminal

4

Test Equipment Needed:

Typical Bleeder Resistor

25 to 1000 ohm,5 watt resistor

#16 AWG 1000 volts DCinsulation rating, approx.3 in. (76 mm) leads

5

Ref. 803 721-B / 907 161


46/150

PRE-POWER CHECKS


10-3. Input Pre-Regulator Module (MOD1)

Ref. 907 161 / 224 662-B

! Read and follow safetyinformation in Section 10-1before proceeding.

! Wear an earth groundedwrist strap when perform-ing pre-power and poweroff checks. Remove wriststrap before performingany checks or procedures

with power applied to themachine.

Board layout may differ fromthat shown.

1 MOD1

Visually inspect MOD1 for dam-age.

Check all measurements forMOD1. (see Section 10-4).

If any of the measurementsdo not read correctly, replaceMOD1 and MOD2. If an input SCR measures short also re-

place PC2.

MOD1 and MOD2 are differ-ent and must be installed inthe proper location.

Match the number on the side of each module to the number onPC2. MOD1 is skiip 83 HEC MOD2 is skiip 83 EC

The modules come as a kit with in-stallation instructions that need tobe followed entirely.

Continue to the end of thepre-power checks.

1


Component Side Of Board

−BUS

L1-L2

D12

TP1 AC1

L1

AC2

AC3

K A

RC3

10-4. Input Pre-Regulator Module (MOD1) Test Point Values

Input Pre-Regulator Module MOD1 DVM Positive Lead DVM Negative Lead DVM Diode DVM Ohms

Boost IGBT −BUS L1-L2 0.20 - 0.90 N/A

Boost IGBT (w/Plug Removed From RC3) D12 Left −BUS N/A 100k

Boost Snubber Diode L1-L2 TP1 0.20 - 0.90 N/A

Input SCR L1 AC1 OL N/A



Input Diode −BUS AC1 0.20 - 0.90 N/A



Input Pre-Regulator Module MOD1 IGBT Tester Positive Lead - RED IGBT Tester Negative Lead - BLACK Gate

Boost IGBT (w/Plug Removed From RC3) L1-L2 −BUS RC3-2


47/150

PRE-POWER CHECKS


10-5. Inverter Module (MOD2)

Ref. 907 161 / 224 662-B


! Wear an earth groundedwrist strap when performingpre-power and power offchecks. Remove wrist strapbefore performing anychecks or procedures with

power applied to the ma-chine.

Board layout may differ fromthat shown.

1 MOD2

Visually inspect MOD2 for damage.

Check all measurements for MOD2(see Section 10-6).

If any of the measurements do not read correctly, replaceMOD2, MOD1.

MOD1 and MOD2 are differ-ent and must be installed in

the proper location.Match the number on the side of each module to the number on PC2. MOD1 is skiip 83 HEC MOD2 is skiip 83 EC

The modules come as a kit with in-stallation instructions that need tobe followed entirely.



1

Component Side Of Board

HF-XFMR

TP3

L2

+BUS

−BUS

TP1

TP4

TP2

RC1

10-6. Inverter Module (MOD2) Test Point Values

Inverter Module MOD2 DVM Positive Lead DVM Negative Lead DVM Diode DVM Ohms

Boost Snubber Diode TP1 TP4 0.20 - 0.90 N/A

Boost Snubber Diode L2 TP4 0.20 - 0.90 N/A

Main Boost Diode TP4 +BUS 0.20 - 0.90 N/A

Inverter IGBT HF-XFMR +BUS 0.20 - 0.90 N/A

Inverter IGBT −BUS HF-XFMR 0.20 - 0.90 N/A

Snubber IGBT TP2 HF-XFMR 0.20 - 0.90 N/A

Snubber IGBT TP2 TP3 0.20 - 0.90 N/A

Inverter IGBT Gate (w/Plug Removed From RC1) RC1-1 HF-XFMR N/A 100k

Inverter IGBT Gate (w/Plug Removed From RC1) RC1-6 −BUS N/A 100k

Snubber IGBT Gate (w/Plug Removed From RC1) RC1-10 TP2 N/A 100k

Snubber IGBT Gate (w/Plug Removed From RC1) RC1-9 TP2 N/A 100k

Input Pre-Regulator Module MOD2 IGBT Tester Positive Lead - RED IGBT Tester Negative Lead - BLACK Gate

Inverter IGBT (w/Plug Removed From RC1) HF-XFMR −BUS RC1-6

Inverter IGBT (w/Plug Removed From RC1) +BUS HF-XFMR RC1-1

Snubber IGBT (w/Plug Removed From RC1) HF-XFMR D9 Left RC1-10

Snubber IGBT (w/Plug Removed From RC1) TP3 D9 Left RC1-9


48/150

PRE-POWER CHECKS


! Read and follow safety informationin Section 10-1 before proceeding.

! Wear an earth grounded wriststrap when performing pre-powerand power off checks. Removewrist strap before performing any

checks or procedures with powerapplied to the machine.

1 Power Interconnect Board PC2

2 MOD1 And MOD2 ConnectingScrews Initial Torque to (9 in. lbs (1N.m) Final Torque to (20 in. lbs (2.3

N.m) All other connecting screwstorque to (20 in. lbs (2.3 N.m)

Visually inspect PC2 for damage.

Check all measurements for PC2 (seeSection 10-8).

If any measurements failed, replacePC2 and bus capacitors.

10-7. Power Interconnect Board PC2

Ref. 907 161 / 224 662-B

1


R8R1

2

10-8. Power Interconnect Board PC2 Test Point Values

Power Interconnect Board PC2 DVM Positive Lead DVM Negative Lead DVM Diode DVM Ohms

Bleeder Resistor R1(Prior to LF278160)

Center Bus −BUS N/A 28k - 32k

Bleeder Resistor R1 (Eff W/LF278161) Center Bus −BUS N/A 37k - 41k

Bleeder Resistor R8(Prior to LF278160)

+BUS Center Bus N/A 28k - 32k

Bleeder Resistor R8 (Eff W/LF278161) +BUS Center Bus N/A 37k - 41k

Because R1 and R8 are connected to capacitors C12 and C13 the resistance measurements will require several minutes to complete. A moreprecise method would be to isolate R1 and R8 from the circuit. Perform this by removing the four connecting screws to C12 and C13 then slidepaper between the capacitors and PC2. If any of the measurements do not read correctly, replace PC2, capacitors C12 and C13. Continue tothe end of the pre-power checks.


49/150

PRE-POWER CHECKS


10-9. Control Board PC1

! Read and follow safety informationin Section 10-1 before proceeding.

! Wear an earth grounded wriststrap when performing pre-powerand power off checks. Removewrist strap before performing any

checks or procedures with powerapplied to the machine.

Remove all plugs from PC1 beforetesting.

1 Control Board PC1

Visually inspect PC1 for damage.

Check all measurements for PC1.(see Section 10-10).

If any of the measurements do not read correctly, replace PC1.


1

Test Equipment Needed:1

2

3

4

8

7

6

5

Pin sequence of IC chips.

D46

K A

R C 2

RC3

RC5

Ref. 242 814-C / 907 161

10-10.Control Board PC1 − Test Point Values

Pre-Regulator Control DVM Positive Lead DVM Negative Lead DVM Diode DVM Ohms

Buck IGBT D46 Anode RC2 Pin 1 0.20 - 0.90 N/ABuck Diode RC3 Pin 6 U6 Pin 5 0.20 - 0.90 N/A

Boost IGBT Gate Drive RC3 Pin 4 RC3 Pin 2 0.20 - 1.5 N/A

Boost IGBT Gate Drive RC3 Pin 4 RC3 Pin 3 N/A 1.9k - 2.1k

Boost IGBT Gate Drive RC3 Pin 3 RC3 Pin 4 0.20 - 0.90 N/A

60Hz Auxiliary Power Bridge DVM Positive Lead DVM Negative Lead DVM Diode DVM Ohms

Auxiliary Bridge IGBT RC5 Pin 3 RC2 Pin 1 0.20 - 0.90 N/A





50/150

PRE-POWER CHECKS


10-11. Power Switch (S1)

Ref. 907 161 / Ref. 183 484




1 Power Switch S1

Visually inspect S1 for damage.

Check switch mechanical opera-tion by turning switch On and Off several times. Switch should snapsharply between the On and Off positions.

Check switch electrical operationby checking continuity across S1contacts with switch in the On posi-tion. With switch in the Off position,ohmmeter should read open.

Replace switch if necessary.



1

Electrical Schematic


51/150

PRE-POWER CHECKS


10-12.Output Diodes D1, D2

Ref. 804 980-A / 804 979-ADiodes D1, D2

−

Weld OutputReceptacles

+




1 Diode D1

2 Diode D2

Visually inspect D1 and D2 for dam-age.

Check all measurements for outputdiodes D1 and D2 (see Section10-13).

If any of the measurements do not read correctly, replace bothD1 and D2.



2

1

10-13. Output Diodes D1, D2 Test Point Values

Output Diodes D1 And D2 DVM Positive Lead DVM Negative Lead DVM Diode DVM Ohms

D1 Terminal Anode Secondary Heatsink 0.10 - 0.90 N/A

D2 Terminal Anode Secondary Heatsink 0.10 - 0.90 N/A


52/150

PRE-POWER CHECKS


10-14. Stick Boost Rectifier (SR1)

Ref. 804 980-A / 804 979-A




1 Stick Boost Rectifier SR1

Visually inspect SR1 for damage.

Check all measurements for SR1(see Section 10-15).

If any of the measurements do not read correctly, replaceSR1.

! Pre-power checks are nowcomplete. Remove earthgrounded wrist strap beforeperforming any checks orprocedures with power ap-plied to the machine.


3

4

2

1

1

10-15. Stick Boost Rectifier (SR1) Test Point Values

Stick Boost Rectifier SR1 DVM Positive Lead DVM Negative Lead DVM Diode DVM Ohms

SR1 Terminal 2 Terminal 1 0.20 - 0.90 N/A





53/150

Always check unit before applying power (see Sections 10-1 thru10-10 ).


10-16. Troubleshooting Table

! Before connecting welding equipment to input (primary) power for servicing, be sure the input-power circuit protection is correctfor the welding equipment. Connect equipment to a dedicated circuit sized and fused for the rated output and duty cycle of thewelding equipment you are servicing. See the Electrical Service Guide section in this manual and National Electrical Code (NEC)article 630, Electric Welders.

! Remove earth grounded wrist strap before performing any checks or procedures with power applied to the machine.

See Section 10-18 for test points and values and Section 13 for parts location.

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

See the Miller Extranet for service memos that may aid in the repair of this product.

Trouble Remedy

No weld output; unit completelyinoperative.

Place line disconnect switch in On position (see Section 4-7 or 4-8).

Check and replace line fuse(s), if necessary, or reset circuit breaker (see Sections 4-7 and 4-8).

Check for proper input power connections and check condition of power cord(see Section 4-7 or 4-8).

Check continuity of Power switch S1 and replace if necessary (see Section 10-11).

Check control transformer T2 for signs of winding failure. Check continuity across windings, andcheck for proper connections. Check secondary voltages. Replace T2 if necessary.

Check control board PC1 and connections, and replace if necessary (see Power Off Checks in Sec-tions 10-22 thru 10-23, and also see Section 10-20).

Check power interconnect board PC2 and connections, and replace if necessary (see Power Off Checks in Sections 10-28 thru 10-29, and also see Section 10-26).

Check front panel/display board PC3 and connections, and replace if necessary (see Section 10-32).

No weld output; meter display On. Unit overheated and HELP 3 or HELP 5 screen is displayed. Allow unit to cool with fan On(see Section 10-17).

If a remote accessory is connected to remote 14 receptacle RC50:

Check accessory contact closure (continuity), and replace accessory if necessary.

Check accessory amperage control potentiometer resistance and connections,and replace accessory if necessary.

Check input and output voltages of hall device HD1 (see Section 10-18). Replace HD1 if necessary.

Check control board PC1 and connections, and replace if necessary (see Power Off Checks in Sec-tions 10-22 thru 10-23, and also see Section 10-20).

Check front panel/display board PC3 and connections, and replace if necessary (see Section 10-32).

Low weld output with no control. Check input and output voltages of hall device HD1 (see Section 10-18). Replace HD1 if necessary.

Check control board PC1 and connections, and replace if necessary (see Power Off Checks in Sec-tions 10-22 thru 10-23, and al

xmt350cccvauto line (le073174)

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