Thermadyne CutMaster 75 User manual

Service Manual
Plasma Cutting
Power Supply
CutMaster™ 75
CE CutMaster™ 75
March 22, 2004 Manual No. 0-2869
A-02990

Plasma Cutting Power Supply
CutMaster™ 75
CE CutMaster™ 75
Service Manual Number 0-2869
Published by:
Thermal Dynamics Corporation
82 Benning Street
West Lebanon, New Hampshire, USA 03784
[phone]
www.thermal-dynamics.com
Copyright 2001 by
Thermal Dynamics Corporation
All rights reserved.
Reproduction of this work, in whole or in part, without written per-
mission of the publisher is prohibited.
The publisher does not assume and hereby disclaims any liability to
any party for any loss or damage caused by any error or omission in
this Manual, whether such error results from negligence, accident, or
any other cause.
Printed in the United States of America
Publication Date: Date: March 22, 2004
RecordthefollowinginformationforWarrantypurposes:
Where Purchased:____________________________________
Purchase Date:_______________________________________
Power Supply Serial #:________________________________
Torch Serial #:________________________________________
WARNINGS
Read and understand this entire Manual and your employer’s safety practices before installing, oper-
ating, or servicing the equipment.
While the information contained in this Manual represents the Manufacturer's best judgement, the
Manufacturer assumes no liability for its use.

TABLE OF CONTENTS
SECTION1:
GENERALINFORMATION ................................................................................................ 1-1
1.01 Notes,CautionsandWarnings ...................................................................... 1-1
1.02 Important Safety Precautions ....................................................................... 1-1
1.03 Publications.................................................................................................. 1-2
1.04 Note, Attention et Avertissement .................................................................. 1-3
1.05 PrecautionsDe SecuriteImportantes ........................................................... 1-3
1.06 DocumentsDeReference ............................................................................. 1-5
1.07 Declaration of Conformity ............................................................................. 1-7
1.08 StatementofWarranty .................................................................................. 1-8
SECTION2:
INTRODUCTION ............................................................................................................... 2-1
2.01 ScopeOf Manual.......................................................................................... 2-1
2.02 GeneralServicePhilosophy.......................................................................... 2-1
2.03 ServiceResponsibilities................................................................................ 2-1
SECTION3:
DESCRIPTION.................................................................................................................. 3-1
3.01 Scope........................................................................................................... 3-1
3.02 General Description ...................................................................................... 3-1
3.03 Specifications/DesignFeatures .................................................................... 3-1
3.04 Power Supply Options and Accessories ....................................................... 3-2
SECTION4:
SERVICETROUBLESHOOTING DIAGNOSTICS.............................................................. 4-1
4.01 Introduction................................................................................................... 4-1
4.02 Periodic Inspection & CleaningProcedures................................................... 4-1
4.03 SystemTheory ............................................................................................. 4-1
4.04 Common OperatingProblems ....................................................................... 4-2
4.05 TroubleshootingGuide -GeneralInformation................................................. 4-3
4.06 Circuit Fault Isolation .................................................................................... 4-4
4.07 MainInput and Internal PowerProblems....................................................... 4-5
4.08 Pilot Arc Problems........................................................................................ 4-8
4.09 Main Arc Problems ......................................................................................4-10
4.10 TestProcedures...........................................................................................4-10
SECTION5:
SERVICE .......................................................................................................................... 5-1
5.01 Scope........................................................................................................... 5-1
5.02 Anti-Static Handling Procedures ................................................................... 5-1
5.03 Parts Replacement - GeneralInformation ..................................................... 5-1
5.04 MajorExternal Parts Replacement ............................................................... 5-2
5.05 Front Panel PartsReplacement..................................................................... 5-3
5.06 LeftSide Internal Component PartsReplacement......................................... 5-4
5.07 Rear Panel Parts Replacement ..................................................................... 5-7
5.08 RightSideInternalComponentPartsReplacement....................................... 5-9

TABLE OF CONTENTS (continued)
SECTION6:
PARTS LISTS ................................................................................................................... 6-1
6.01 Introduction................................................................................................... 6-1
6.02 OrderingInformation ..................................................................................... 6-1
6.03 MajorExternalReplacementParts ............................................................... 6-2
6.04 Front PanelReplacement Parts..................................................................... 6-3
6.05 LeftSide InternalReplacement Parts ........................................................... 6-4
6.06 RearPanelReplacementParts ..................................................................... 6-6
6.07 RightSide InternalReplacement Parts ......................................................... 6-8
6.08 Options and Accessories.............................................................................6-10
APPENDIX1: INPUTWIRING REQUIREMENTS ..................................................................... A-1
APPENDIX 2: SEQUENCE OF OPERATION (BLOCK DIAGRAM) ........................................... A-2
APPENDIX 3: LOGIC PC BOARD LAYOUT .............................................................................. A-3
APPENDIX 4: MAIN POWER PC BOARD LAYOUT.................................................................. A-4
APPENDIX 5-A: 208/230VOLT MAIN PC BOARDWIRING ...................................................... A-6
APPENDIX 5-B: 400-V 460-V, and 600-V MAIN PC BOARDWIRING ....................................... A-7
APPENDIX 6: CD PC BOARD LAYOUT .................................................................................... A-8
APPENDIX 7: LED/POT PC BOARD LAYOUT .......................................................................... A-9
APPENDIX 8: IGBT CIRCUIT PC BOARD LAYOUT ............................................................... A-10
APPENDIX 9: INPUT DIODE PC BOARD LAYOUT ................................................................ A-11
APPENDIX 10: OUTPUT DIODE PC BOARD LAYOUT .......................................................... A-12
APPENDIX11:POWEROUTPUT PCBWIRINGDIAGRAM.................................................... A-13
APPENDIX 12: 28VAC CIRCUIT DIAGRAM ........................................................................... A-14
APPENDIX13: MAINTENANCESCHEDULE ......................................................................... A-15
APPENDIX 14: SYSTEM SCHEMATIC, 208/230-VOLT UNITS ............................................... A-16
APPENDIX 15: SYSTEM SCHEMATIC, 400-V, 460-V UNITS ................................................. A-18
APPENDIX 16: SYSTEM SCHEMATIC, 600-V UNITS............................................................ A-20