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Troubleshooting guide

Ver 1.0

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Summary of Contents for Kemppi miniarc 140

  • Page 1: Troubleshooting Guide

    Troubleshooting guide Ver 1.0...
  • Page 2: Table Of Contents

    Contents Technical data………………………………………. Operation principal………………………………….. Main circuit…………………………………………. Troubleshooting chart……………………….…...…. Main circuit diagrams………………………………. Functional tests/measurings…………....……. 7, 8 Measuring points…………...……...….. 8, 9 Main transformer T001 prim. Voltage... 9, 10 Main transformer T001 sec. Voltage..10, 11 Voltage after secondary rectifier…..11-13 IGBT gate pulse…………………..…... Control card A001 connectors…………………...….
  • Page 3: Technical Data

    Technical data Minarc 140 Minarc 110 Supply voltage, 1~50/60 Hz 220 V –10%…240 V +6% 220 V –10%…240 V +6% Loadability 35%ED 140 A (7,5 kVA) 50%ED 110 A (5,5 kVA) 100%ED 100 A (5,1 kVA) 80 A (3,9 kVA) Connection cable / fuses 2.5 mm²...
  • Page 4: Operation Principal

    Operating principal Minarc power sources are ”dual-Forward”-inverter power sources, controlled by PWM method. The switching components are IGBT-transistors. Inverter operating frequency is approx. 80 kHz. Below is a picture of the ”dual-forward”-inverter operating principal: n. + 320 V 13µs When IGBT-transistors V1 and V2 are not conductive, no power is transferred. The power is adjusted by changing the IGBT-transistors conductive timings (PWM).
  • Page 5: Troubleshooting Chart

    General Machine repairs may only be done by a company or repairman authorized to do the work! First check visually if there are any signs of damage in the machine, for example loose wires, breaks or signs of overheating. Troubleshooting chart DISTURBANCE POSSIBLE CAUSE REMEDY...
  • Page 6: Main Circuit Diagrams

    Main circuit diagrams Main circuit diagram, before serial number 1085088/M (OCV approx. + 105 V) Main circuit diagram from serial number 1085088/M onwards (OCV approx. + 85 V)
  • Page 7: Functional Tests/Measurings

    Functional tests / measurings Measuring point 1. Main transformer T001 primary voltage Measuring point 2. Main transformer T001 secondary voltage Measuring point 3. Voltage after the secondary rectifier...
  • Page 8: Measuring Points

    Measuring points on the control card A001 Measuring point 1. Main tranformer T001 primary voltage Main tranformer T001 primary voltage, 10 A...
  • Page 9: Main Transformer T001 Sec. Voltage

    Measuring point 1. Main transformer T001 primary voltage Päämuuntajan T001 ensiöjännite, 140 A Measuring point 2. Main transformer T001 secondary voltage Main tranformer T001 secondary voltage, 10 A...
  • Page 10: Voltage After Secondary Rectifier

    Measuring point 2. Main transformer T001 secondary voltage Main transfomer T001 secondary voltage, 140 A Measuring point 3. Voltage after secondary rectifier Voltage after the secondary rectifier, 10 A...
  • Page 11: Igbt Gate Pulse

    Measuring point 3. Voltage after the secondary rectifier Voltage after the secondary rectifier, 140 A Measuring point 4. IGBT gate pulse IGBT gate pulse, 10 A...
  • Page 12 Measuring point 4. IGBT gate pulse IGBT gate pulse, 60 A IGBT gate pulse, 140 A...
  • Page 13: Igbt Gate Pulse

    Measuring point 4. IGBT gate pulse IGBT gate pulse with open circuit (OCV approx. + 105 V) IGBT gate pulse with open circuit (OCV approx. + 85 V)
  • Page 14: Control Card A001 Connectors

    Control card A001 connectors X004 X23 X10 Connector Signal X1, X2 Net voltage 230 Vac Protective earth X4, X6, X8 Current adjustment potentiometer R001 X5, X7 MMA/TIG-selection switch S002 X9, X11 Main transformer T001 auxiliary coil X10, X12 Main transformer T001 PTC RT101 X13, X14 Primary profile PTC RG201...
  • Page 15: Control Card A001 Layout

    Control card A001 layout The older version control card A001, 4292730 The new control card A001, 4298870...
  • Page 16: Control Card A001 Layout

    Control card A001 layout IGBTs and opposite diodes Varistors (IGBT-set 4297750) (95 V 9753590, 175 V 9753588) (9775757) Rectifier unit Intermediate circuit charging EMI-filter (9750191) (Rele 9766230)
  • Page 17: Igbt-Transistor Testing

    IGBT-transistors testing Discrete-IGBT (50 A, 600 V) can be tested with the IGBT-tester. When replacing damaged IGBT-transistors the whole set must be always replaced. The gate resistors (10Ω) must be checked and replaced if necessary. Spare part IGBT set 4297750. Discrete-IGBT tightening torque to the heatsink is 0,6…1,2 Nm! B1/4 Testing the secondary diodes...
  • Page 18: Service Infos

    Service infos 02 / 2002 Minus pole insulator Power sources Minarc 110 & 140 Modification An insulator 9771963 is added to the minus-pole. See the attached picture. Reason for midification Secondary choke may cause a short circuit between plus- and minus-poles. This is prevented by installing the inslulator 9771963 to the minus-pole.
  • Page 19 Service infos 03 / 2002 IGBT gate resistors and intermediate circuit charging relay Power sources Minarc 110 & 140 Modification IGBT gate resistors (10 ohm.) have been added to the spare part set (4297750). Reason for modification If the IGBTs are damaged, also the gate resistors (R2, R4, R5, R6, R7 and R8) may be damaged. For example if one resistor has been destroyed, then the IGBT doesn´t get gate control and this causes overload to the other IGBTs.
  • Page 20 Service infos 20 / 2002 A new control cardi A001 and filter card Z001 Power sources Minarc 110 and 140 Modification Control card A001 and filter card Z001 have been replaced with new versions. The new spare part codes are as follows: Power source Control card A001 Filter card Z001...
  • Page 21: Notes

    Notes...

This manual is also suitable for:

Miniarc 110

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