Lincoln Electric SVM149-A service manual IGBT’s

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F-13		TROUBLESHOOTING & REPAIR	F-13

MAIN INVERTER BOARD RESISTANCE TEST (continued)

8.Check the IGBTs for “shorts”. Check each IGBT (6) from Gate to Collector. Normal resistance is approx- imately 100 ohms.

Also check each device from Gate to Emitter. Normal resistance is approximately 40 ohms.

Check each device from Emitter to Collector. Normal reading is high resistance in one polarity and a low resistance in the opposite polarity.

Note: These devices will usually fail “short”resulting in a zero or very low resistance reading. If they “open” physical damage should be evident.

FIGURE F.3 LOCATION OF IGBTS (6)

LEAD 2 (NZL)

WRK

LEAD 3 (EL)

Plug J1

IGBT’s

(6)

Harness

Plug

RIGHT SIDE OF MACHINE

GCE

PRO-CUT 25

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Contents PRO-CUT Safety Cylinder may explode if damaged Précautions DE Sûreté SafetyMaster Table of Contents for ALL Sections PRO-CUT Installation Section Table of ContentsTechnical Specifications PRO-CUT 25 K1756-1 InstallationInput Electrical Connections Safety Precautions Electric Shock can KillSelect Proper Location High Frequency Interference ProtectionGAS Input Connections Torch Output ConnectionsPRO-CUT Table of Contents Operation Section Description Safety PrecautionsPreheat Temperature for Plasma Cutting OperationUser Responsibility Operational Features and ControlsDesign Features Advantages Consumable Life Cutting CapabilityLimitations Controls and SettingsPilot ARC Discussion Apparently wrong, reset the machine by turningGeneral In All Cases Procedure RecommendationsPRO-CUT Accessories General Options Accessories Maintenance Electric Shock can kill Routine MaintenancePRO CUT PRO-CUT Table of Contents Theory of Operation Section Input Line VOLTAGE, and Auxiliary Transformer Theory of OperationGeneral Description Figure E.3 Precharge and Protection Precharge and ProtectionReturn Return to Section TOC Main TransformerFigure E.5 Plasma Output Section and Torch Figure E.6 Control Board Control BoardAccidental Operation Protection Safety PARTS-IN-PLACE ProtectionProtection Circuits Insulated Gate Bipolar Transistor Igbt Operation Table of Contents Troubleshooting & Repair Section HOW to USE Troubleshooting Guide Troubleshooting & RepairPC Board Troubleshooting Procedures Output Problems Function Problems See the Operation section Troubleshooting & Repair LED Function Problems Description Input Filter Capacitor Discharge ProcedureRight Side of Machine Discharge ProcedureMain Inverter Board Resistance Test Right Side of Machine IGBT’s D2 D1 D11 D10 PRO-CUT Input Board Voltage Test Test Points Fan PRO-CUT Main Inverter Board Voltage Test P2 P1 P2 P1 PRO-CUT Torch Continuity and Solenoid Test Torch Continuity and Solenoid Test Torch Continuity and Solenoid Test PRO-CUT AIR/GAS Solenoid Test AIR/GAS Solenoid Test Control Board Removal and Replacement Small Red Cap Screws Over tighten Input Board Removal and Replacement Input Board Input Board Removal & Replacement PRO-CUT Main Inverter Board Removal and Replacement Main Board Main Inverter Board Removal & Replacement PRO-CUT Switch Removal and Replacement PRO FAN Removal and Replacement Fan Do Not Over tighten Machine Input and Output Retest After RepairTable of Contents Electrical Diagrams Section Electrical DiagramsInput Voltage Board Pressure SCHEMATIC- Control Printed Circuit Board Sheet Electrical Diagrams Electrical Diagrams PC Board Assembly Main Inverter Board PC Board Assembly Input Board Cutting Current Path SVM Error Reporting Form