Lincoln Electric V250-S - page 40

F-8

TROUBLESHOOTING & REPAIR

F-8

INVERTEC V250-S

Observe all Safety Guidelines detailed throughout this manual

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric

Service Department for technical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.

CAUTION

OUTPUT PROBLEMS

PROBLEMS

(SYMPTOMS) POSSIBLE AREAS OF

MISADJUSTMENT(S) RECOMMENDED

COURSE OF ACTION

The machine will not produce more

than 200 amps. 1. This may be normal operation. If

the output current exceeds 290

amps, an electronic protection

circuit will reduce the current to

less than 200 amps. The

machine will continue to produce

this low current until the

protection circuit is reset. Reset

occurs when the output load is

removed.

2. Check the input voltage and input

voltage reconnect procedures.

See

Input Voltage Reconnect

Procedure

.

3. Check for loose or faulty welding

cables.

1. Perform the

Output Diode Test

.

2. The control board may be faulty.

Replace.

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Contents

Main INVERTEC V250-S SERVICE MANUAL SVM124-A FOR ENGINE powered equipment. i WARNING ELECTRIC AND MAGNETIC FIELDS may be dangerous ii ARC RAYS can burn. ELECTRIC SHOCK can kill. FUMES AND GASES can be dangerous. FOR ELECTRICALLY powered equipment. CYLINDER may explode if damaged. iii WELDING SPARKS can cause fire or explosion. iv PRCAUTIONS DE SRET PRCAUTIONS DE SRET POUR LES MACHINES SOUDER TRANSFORMATEUR ET REDRESSEUR vi MASTER TABLE OF CONTENTS FOR ALLSECTIONS SECTION-A-1 TABLE OF CONTENTS -INSTALLATION SECTION- A-2 Technical Specifications - Invertec V250-S A-2 OUTPUT PHYSICAL DIMENSIONS INPUT SAFETY PRECAUTIONS ELECTRIC SHOCK SELECT SUITABLE LOCATION STACKING TILTING INPUT VOLTAGE RECONNECT PROCEDURE RECONNECT PROCEDURE 'A' A-5 + OUTPUT CONNECTIONS REMOTE CONTROL RECEPTACLE OUTPUT CABLES QUICK DISCONNECT PLUGS Page SECTION-B-1SECTION-B-1 TABLE OF CONTENTS -OPERATION SECTION- B-2 GENERAL DESCRIPTION OPERATIONALFEATURES WELDING CAPABILITY LIMITATIONS SAFETY INSTRUCTIONS - B-3 + I O CONSTANT CURRENT PROCESSES MANUAL ARC WELDING (STICK) AIR CARBON ARC CUTTING TIG WELDING B-5 PARALLEL OPERATION OVERLOAD PROTECTION THERMAL PROTECTION Page SECTION C-1 ACCESSORIES SECTION C-1 TABLE OF CONTENTS -ACCESSORIES SECTION- C-2 ACCESSORIES C-2 OPTIONS / ACCESSORIES CABLE PLUGS REMOTE CONTROLS Page D-2 INPUT FILTER CAPACITOR DISCHARGE PROCEDURE ELECTRIC SHOCK D-3 ROUTINE MAINTENANCE FILTER CAPACITOR CONDITIONING D-4 TABLE OF CONTENTS -THEORY OF OPERATION SECTION- E-2 CONTROL BOARD SHUNT INPUT LINE VOLTAGE FIGURE E.1 - INPUT VOLTAGE CIRCUITS LINE SWITCH RECTIFIER AUXILIARY PRECHARGE AND PROTECTION IGBT Operation Discussion and diagrams MAIN TRANSFORMER E-5 CONTROL BOARD SHUNT OUTPUT RECTIFICATION AND CONTROL IGBT Operation Discussion in this section. FIGURE E.4 OUTPUT RECTIFICATION AND CONTROL LINE SWITCH PROTECTION CIRCUITS OVERLOAD PROTECTION THERMAL PROTECTION INSULATED GATE BIPOLAR TRANSISTOR (IGBT) OPERATION PULSE WIDTH MODULATION MINIMUM OUTPUT MAXIMUM OUTPUT TABLE OF CONTENTS -TROUBLESHOOTING & REPAIR SECTION- Step 1. LOCATE PROBLEM (SYMPTOM). Step 2. PERFORM EXTERNAL TESTS. Step 3. RECOMMENDED COURSE OF ACTION HOW TO USE TROUBLESHOOTING GUIDE OSCILLOSCOPE WARNING _______________________________ PC BOARD TROUBLESHOOTING PROCEDURES F-4 Input Voltage Reconnect F-5 Voltage Checks Input Filter Capacitor Conditioning Protection Circuit Control Board Voltage Checks F-6 Capacitor Balance Test Input Voltage Reconnect Procedure F-7 Resistance Test Input Rectifier Test Installation Section Protection Circuit Page F-9 WELDING PROBLEMS Installation Section Control Board Voltage Page AUXILIARY TRANSFORMER TEST Table F.1 AUXILIARY TRANSFORMER TEST (continued) 1J7 2J7 3J7 4J7 5J7 6J7 Figure F.1 Auxiliary Transformer and Plug J7. AUXILIARY TRANSFOMER PLUG J7 AUXILIARY TRANSFORMER TEST (continued) TABLE F.1 Auxiliary Transformer Test Points Page Page Page Power Board Resistance Input Rectifier Bridge Removal And Replacement INPUT RECTIFIER TEST (continued) TABLE F.2 Input Rectifier Test Points Page Page POWER BOARD RESISTANCE TEST (continued) + Figure F.3 Power Board Test Points. + Removal and Replacement Power Board Voltage Test POWER BOARD RESISTANCE TEST (continued) TABLE F.3 Power Board Resistance Test Points. Page Page OUTPUT DIODES TEST (continued) - Figure F.4 Machine Output Terminals. INVERTEC V250-S + I - Figure F.5 Meter Probes. INVERTEC V250-S O I DIODE MODULES POWER BOARD VOLTAGE TEST Table F.4 POWER BOARD VOLTAGE TEST (continued) + + PLUG J6 Figure F.8 Plug J6 on Power Board #308 (1J6) #307 (2J6) POWER BOARD VOLTAGE TEST (continued) TABLE F.4. Power Board Voltage Test Points. TEST POINTS ACCEPTABLE VOLTAGES TEST CONDITIONS Page CONTROL BOARD VOLTAGE TEST Filter Capacitor Discharge Procedure Table F.5 CONTROL BOARD VOLTAGE TEST (continued) G2666-[ ] Figure F.9 Plugs J1-J5 on Control Board V250S CONTROL CONTROL BOARD VOLTAGE TEST (continued) TABLE F.5. Control Board Voltage Test Points. TEST POINTS ACCEPTABLE VOLTAGES TEST CONDITIONS Page PROTECTION CIRCUIT TEST PROTECTION CIRCUIT TEST (continued) 1J2 Figure F.11 PLUG J6 8J2 6J2 PROTECTION CIRCUIT TEST (continued) PROTECTION CIRCUIT (SIMPLIFIED) Page CAPACITOR BALANCE TEST CAPACITOR BALANCE TEST (continued) + Figure F.12 Power Board and Capacitor Test Locations + CAPACITOR (C2) TERMINALS CAPACITOR (C1) TERMINALS maintenance CAPACITOR BALANCE TEST (continued) TABLE F.6 Capacitor Voltages Page CONTROL BOARD REMOVALAND REPLACEMENT CONTROL BOARD REMOVALAND REPLACEMENT (continued) DEPRESS LOCKING TAB ON MOUNTING PIN Figure F.13 SIX MOUNTING TABS POWER BOARD REMOVALAND REPLACEMENT POWER BOARD REMOVALAND REPLACEMENT (continued) 204 Figure F.14 + 4 SOCKET HEAD CAP SCREWS Filter Capacitor Removal and Replacement POWER BOARD REMOVALAND REPLACEMENT (continued) Page FILTER CAPACITOR REMOVAL AND REPLACEMENT FILTER CAPACITOR REMOVAL AND REPLACEMENT (continued) Replacement Procedure FILTER CAPACITOR REMOVALAND REPLACEMENT (continued) Page INPUT RECTIFIER BRIDGE REMOVALAND REPLACEMENT Page INPUT RECTIFIER BRIDGE REMOVALAND REPLACEMENT (continued) Page Page Figure F.15 SLEEVED SPLICES SNUBBER RESISTORS 7/16 BOLT Figure F.17 Output Diode Assembly and Leads Figure F.15 Figure F.17 LOCKING TABS Figure F.18 Heatsink Removal Page Page DIODE MODULES 7/16 BOLTED CONNECTIONS Figure F.19 Output Diode Assembly and Leads 7/16 MOUNTING BOLTS Page Page Page 201 204 205 Figure F.20 Main Transformer Right Side 208 T3 CURRENT TRANSFORMER MAIN TRANSFORMER Figure F.22 MAIN TRANSFORMER SECONDARY LEADS Figure F.21 Main Transformer Left Side MOUNTING SCREWS LOCKING MOUNTING TABS Figure F.22 Main Transformer Mountings (MACHINE CODES BELOW 10150) Page Page Figure F.24. 201 204 205 Figure F.23 Main Transformer Right Side 208 T3 CURRENT TRANSFORMER MAIN TRANSFORMER Figure F.25 MAIN TRANSFORMER SECONDARY LEADS Figure F.24 Main Transformer Left Side MOUNTING SCREWS LOCKING MOUNTING TABS Figure F.25 Main Transformer Mountings Page Page RETEST AFTER REPAIR Page Page Page G-2 Wiring Diagram (Codes 10102, 10103) - CLEVELAND, OHIO U.S.A. + ARC - ARC 8-5-94 L9280 A B CD + F + ARC - ARC 9-29-95E L9907 A B CD + F G-4 Control PC Board (G2666) Layout G2666 G2666 R46 G-4 G-5 Power PC Board (G2684) Layout G2684 POWER P.C. BD. AS'BLY A1 G-5 G-6 Control PC Board (G2666) Schematic 2 4 OPEN G-6 G-7 Power PC Board (G2684) Schematic LC R74 R50 G-7