Lincoln Electric V250-S specification

D-2

MAINTENANCE

D-2

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WARNING

ELECTRIC SHOCK can kill.

•Have an electrician install and service this equipment.

•Turn the input power off at the fuse box before working on equipment.

•Do not touch electrically hot parts.

•Prior to Performing preventative main- tenance, perform the following capaci- tor discharge procedure to avoid elec- tric shock.

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INPUT FILTER CAPACITOR

DISCHARGE PROCEDURE

1.Turn off input power or disconnect input power lines.

2.Remove the 5/16" hex head screws from the side and top of the machine and remove wrap-around machine cover.

3.Be careful not to make contact with the capacitor terminals that are located in the top and bottom of the Power Board.

4.Obtain a high resistance and high wattage resistor (25-1000 ohms and 25 watts minimum). This resis- tor is not supplied with machine. NEVER USE A SHORTING STRAP FOR THIS PROCEDURE.

5.Locate the four capacitor terminals (large hex head cap screws) shown in Figure D.1. One pair at the top and one pair at the bottom of the Power Board.

6.Use electrically insulated gloves and insulated pli- ers. Hold body of the resistor and connect resistor leads across the two capacitor terminals. Hold resistor in place for 10 seconds. DO NOT TOUCH CAPACITOR TERMINALS WITH YOUR BARE HANDS.

7.Repeat discharge procedure for the capacitor on other two terminals.

8.Check voltage across terminals of all capacitors with a DC voltmeter. Polarity of capacitor terminals is marked on PC board above terminals. Voltage should be zero. If any voltage remains, repeat this capacitor discharge procedure.

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FIGURE D.1 — LOCATION OF INPUT FILTER CAPACITOR TERMINALS.

POWER	UPPER
BOARD	CAPACITOR TERMINALS

	LOWER
	CAPACITOR
	TERMINALS
	POWER
	RESISTOR
RIGHT SIDE OF MACHINE	INSULATED
	PLIERS

INSULATED

GLOVES

INVERTEC V250-S

Image 22

Lincoln Electric V250-S service manual Input Filter Capacitor Discharge Procedure

Contents

Invertec V250-S Safety ARC Rays can burn Electric Shock can killFumes and Gases can be dangerous Cylinder may explode if damaged Welding Sparks can cause fire or explosion Précautions DE Sûreté Sûreté Pour Soudage a L’Arc Master Table of Contents for ALL Sections Installation Table of Contents Installation Section Three Phase Single Phase Technical Specifications Invertec V250-SThree Phase Input Connections Safety PrecautionsSelect Suitable Location Input Fuse and Supply Wire Input Voltage Reconnect ProcedurePower Input Connection for 50/60 HZ Machines Quick Disconnect Plugs Remote Control ReceptacleOutput Connections Output Cables Invertec V250-S Operation Safety Instructions Gouging Sparks Controls and Settings Figure B.1 Case Front Controls AIR Carbon ARC Cutting Constant Current ProcessesManual ARC Welding Stick TIG Welding Overload Protection Parallel OperationThermal Protection Invertec V250-S Accessories Table of Contents Accessories Section Remote Controls Options / AccessoriesCable Plugs Maintenance Table of Contents Maintenance Section Input Filter Capacitor Discharge Procedure Figure D.1 Location of Input Filter Capacitor Terminals Routine Maintenance Filter Capacitor Conditioning Figure D.2 Location of Maintenance Components Table of Contents Theory of Operation Section Theory of Operation General Description Input Line Voltage Precharge and Protection Figure E.2 Protection and PRE-CHARGE Circuits Main Transformer Figure E.3 Main Transformer Output Rectification Control Figure E.4 Output Rectification and Control Protection Circuits Overload Protection Insulated Gate Bipolar Transistor Igbt Operation Minimum Output Pulse Width ModulationMaximum Output Troubleshooting & Repair HOW to USE Troubleshooting Guide Oscilloscope Warning PC Board Troubleshooting Procedures Board can be dam- aged by static electricity Possible Areas Recommended Symptoms Course of Action Possible Areas Perform the Control Board Voltage Checks Capacitor Balance Test Troubleshooting & Repair Perform the Output Diode Test Welding Problems Invertec V250-S Test Description Auxiliary Transformer TestMaterials Needed Test Procedure Auxiliary Transformer Test Auxiliary Transformer Test Table F.1 Auxiliary Transformer Test Points Invertec V250-S Input Rectifier Test Test Procedure Input Rectifier Test Table F.2 Input Rectifier Test Points Test Point Terminals Analog Meter X10 Range Invertec V250-S Power Board Resistance Test Power Board Resistance Test Test Description Power Board Resistance Test Table F.3 Power Board Resistance Test Points Invertec V250-S Output Diodes Test Output Diodes Test Figure F.4 Machine Output Terminals Invertec V250-S Diode Modules Power Board Voltage Test Power Board Voltage Test Figure F.8 Plug J6 on Power Board Acceptable Test Description Table F.4. Power Board Voltage Test PointsTest Conditions Invertec V250-S Control Board Voltage Test Control Board Voltage Test Figure F.9 Plugs J1-J5 on Control Board Table F.5. Control Board Voltage Test Points 18VAC Invertec V250-S Protection Circuit Test Protection Circuit Test Figure F.10 Control Board Plug J2 Test Points Protection Circuit Simplified Invertec V250-S Capacitor Balance Test Figure F.12 Power Board and Capacitor Test Locations Capacitor Balance Test Table F.6 Capacitor Voltages Invertec V250-S Control Board Removal and Replacement Procedure Control Board Removal and ReplacementV250S Control Power Board Removal and Replacement Power Board Removal and Replacement Figure F.14 Power Board Lead Locations Power Board Replacement Procedure Invertec V250-S Filter Capacitor Removal and Replacement Matched Parts Filter Capacitor Removal and Replacement Figure F.15 Heatsink/Power Board Removal Perform Power Board Replacement Procedure in this section Invertec V250-S Input Rectifier Bridge Removal and Replacement Input Rectifier Bridge Removal and Replacement Figure F.16 Input Rectifier Lead Locations Troubleshooting & Repair Invertec V250-S Materials Needed Snubber Resistors Locking Tabs Invertec V250-S Wrench Allen type wrench Torque wrench Mounting Bolts Diode Modules Bolted Connections Troubleshooting & Repair Invertec V250-S Main Transformer Removal and Replacement Machine Codes below T3 Current Transformer Main Transformer Main Transformer Secondary Leads Figure F.22 Main Transformer Mountings Clear all leads and secure for case wrap-around assembly Invertec V250-S Main Transformer Removal and Replacement Machine Codes Above Figure F.23 Main Transformer Right Side Figure F.24 Main Transformer Left Side Figure F.25 Main Transformer Mountings Troubleshooting & Repair Invertec V250-S Retest After Repair Maximum Acceptable Output AT Minimum Output SettingsMinimum Acceptable Output AT Maximum Output Settings Input Idle Amps and Idle Watts Invertec V250-S Electrical Diagrams Invertec V250-S Wiring Diagram Codes 10102 Invertec V250S Wiring Diagram Codes 10187 Return to Section Control PC Board G2666 Layout G2666 Power PC Board G2684 Layout Power P.C. BD. Asbly Control PC Board G2666 Schematic Relay Coils Power PC Board G2684 Schematic From Control BD