Lincoln Electric SVM188-A service manual Replacement Procedure

Page 83

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F-43

TROUBLESHOOTING AND REPAIR

F-43

SCR RECTIFIER BRIDGE

REMOVAL AND REPLACEMENT PROCEDURE (cont.)

FIGURE F.18 – RECTIFIER REPLACEMENT

Thread Forming Screw

Plain Washer

5/16-18 Hex Nut

Negative Output Lead

Choke Lead

 

 

 

 

 

Insulator

Lock Washer

Plain Washer

Output Snubber Lead

 

 

 

Lock Washer

 

Bridge Mounting

Transformer

‘A’ Lead from

 

Secondary Lead

 

Bracket

Snubber

3/8-16 Hex Nut

 

 

 

Rectifer Mounting

Insulator

 

 

 

Insulator

 

Heat Sink

 

Bracket

 

3/8-16 x 1 Cap Screw

 

 

 

 

 

 

 

 

 

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Fig. 18 ‘A’

 

Fig. 18 ‘B’

 

 

 

OUTPUT

A

 

 

 

 

 

 

 

SNUBBER

 

 

A

SECONDARY

CONNECTION

A

A

 

 

LEAD CONNECTION

A

 

A

 

A

 

 

 

(6 PLACES)

 

 

 

 

MOUNTING

 

 

 

 

BOLTS (4)

 

 

 

 

 

A

 

A

 

 

A

 

 

 

A

 

A

215

 

 

 

 

210

A

 

 

 

A

 

 

 

 

OUTPUT

 

A

 

 

 

 

 

 

SHUNT

 

 

 

 

CONNECTION

 

 

 

STRAP

 

 

 

 

A

 

 

 

Plain Washers (2)

Fig 18 ‘C’

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REPLACEMENT PROCEDURE

NOTE: Any instructions packaged with the replace- ment SCR Bridge assembly will supercede these instructions.

1.Use steel wool or Scotch-Brite to provide a bright, clean,smooth paint-free surface for connection of the leads. Clean the surfaces of the heat sink as well as those of the leads. Wipe away any abrasive material with a clean cloth.

2.Apply a thin coating of joint compound (provided with new assembly)to all of the heatsink areas where leads will be connected.

3.Carefully mount the SCR assembly into the DC- 600 using the original hardware or the hardware provided with the new assembly. See Figure F.18’A’.

NOTE: A new rectifier assembly will have mounting brackets with both 1/2” holes and 3/8” holes to allow for proper mounting in all units. The spare insulating tubes and washers are for use in older machines.

4.Reconnect the transformer secondary and snubber ‘A’ leads to the assembly. See Figure F.18’B’.

5.Mount the Output Snubber to the left side bracket and connect the lead to the Choke. See Figure F.18’C’.

NOTE: Torque all bolts for the following minimum settings:

1/4”

bolts

6 ft/lbs.

5/16” bolts

11 ft/lbs.

3/8”

bolts

19

ft/lbs.

1/2”

bolts

45

ft/lbs.

6.Bolt the shunt to the Positive Output Stud connec- tion strap and connect the # 210 and #215 leads as they were on the original assembly.

NOTE: It is important that the current feedback leads(twisted pair) and the meter leads are connected across the shunt and the other 215 leads connected near the top of the shunt assembly. See Figure F.18.

DC-600

Image 83
Contents DC-600 ISAFETYi Can be dangerous SafetyElectric Shock can kill Fumes and GasesFor Electrically Powered equipmentSûreté Pour Soudage a L’Arc Précautions DE SûretéElectromagnetic Compatibility EMC Safety Master Table of Contents for ALL Sections Table of Contents Installation Section Technical Specifications DC-600 InstallationSelect Proper Location Safety PrecautionsElectric Shock can Kill Ground Connection Fuse and Wire SizesElectrical Input Connections Connection for Highest Rating Plate VOLTAGE, 50 or 60 HZ Reconnect ProcedureConnection for 440 Volts 50 or 60 HZ V 60HZ See Machine Rating Plate for Required Input Supply Voltage Connections Output ConnectionsELECTRODE, Work and #21 Lead Terminal Strip 2 T.S.2 Auxiliary Power Control ConnectionsTerminal Strip 1 T.S.1 DC-600 Table of Contents Operation Section Operation Safety PrecautionsRecommended Processes and Equipment Design Features AdvantagesGeneral Description Output Control Output Voltage Current Meanings of Graphical Symbols on Case FrontOFF Input Power Welding CapabilityControls and Settings Meaning of Graphical Symbol for Ground CON- NectionOVERLOAD, OVERCURRENT, and Fault Protection Auxiliary Power in MS-RECEPTACLEOperating Steps Remote Control of Machine OperationWelding Procedure Recommendations Remote NA-3 Automatic Wire FeederLN-7 and Other Constant Wire Feeders LN-8 or LN-9 SEMI-AUTOMATIC Wire FeederDC-600 Table of Contents Accessories Section Field Installed Options AccessoriesWire Feeders and Tractors Factory or Field Installed OptionsFigure C.2 MULTI-PROCESS Switch Cable Connections Accessories Table of Contents Maintenance Section Routine and Periodic Maintenance MaintenanceSafety Precautions Electric Shock can Kill 1TABLE of CONTENTS-THEORY of Operation Section E-1 Input Circuit and Main TRANS- Former Theory of OperationFiring Board Firing CIRCUIT, Control CIR- Cuit and RectificationRectification Thermal Protection SCR Operation DC-600 1TABLE of Contents Troubleshooting and Repair F-1 HOW to USE Troubleshooting Guide 2TROUBLESHOOTING and REPAIRF-2PC Board Troubleshooting Procedures Troubleshooting and RepairControl Feeder. See Protective Devices Check all three phase input Output Control J1,Pin2. See Wiring Diagram Wiring Diagram Materials Needed PC Board Troubleshooting GuideTest Description PC Board Troubleshooting Guide Figure F.2 Control Board LEDs Control BoardDC-600 Internal Trigger Circuit Test Internal Trigger Circuit Test Procedure75 76 Internal Trigger Circuit TestDC-600 Firing Board Test Firing Board Test Control Board Test Figure F.7 Control Board Control Board TestMain Transformer Voltage Test Figure F.8 Input Contactor and Reconnect Panel Main Transformer Voltage TestFigure F.9 Transformer Secondaries Main Transformer Voltage Test Control Transformer Test Control Transformer Test ProcedureInput Contactor Test Voltage Test Input Contactor TestSCR Bridge Test SCR Bridge Test Anode Cathode Remove Insulating PaintActive Test Scope Settings Maximum Output Setting no Load Minimum Output Setting no Load 35TROUBLESHOOTING and REPAIRF-35 2V/Div Volts DC-600 Input Contactor CR1 CLEANING/REPLACEMENT Contactor Replacement Procedure Input Contactor CLEANING/REPLACEMENT ProcedureCleaning Procedure SCR Rectifier Bridge Removal and Replacement Procedure SCR Rectifier Bridge 42TROUBLESHOOTING and REPAIRF-42Removal and Replacement Procedure Removal ProcedureInsulator Lock Washer Plain Washer Output Snubber Lead Replacement ProcedureDC-600 Main Transformer and Choke Removal and Replacement Main Transformer and Choke Removal and ReplacementRemoval Procedure Weld Maximum Open Circuit Voltages Input Idle Amps and WattsDC-600 Table of Contents Diagram Section Electrical Diagrams Wiring Diagram 230/460/575 Volt Machines G3506-1 Schematic Complete Machine G3575 Schematic Control PC Board G3408-1 Control PC Board Assembly G3409-1 Schematic Firing PC Board G3741-1