Lincoln Electric SVM 117-A service manual Wire Drive Motor, Feedback

Page 49

E-4

THEORY OF OPERATION

E-4

 

 

to Section TOC

to Master TOC

WIRE DRIVE MOTOR AND FEEDBACK

 

 

 

 

 

Return

Return

 

WIRE

GAS

 

 

 

SPEED

SOLENOID

 

 

ARC

 

 

 

WIRE

 

 

 

 

 

DRIVE

 

 

VOLTAGE

 

 

 

MOTOR

 

 

 

CONTROL BOARD

 

 

 

 

 

G

 

 

TACH

 

 

 

 

 

 

 

 

MAIN

A

 

 

 

 

LINE

T

 

GUN TRIGGER AND THUMB SWITCH

 

SWITCH

TRANSFORMER

E

 

 

 

S

 

 

 

 

 

 

 

 

 

 

 

 

I

 

 

FEEDBACK

 

 

 

G

 

 

 

 

 

N

 

 

 

TOC

TOC

 

A

 

 

 

 

L

 

 

 

RECONNECT

 

 

 

POSITIVE

Section

Master

 

 

 

 

 

 

 

 

TERMINAL

 

 

C

 

CHOKE

 

 

 

 

 

 

A

F

 

 

 

P

E

 

to

to

 

 

A

E

 

 

 

C

D

 

 

SCR

I

B

 

Return

Return

 

 

 

RECTIFIER

T

A

 

 

 

O

C

 

FAN

 

R

K

NEGATIVE

 

S

 

MOTORS

 

 

TERMINAL

 

 

 

 

 

 

 

 

 

 

 

 

 

SHUNT

 

Figure E.5 - Wire Drive Motor and Feedback.

TOC

TOC

WIRE DRIVE MOTOR AND

Section

Master

FEEDBACK

 

 

to

to

The wire drive motor is controlled by the control board.

A motor speed feedback signal is generated at the

Return

Return

motor tach and sent to the control board. The control

 

 

 

 

board compares this feedback signal with the com-

 

 

mands set forth by the Wire Speed Control poten-

 

 

tiometer and sends the appropriate armature voltage

 

 

to the wire drive motor. The drive motor speed is thus

 

 

controlled which in turn regulates the electrode wire

 

 

feed speed through the gun.

Section TOC

Master TOC

 

 

to

to

 

NOTE: Unshaded areas of Block Logic

 

Diagram are the subject of discussion

Return

Return

 

 

 

 

WIRE-MATIC 250

 

 

 

Image 49
Contents Safety Depends on You WIRE-MATICARC Welding can be hazardous SafetyCylinder may explode if damaged Iii Electric and MAG- Netic FieldsSûreté Pour Soudage a L’Arc Précautions DE SûretéWIRE-MATIC Table of Contents Table of Contents Installation Current Range Duty Cycle Amps Volts at Rated AmpsFuse Superlag Type 750C CopperSelect Proper Location Safety PrecautionsInput Connections StackingInput Power Connections and Ground Connections Fuse and Wire SizesConnect Shielding GAS Figure A.4 Input Air Supply Connections Reconnect ProcedureFigure A.5 Reconnect Diagram For 208/230/1/60 Machines Install the Work Clamp InstallationConnect Output Components GUN Liner and Contact Output Polarity ConnectionGUN and Cable Installation Wire Size Conversion PartsWIRE-MATIC Operation General Description Safety InstructionsWELDING, Cutting Unit Features Design Features AdvantagesPower Source Features Recommended Processes and EquipmentMachine Capability Wire Feeder FeaturesLimitations Duty Cycle Amps VoltsFigure B.1 Operator Controls Controls and SettingsProcedure for Changing Drive Roll Using the Wire Drive RollLoading the Wire Reel Feeding Electrode Proper Wire FeedingTo mount 10 to 30 lb. spools 8 and 12 diameter Operating Steps Setting Idle Roll PressureStarting the Welder Making a Weld WIRE-MATIC Accessories Installing the K607-1 Spool GUN Adapter KIT OPTIONS/ACCESSORIESK607-1 Spool GUN Adapter KIT Spool GUN Module Board InstallationReturn Return to Section TOC Spool GUN Connection BOX InstallationSpool GUN Preparation Spool GUN ConnectionMaking the Weld Making a Weld with the Spool GUN Adapter K607-1 InstalledTimer KIT K585-1 Aluminum Wire Sizes Steel Wire Sizes Part NumberDrive Roll Kits To Make Spot Plug WeldsMaintenance Perform the following daily Routine and Periodic MaintenanceMaintenance Cable Cleaning Contact TIP and GAS Nozzle InstallationDrive Rolls and Guide Tubes GUN Tubes and Nozzles DROP-IN Reel Spindle and ClipsFigure D.2 Liner maintenance Liner Removal ReplacementTo open up the handle GUN Handle DisassemblyDescription English Size Metric Size WIRE-MATIC Theory of Operation Transformer Input Line Voltage and MainFeedback Control Output RectificationFigure E.4 Constant Voltage Output Constant Voltage OutputFeedback Wire Drive MotorThermal Protection Figure E.6 SCR Operation SCR OperationWIRE-MATIC Troubleshooting & Repair Recommended Course of Action HOW to USE Troubleshooting GuideElectric Shock can kill PC Board Troubleshooting ProceduresBoard can be dam- aged by static electricity Main Transformer Rectifier Assembly Test To Section TOC Perform the SCR Rectifier Perform the Wire Drive Motor Trolyte in these capacitors is Liquid elecPerform the Output Rectifier Test Description Main Transformer TestMaterials Needed ON/OFF Power Switch will be hot during these tests Main Transformer Test Test ProcedureMain Transformer Test Static SCR Rectifier Assembly Test Leads Figure F.4 SCR 1 Test Points Active SCR Rectifier Assembly Test Leads SCR connections Figure F.7 SCR Tester CircuitWire Drive Motor and Tachometer Feedback Test Wire Drive Motor and Tachometer Feedback Test Test Procedure Test for Feedback Voltage to the Control Board Test for Supply Voltage to TachometerNormal Open Circuit Voltage Waveform Scope SettingsTypical Output Voltage Waveform Machine Loaded Machine Loaded to 250 Amps AT 26 VDC Scope SettingsMachine Loaded to 220 Amps AT 22 VDC Scope Settings Troubleshooting & Repair Typical SCR Gate Voltage Waveform Removal and Replacement Procedure Control PC Board Removal and ReplacementMaterials Needed Removal and REPLACE- Ment Procedure Wire Drive Assembly Removal and Replacement Figure F.11 Wire Drive Assembly Removal Wire Drive Assembly Removal and Replacement ProcedureSCR Output Rectifier Removal & Replacement Disconnection Heat Sink Lead Right side heat sink See Figure F.14Capacitor Bank Removal and Replacement Components Bank Removal ReplacementMain Transformer Removal and Replacement Power Switch FAN Motor and FAN Removal and Replacement Figure F.16 Fan Motor and Fan Removal Components FAN Motor and FAN Removal and Replacement ProcedureTroubleshooting & Repair Open Circuit Voltage Wire Speed RangeInput Volts/Hertz 230/60 375WIRE-MATIC Table of Contents Electrical Diagrams Section WIRE-MATIC Electrical Diagrams Spool GUN Option Wiring Diagram 208/230 Code To Section Available from Lincoln Control PC Board G2332 Layout