Lincoln Electric SP-250 service manual Machine Loaded to 220 Amps AT 22 VDC Scope Settings

Page 81

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

F-34	TROUBLESHOOTING & REPAIR	F-34
	TROUBLESHOOTING & REPAIR

ABNORMAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED

ONE OUTPUT SCR NOT FUNCTIONING

MACHINE LOADED TO 220 AMPS AT 22 VDC

SCOPE SETTINGS

This is NOT a typical DC output voltage
waveform. One output SCR is not function-	Volts/Div	.20 V/Div.
ing. Note the increased ripple content. One
SCR gate was disconnected to simulate an	Horizontal Sweep	.5 ms/Div.
open or non-functioning output SCR. Each
vertical division represents 20 volts and	Coupling	. . . . .DC.
each horizontal division represents 5 mil-
liseconds in time. The machine was loaded	Trigger	. .Internal.
with a resistance grid bank.
Note: Scope probes connected at machine
output terminals: (+) probe to electrode, (-)
probe to work.

IDEALARC SP-250

Image 81

Contents Idealarc SP-250 Safety Depends on YouIdealarc SP-250 ARC Welding can be hazardousCylinder may explode if damaged Iii Electric and MAG- Netic FieldsSûreté Pour Soudage a L’Arc Précautions DE SûretéTable of Contents Installation Depth Weight GUN HeightStorage Operating Select Proper Location Safety PrecautionsInput Connections StackingInput Power Connections Ground Connections Fuse and Wire SizesFigure A.3 Ground Connection For 230/460/575 Volt Models Connect Shielding GASSide Reconnect ProcedureReturn to Section TOC Install the Work Clamp GUN Liner & Contact TIP InstallationConnect Output Components Output Polarity ConnectionFigure A.9 European Style Connector GUN & Cable InstallationOperation Additional Safety Precautions Safety InstructionsGeneral Description Electric Shock can killOperational System includes the following featuresControls Recommended ProcessesUnit Features Design FeaturesWire Feeder Features Power Source FeaturesMachine Capability LimitationsDuty Amps Volts Cycle Figure B.1 SP-250 Control Panel Keys Controls and SettingsProcess WIRE/GAS KEY Arrow KEY Operation When Used withArrow KEY Operation When Used with Manual KEY Arrow KEY Operation When Used with Auto KEYArrow KEY Operation When Used with Stitch KEY Arrow KEY Operation When Used with Spot KEYLeft arrow keys Do not function Right arrow keys Do not functionStep Trigger Interlock Keys Figure B.5 Using the Toggle FunctionChanging RUN-IN Mode Codes 10001 and Above RUN-IN ModeMaking a Weld in Auto Mode Operating StepsUsing the 4-STEP Interlock Function in Auto Mode Making a Spot Weld in Auto ModeTo make an arc spot plug weld Using the Wire Drive Roll Using the GUN Thumb Switch Magnum SP-250 onlyMaking a Stitch Weld in Auto Mode Using the GUN Trigger SwitchTo mount 10 to 30 lb. spools 8 and 12 diameter Loading the Wire ReelFeeding Electrode Setting Idle Roll PressureAccessories Options / Accessories Spool GUN Adapter KIT InstallationSpool GUN Module Board Installation Figure C.2 Spool Gun Module Board Installation Spool GUN Connection BOX InstallationFigure C.5 Spool Gun Connect Spool GUN ConnectionFigure C.6 Spool Gun Connection Spool GUN Installation to OLD K531 KITMaintenance Routine and Periodic MaintenanceControl Board Choke Fan Assembly Main Transformer Theory of Operation Power Supply Operation Input Line Voltage and Main TransFormer Back Control Output Rectification and FeedFigure E.4 Constant Voltage Output Constant Voltage OutputFigure E.5 Wire Drive Motor and Feedback Wire Drive Motor and FeedbackThermal Protection Figure E.6 SCR Operation SCR OperationTroubleshooting & Repair Recommended Course of Action HOW to USE Troubleshooting GuideBoard can be dam- aged by static electricity PC Board Troubleshooting ProceduresOutput Problems Warn Troubleshooting & Repair Function Problems Troubleshooting & Repair Wire Feeding Problems Trolyte in these capacitors is Liquid elecToxic. Avoid contact with any Portion of your bodyTroubleshooting & Repair On Screen Error Message Message Explanation Explanation of Prompting and Error MessagesExplanation of Prompting and Error Messages CONT’D On Screen Error MessageXxxx Current Overload Reduce Output Press ANY KEY to Stop Message Main Transformer Test Test DescriptionMaterials Needed Main Transformer Test Test Procedure From Expected Lead Voltage Lead Plug Location#206 4J6 #208 16J6 #209 7J6 G1992 Code 9402 only Troubleshooting & Repair Static SCR Rectifier Assembly Test Leads Figure F.4 SCR 1 Test Points Active SCR Rectifier Assembly Test Leads Figure F.7 SCR Tester Circuit and SCR connections 25F-25 SP-250 Keypad Resistance TestFigure F.9 Plug J2 Test Points Figure F.8A Plug J2 Location on G2252 PC Control BoardTest Points KEY Pressed Maximum Allowable 27F-27Table F.1 SP-250 Keypad Resistance Tests Wire Drive Motor and Tachometer Feedback Test Figure F.10A Plug J5 Location on G2252 PC Control Board Wire Drive Motor and Tachometer Feedback Test Test ProcedurePull the gun trigger #206B 4J6 #515B 1J6 #555 2J6 #541 6J6 #539 3J6Test 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 Materials Needed Control PC Board Removal and ReplacementTroubleshooting & Repair Keypad Removal and Replacement Keypad Removal and Replacement Procedure Wire Drive Assembly Removal and Replacement Figure F.13 Wire Drive Assembly Removal Wire Drive Assembly Removal and Replacement Procedure43F-43 SCR Output Rectifier RemovalFigure F.14 Heat Sink lead discon- nection Capacitor Bank Removal and Replacement Capacitor Bank Removal and Replacement Procedure Main Transformer Removal and Replacement Power Switch FAN Motor and FAN Removal and Replacement Figure F.18 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 375Table of Contents Electrical Diagrams G1992 Control PC Board Identification X9 . . . . . .IC-CMOS,UNDERVOLT-SENSING,RESET,MCU Idealarc SP-250 Electrical Diagrams G2252 Control PC Board TOC OCI2,OCI3 Optocoupler Triac Driver Idealarc SP-250 Electrical Diagrams SP-250 230/460/575V Wiring Diagram Wiring Diagram for Code 9546Thumb Switch Wiring Diagram for Code 9723Improper Lincoln Electric. This information