Lincoln Electric SVM 122-A Theory of Operation, Input Line Voltage, Contactor and Main

Page 41

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E-2

E-2

THEORY OF OPERATION

FIGURE E.2 – INPUT LINE VOLTAGE, CONTACTOR AND MAIN TRANSFORMER

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CONTROL

TRANSFORMER

POWER

 

 

 

SWITCH

 

 

MAIN

 

 

 

 

 

TRANSFORMER

 

 

R

 

 

 

E

 

 

 

C

 

 

 

O

 

 

 

N

 

 

 

N

 

 

 

E

 

 

 

C

 

 

 

T

 

INPUT

 

 

 

CONTACTOR

 

 

 

 

 

T

115VAC

 

REMOTE

E

S

TO

CONTROL

R

T

CONTROL

 

M

R

BOARD

 

I

I

 

 

N

 

 

P

 

 

A

 

 

L

 

 

 

 

FAN

 

 

 

42VAC

 

 

14 PIN

 

 

AMPHENOL

OUTPUT

ARC FORCE

 

 

 

CONTROL

CONTROL

 

 

 

 

PART OF

 

 

 

 

MODE

 

 

 

 

SWITCH

 

 

 

 

 

 

FEEDBACK

 

CONTROL BOARD

 

 

NEGATIVE

 

 

 

 

OUTPUT

G

S

 

PART

TERMINAL

 

 

A

I

 

OF

 

T

G

 

MODE

 

 

SWITCH

 

E

N

 

 

 

 

 

 

A

 

 

 

 

L

 

 

 

 

S

 

 

OUTPUT

 

 

 

 

 

 

 

 

CHOKE

 

 

F

 

 

 

PART

E

 

 

 

OF

E

 

 

 

MODE

D

 

 

 

SWITCH

B

START

 

 

 

A

BOARD

 

 

 

C

 

 

 

 

 

 

OUTPUT

K

 

 

 

 

 

 

 

CAPACITORS

 

 

 

 

 

 

 

POSITIVE

 

 

 

 

OUTPUT

 

 

 

 

TERMINAL

SCR / DIODE

SHUNT

REED

 

SWITCH

 

 

 

HYBRID BRIDGE

 

 

 

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GENERAL DESCRIPTION

The DC-400 is a multiprocess welder power source

The transformer changes the high voltage, low current

capable of both constant voltage and constant current

input power to a lower voltage, higher current output.

operation. Its power system is SCR controlled with

The finishes or “neutrals” of the main secondary coils

solid state electronic circuitry. Minimum to maximum

are connected together, and the three starts of the

output is obtained with a single potentiometer control.

secondary windings are connected to the rectifier

INPUT LINE VOLTAGE,

bridge assembly. In addition, the main transformer has

separate and isolated 115VAC and 42VAC auxiliary

CONTACTOR AND MAIN

windings. The 115VAC winding supplies power to the

TRANSFORMER

cooling fan and also offers 10 amps of auxiliary power,

at the terminal strip and 14 pin amphenol, to operate

 

The desired three-phase input power is connected to

wire feeding equipment. The 42VAC auxiliary power is

the DC-400 through an input contactor, located in the

available at the 14 pin amphenol only and is protected

input box at the rear of the machine. Two phases of

by a 10 amp circuit breaker. The three 21VAC phase

the input line are also connected to the control trans-

angle windings are also housed in the main trans-

former, which, through the power switch, supplies

former assembly. These windings provide power and

power to activate the input contactor.

“timing” for the control board.

A reconnect panel allows the user to configure the machine for the desired input voltage. This AC input voltage is applied to the primary of the main trans- former.

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

IDEALARC DC-400

LINCOLN ®

ELECTRIC

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Contents Idealarc TMDC-400 Safety Depends on YouCalifornia Proposition 65 Warnings SafetyElectric Shock can kill Cylinder may explode if damaged Précautions DE Sûreté Master Table of Contents for ALL Sections Table of Contents Installation Section Technical Specifications Idealarc DC-400 InstallationSelect Suitable Location Safety PrecautionsLifting TiltingGround Connection Input ConnectionsInput Supply Connections Electric Shock can killFigure A.3 Input Power Supply Connections Input Wire and Fuse SizeInput Supply Connection Diagram Reconnect ProcedureFigure A.6 Output Terminal Connections Output ConnectionsCycle Wire Feeder ConnectionsCycle 500 Amp 50% Duty Operation Section Operating Instructions Safety InstructionsOPERATIONB-2 General Description OperationFigure B.1 Case Front Controls Controls and SettingsOperation Welding Procedure Recommendations Remote ControlWelding Operation Operating StepsARC Striking with the NA-3 Start Board NA-3 Automatic Wire FeederLN-8 Semiautomatic Wire Feeder NA-5 Automative Wire FeederOverload Protection Auxiliary PowerTable of Contents Accessories Factory Installed Option OPTIONS/ACCESSORIESField Installed Options Diode OptionConnections Multiprocess Switch OperationK843 Amptrol Adapter Installation Instructions Remote Control Adapter Cable K864Remote Output Control K857 with K864 Adapter Plug or K775 Amptrol Adapter Cable K843Amptrol and Hi-Freq. Kit The Amptrol will start K843 Amptrol Adapter Installation InstructionsConnecting the NA-3 to the Idealarc DC-400 Terminal Strip Automatic Wire FeedersCapacitor Discharge Circuit K828-1 HI-FREQ KIT K799 for Codes 8634 and Above onlyConnecting the NA-5 to the Idealarc DC-400 Terminal Strip To NA-3 or NA-5 Input Cable Plug K597-XX Input Cable Assembly Idealarc DC-400Connecting the LN-7 to the Idealarc DC-400 14-PIN Amphenol Semiautomatic Wire FeedersConnecting the LN-7 to the Idealarc DC-400 Terminal Strip Accessories Accessories Figure C.11 Idealarc DC-400/LN-742 Connection Diagram Table of Contents Maintenance Routine and Periodic Maintenance Figure D.1 General Component Locations Table of Contents Theory of Operation Section Input Line Voltage Theory of OperationContactor and Main TransformerOutput Mode and CONTROL, Rectification and Feedback Protective Devices and Circuits Figure E.4 SCR Operation SCR OperationTable of Contents Troubleshooting & Repair Section HOW to USE Troubleshooting Guide Troubleshooting & RepairPC Board can be damaged by static electricity PC Board Troubleshooting ProceduresOutput Problems Troubleshooting GuidePerform the Main Transformer Rectifier Bridge Test Tifier Bridge Test Output Problems Test Perform the SCR/Diode Rec Tifier Bridge Test Function Problems Form the SCR/Diode Rectifier Welding Problems Toxic. Avoid contact with any Portion of your body. CleanTrolyte in these capacitors is Make sure welding process is Materials Needed Input Contactor TestDescription Input Contactor Test Test ProcedureFigure F.2 Input Contactor Test Connections Test for Contact ContinuityControl Transformer T2 Voltage Test Figure F.3 Control Transformer and Lead Locations Control Transformer T2 Voltage TestTroubleshooting & Repair Main Transformer T1 Voltage Test Main Transformer T1 Voltage Test Figure F.6 Main Secondary Lead Test Points Troubleshooting & Repair Figure F.8 Control Board Plug P1 Location Plug P1 Phase Angle Winding VoltagesStatic SCR/DIODE Rectifier Bridge Test Figure F.9 Control Board and Snubber Board Plug Locations Static SCR/DIODE Rectifier Bridge TestSCR Test Active SCR Test P1 and P3 Locations Plug P5 Location Active SCR TestFigure F.15 Heat Sink Test Points Figure F.16 SCR Tester Circuit and SCR Connections CH1 Scope SettingsMaximum Output Setting no Load Troubleshooting & Repair Troubleshooting & Repair Troubleshooting & Repair 2V/Div Troubleshooting & Repair Input Contactor CR1 CLEANING/REPLACEMENT Contactor Replacement Procedure Input Contactor CR1 CLEANING/REPLACEMENTCleaning Procedure FAN Motor and Blade Removal and Replacement Procedure FAN Motor and Blade Removal and ReplacementSCR/DIODE Rectifier Assembly Removal and Replacement Removal and Replacement SCR/DIODE Rectificer AssemblySCR Removal and Replacement Special Instructions SCR Removal and ReplacementFigure F.21 1/2 Wide Leaf Spring Procedure for the 1/2 Inch Wide SpringClamping Procedure For 1/4-20 CAP Screws Clamping Procedure For 1/4-28 CAP ScrewsInch Wide Spring Procedure forAfter Replacing the SCRs Mounting of Stud Type Diodes to Aluminum Heat Sinks Diode Stud Foot Inch Size Pounds Mounting of Stud Type Diodes to AluminumHeat Sinks Main Transformer Removal and Replacement Removal of Lift Bail Main Transformer Removal & ReplacementFigure F.26 Choke Removal Removal of Choke and TOP Iron AssemblyFigure F.27 Epoxy MIX Application Areas Reassembly of Transformer CoilsFigure F.28 Coil Lead Placement Figure F.30 Primary Thermostat Location Reassemble the Lift Bail Reassembling the Main Transformer Into the MachineMode Input Hertz Open Circuit Volts Input volts/Phase/Hertz Maximum Idle Amps Maximum Idle KWRetest After Repair Input Idle Amps and WattsRetest After Repair Maximum Acceptable Output Voltage AT Minimum Ouput SettingsMode Control Settings Load Table of Contents Electrical Diagrams Section Idealarc DC400 LOW Voltage Wiring Diagram Codes 9847Only. It may not be accurate for all Wiring Diagram CodeControl DC400 Control PC Board G2588 LayoutTP2 Starting PC Board M14520 LayoutSnubber PC Board M15370 Layout 2586 Control PC Board G2588 SchematicGeneral Information Starting PC Board M14520 SchematicGeneral Information Snubber PC Board M15370 Schematic
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