Lincoln Electric SVM186-A service manual Figure F.6 SCR Gate Locations

Page 67

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F-27

TROUBLESHOOTING AND REPAIR

F-27

 

 

ACTIVE SCR TEST (continued)

FIGURE F.6 – SCR GATE LOCATIONS

 

SCR2 CATHODE

SCR1 ANODE

SCR3 CATHODE

 

SCR4 ANODE

SCR1 CATHODE/SCR2 ANODE

SCR3 ANODE/SCR4 CATHODE

PLUG J7

34

SCR3 SCR4

SCR1

SCR2

 

2

1

S24018-4 (INSERTION SIDE)

SCR GATE LEADS/TEST POINTS

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TEST PROCEDURE (continued)

6.Connect SCR into the test circuit as shown (A) lead to anode (C) lead to cathode and (G) lead to the gate.

7.Close switch SW-1 (switch SW-2 should open), voltmeter should read zero. If the voltmeter reads higher than zero the SCR is shorted.

8.With switch SW-1 closed, close switch SW-2 for two seconds and release. The voltmeter should read 3 to 6 volts before and after switch SW-2 is released. If the voltmeter does not read, or reads only while SW-2 is depressed, the SCR or battery is defective (repeat Battery Test Procedure above).

9.Open switch SW-1, disconnect the gate lead (G) and reverse the (A) and (C) leads on the SCR. Close switch SW-1. The voltmeter should read

zero. If the voltage is higher than zero, the SCR is shorted.

10.Replace SCR Bridge Assembly if any SCRs do not pass the test in Step #3. See SCR

Bridge Assembly Removal and Replacement.

11.Replace plug J2 into the control board.

12.Replace the case wrap-around cover.

PRECISION TIG® 225

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Contents Precision TIG ISAFETYi Fumes and Gases SafetyFor Electrically Powered equipmentSûreté Pour Soudage a LʼArc Précautions DE SûretéElectromagnetic Compatibility EMC Safety Master Table of Contents for ALL Sections Table of Contents Installation Section Input Single Phase only InstallationK2533-2 Input at Rated Output Model Height Width Depth WeightTilting Safety PrecautionsSelect Suitable Location Mounting Lifting and MovingInput and Grounding Connections Return Section TOC Input Reconnect ProcedureConnections for Stick Smaw Welding Connections for TIG Gtaw WeldingPrecision TIG Table of Contents Operation Section Operation Recommended Processes and EQUIP- Ment Product DescriptionControl Functionality Figure B.1 Control PanelPOWER-UP Sequence Machine Rating Plate Case Rear ComponentsOperating Steps Welding in TIG ModePulse TIG Control Operation Turn the power switch to on Welding in Stick ModePrecision TIG Table of Contents Accessories Section Standard Equipment Packages AccessoriesTable C.1 Table C.2 Factory Installed OptionsK2348-1 Under-Storage Cart Field Installed OptionsTable of Contents Maintenance Section Spark GAP Adjustment MaintenanceSafety Precautions Routine and Periodic Maintenance1TABLE of CONTENTS-THEORY of Operation Section E-1 Theory of Operation Input Power CircuitGeneral Description Protected Output Rectification Feedback ControlFigure E.2 High Voltage/High Frequency Circuit High Voltage / High Frequency CircuitFigure E.5 DC Welding Current Generation DC Welding OutputFigure E.6 AC Square Wave Welding Current Generation AC Welding OutputFigure E.7 SCR Operation SCR OperationVAC Receptacle Protective CircuitsThermal Protection Overload Protection1TABLE of Contents Troubleshooting and Repair F-1 HOW to USE Troubleshooting Guide Troubleshooting and RepairWorkstations PC Board Troubleshooting ProceduresPerform the T1 Transformer Amptrol is depressed Troubleshooting and Repair Perform the SCR Bridge Test Possible Areas Misadjustments Problems SymptomsRecommended Course of Action Troubleshooting and Repair Troubleshooting and Repair Problems Symptoms Electric Shock can Perform the SCR Bridge Test Stick electrode Blasts Off when Weld current may be set too Test Description High Frequency Circuit Disable ProcedureMaterials Needed Figure F.1 Spark GAP Assembly ProcedureT1 Transformer Test T1 Transformer Test Primary Windings Primary Voltages Precision TIG Static SCR Test Precision TIG 225 Control Test ProcedureCase Cover Removal and Replacement Procedure Precision TIG Active SCR Test Active SCR Test Figure F.6 SCR Gate Locations Precision TIG Scope Settings Normal Open Circuit Voltage Waveform AC TIG ModeNormal Open Circuit Voltage Waveform DC TIG Mode Normal Open Circuit Voltage Waveform AC Stick Mode Normal Open Circuit Voltage Waveform DC Stick Mode Typical Output Voltage Waveform Machine Loaded AC TIG ModeMachine Loaded to 180 Amps AT 16VDC DC TIG Mode Machine Loaded to 180 Amps AT 26VDC AC Stick ModeDC Stick Mode Troubleshooting and Repair Precision TIG SCR Bridge Assembly Removal and Replacement Procedure Figure F.7 Case Back Mounting Screws SCR Bridge AssemblyProcedure Plug J2 Removed Replacement Procedure Precision TIG Polarity Switch Removal and Replacement Procedure Removal Procedure Polarity SwitchReplacement Procedure Precision TIG High Voltage Transformer Removal and Replacement Procedure Transformer Secondary Leads High Voltage TransformerFigure F.12 High Voltage Transformer Mounting Insulators Precision TIG 53F-53 Perform the SCR Bridge Assembly Replacement Procedure Input Idle Amps Retest After RepairRecommended Meters for Machine Output Tests Precision TIG Table of Contents Diagram Section Electrical Diagrams Schematic Complete Machine ALL Codes G5647 Schematic Control PC Board #1 G5640 Schematic Control PC Board #2 G5640 Schematic Control PC Board #3 G5640 PC Board Assembly Control #1 G5641 PC Board Assembly Control #2 G5641 1B0-S22530 PC Board Assembly Bypass L10121

SVM186-A specifications

The Lincoln Electric SVM186-A is a versatile and highly efficient welding machine that stands out in the competitive landscape of industrial welding equipment. Designed to meet the needs of both professionals and hobbyists, this machine combines advanced technology with robust construction, delivering outstanding performance in various welding applications.

One of the standout features of the SVM186-A is its multi-process capability. This welding machine can handle MIG, TIG, and Stick welding processes, making it suitable for a diverse range of projects, from light fabrication to heavy-duty work. This flexibility reduces the need for multiple machines, saving time and space for users who require versatility in their welding operations.

The SVM186-A is powered by a reliable and durable inverter technology, which ensures a stable arc and efficient operation across different materials, including stainless steel, aluminum, and mild steel. This inverter technology not only enhances performance but also reduces energy consumption, making it an environmentally friendly choice.

Another notable characteristic of the SVM186-A is its user-friendly interface. The digital display provides real-time information on voltage and wire feed speed, allowing welders to easily adjust settings for optimal results. This intuitive control panel design makes it accessible for both novice welders and seasoned professionals who value precision.

The machine is also built with safety features in mind. It comes equipped with overcurrent protection and thermal overload protection to prevent damage during operation. This ensures that users can work confidently, knowing that the equipment is designed to handle demanding tasks while prioritizing safety.

Portability is another advantage of the SVM186-A. Weighing in at a relatively light weight compared to other industrial welders, this machine is designed for ease of transport. Whether working on-site or in a workshop, welders can easily move the equipment as needed.

In summary, the Lincoln Electric SVM186-A is a sophisticated welding machine that merges technology and practicality. Its multi-process capability, inverter technology, user-friendly interface, safety features, and portability make it a top choice for those seeking dependable and efficient welding solutions. Whether for professional fabrication or personal projects, the SVM186-A is equipped to handle the demands of modern welding tasks with exceptional ease and effectiveness.
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