Lincoln Electric SVM186-A Theory of Operation, General Description, Input Power Circuit

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TOC

TOC

E-2E-2

THEORY OF OPERATION

FIGURE E.2 - General Description & Input Power Circuit

BY-PASS

BOARD

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TOC

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TOC

INPUT

POWER

SWITCH BYPASS

ASBLY

H1

H2

H3

115 VAC

FAN

Receptacle

 

Circuit Breaker

Protected

 

MAIN

TRANSFORMER

X1

X2

18VAC

18VAC

115VAC

POLARITY

SWITCH

AC DC+

SCR

BRIDGE

SHUNT AC DC-

F

E

E

D

B

A

C

K

CONTROL

BOARD

WORK

ELECTRODE

HI-FREQUENCY

TRANSFORMER

C

H

O

K

E

HIGH VOLTAGE

TRANSFORMER

CIRCUIT

115VAC

POWER "ON"

DIGITAL DISPLAY

MODE

SWITCH

Return to Section

REMOTE

 

 

THERMO-

RECEPTACLE

THERMAL

GAS

 

STATS

 

LIGHT

VALVE

 

 

OUTPUT CONTROL

AUTO

PULSE TIG

STICK

AC

PULSE POSTFLOW

BALANCE FREQ. LED

LED

BALANCE

CONTROL CONTROL

LED

LED

 

CONTROL

 

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Section TOC

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Master TOC

GENERAL DESCRIPTION

The PRECISION TIG® 225 is a member of our field acclaimed PRECISION TIG® family of industrial arc welding power sources. Premium features include:

1.Precise constant current output.

2.Full range square wave AC/DC TIG (GTAW) welding.

3.Enhanced version of the patented MicroStartTM Technology for its lower Minimum (5amps) to high- er Maximum (225 amps) output control range.

4.Built-in high frequency stabilization for DC TIG starting and continuous AC TIG welding.

5.AC/DC Stick (SMAW capability.)

INPUT POWER CIRCUIT

The desired single-phase input power is connected to the TIG 225 through an input power switch located in the front panel of the machine. The machine can be configured for either 230VAC or 208VAC input voltage by connecting the appropriate lead (H2 or H3) to the input power switch. When the input power switch is turned “ON” the input voltage is applied directly to the primary of the main transformer.

The main transformer changes the high voltage, low current input power to a low voltage, high current out- put which is available at the main secondary winding (X1 and X2). In addition three auxiliary windings are incorporated in the main transformer. The 115VAC winding supplies power to the fan motor, the 115 VAC receptacle, and also, through the control board, pow- ers the gas solenoid valve and the high voltage trans- former. The 18VAC winding provides power to the trig- ger circuitry. The other 18VAC winding is rectified and regulated to a 15VDC supply which operates the cir- cuitry on the control board.

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

PRECISION TIG® 225

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Contents Precision TIG ISAFETYi Safety Fumes and GasesPowered equipment For ElectricallyPrécautions DE Sûreté Sûreté Pour Soudage a LʼArcElectromagnetic Compatibility EMC Safety Master Table of Contents for ALL Sections Table of Contents Installation Section Installation Input Single Phase onlyModel Height Width Depth Weight K2533-2 Input at Rated OutputLifting and Moving Safety PrecautionsSelect Suitable Location Mounting TiltingInput and Grounding Connections Input Reconnect Procedure Return Section TOCConnections for TIG Gtaw Welding Connections for Stick Smaw WeldingPrecision TIG Table of Contents Operation Section Operation Product Description Recommended Processes and EQUIP- MentFigure B.1 Control Panel Control FunctionalityPOWER-UP Sequence Case Rear Components Machine Rating PlateOperating Steps Welding in TIG ModePulse TIG Control Operation Welding in Stick Mode Turn the power switch to onPrecision TIG Table of Contents Accessories Section Standard Equipment Packages AccessoriesTable C.1 Factory Installed Options Table C.2Field Installed Options K2348-1 Under-Storage CartTable of Contents Maintenance Section Routine and Periodic Maintenance MaintenanceSafety Precautions Spark GAP Adjustment1TABLE of CONTENTS-THEORY of Operation Section E-1 Theory of Operation Input Power CircuitGeneral Description Output Rectification Feedback Control ProtectedHigh Voltage / High Frequency Circuit Figure E.2 High Voltage/High Frequency CircuitDC Welding Output Figure E.5 DC Welding Current GenerationAC Welding Output Figure E.6 AC Square Wave Welding Current GenerationSCR Operation Figure E.7 SCR OperationOverload Protection Protective CircuitsThermal Protection VAC Receptacle1TABLE of Contents Troubleshooting and Repair F-1 Troubleshooting and Repair HOW to USE Troubleshooting GuidePC Board Troubleshooting Procedures WorkstationsPerform 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 Procedure Figure F.1 Spark GAP AssemblyT1 Transformer Test T1 Transformer Test Primary Windings Primary Voltages Precision TIG Static SCR Test Test Procedure Precision TIG 225 ControlCase Cover Removal and Replacement Procedure Precision TIG Active SCR Test Active SCR Test Figure F.6 SCR Gate Locations Precision TIG Normal Open Circuit Voltage Waveform AC TIG Mode Scope SettingsNormal 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 AC Stick Mode Machine Loaded to 180 Amps AT 26VDCDC Stick Mode Troubleshooting and Repair Precision TIG SCR Bridge Assembly Removal and Replacement Procedure SCR Bridge Assembly Figure F.7 Case Back Mounting ScrewsProcedure Plug J2 Removed Replacement Procedure Precision TIG Polarity Switch Removal and Replacement Procedure Polarity Switch Removal ProcedureReplacement Procedure Precision TIG High Voltage Transformer Removal and Replacement Procedure High Voltage Transformer Transformer Secondary LeadsFigure 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.