TOC

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E-3E-3

TROUBLESHOOTING & REPAIR

FIGURE E.3 – MAIN TRANSFORMER, CONTROL BOARD, COOLING FAN MOTOR, & LEDs

SURGE

NOISE

FILTER

INPUT

CONTACTOR

R E C O N N E C

T T2

CONTROL

TRANSFORMER

THERMOSTAT SWITCH

CONTROL

BOX

RECTIFIER

CONTACTOR

VAC 120

FAN VOLTAGE

T1

MAIN

TRANSFORMER

SCR OUTPUT RECTIFIER

 

 

 

SHUNT

 

 

 

TO CONTROL

 

 

 

BOARD

 

 

 

GATE SIGNALS

32 VAC

32 VAC

32 VAC

 

 

 

RESISTOR

FIRING

 

 

BANK

BOARD

WORK

TERMINAL

FILTER

CAPACITOR

LIMITING

RESISTOR

ELECTRODE

TERMINAL

TO CONTROL

BOARD

Return to

Return to

CONTROL

 

 

BOARD

 

CONTROL

FAN

THERMOSTAT

SIGNAL

G Y

W

 

DIGITAL

 

 

METER

LED LED LED

 

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MAIN TRANSFORMER, CONTROL BOARD, COOLING FAN MOTOR, DIGITAL METER AND INDICATOR LIGHTS (LEDs)

The main transformer changes the high voltage, low current input power to a lower voltage, higher current output. The finishes or "neutrals" of the main sec- ondary coils are connected together and the six starts of the secondary windings are connected to the SCR output rectifier assembly. In addition the main trans- former has an isolated 120VAC (nominal) winding the supplies 120VAC, via the control board, to operate the cooling fan motor. The three isolated 32VAC (nominal) phase angle windings are also housed in the main transformer assembly. These windings provide power and "timing" information to the firing board.

The control board receives a widely-varying DC volt- age from the control box rectifier. The switching power supplies, that are housed on the control board, supply DC current to the control circuits and the input contactor. The control board receives current feed- back information from the output shunt, voltage feed- back information from the output terminals and tem- perature information from several thermostats. This feedback information is processed by the control board. The control board then sends the appropriate gate firing signals to the firing board, output informa- tion to the digital meter and command signals to the

cooling fan motor and the input contactor.

The cooling fan is controlled by the control board. The F.A.N. (fan as needed) will be activated with an output current greater than 20 amps. It can also be activated (via the control board) by a thermostat located on the main transformer iron.

A current sensing circuit on the control board controls the digital meter display. This meter provides the user with an indication of the percentage of available power that is being drawn from the Multi-Source.

There are three indicator lights located on the front panel of the Multi-Source. The green safe output light indicates when the machine's output voltage is within the safe operating range. Other indicator lights include the amber thermal light that indicates the ther- mostat, located on the negative output lead, has opened due to an over temperature condition. The white power light indicates when the control board is energized.

MULTI-SOURCE

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Lincoln Electric SVM155-A service manual Troubleshooting & Repair, Return to Section Section TOC

SVM155-A specifications

The Lincoln Electric SVM155-A is a state-of-the-art welding machine that excels in versatility and performance, making it ideal for both professional welders and hobbyists. This multi-process welder supports MIG, TIG, and stick welding processes, allowing users to tackle a wide range of applications with a single device. Its user-friendly design and advanced technology make it an exceptional choice for those looking to enhance their welding capabilities.

One of the main features of the SVM155-A is its robust power output, which can handle welding materials ranging from thin sheets to heavier stock. The welder offers a high duty cycle, ensuring that users can work efficiently without the need for prolonged breaks. This is especially important in industrial settings where productivity is key. Additionally, the SVM155-A is equipped with a digital display that allows for easy monitoring and precise control of the welding parameters, ensuring consistency in weld quality.

The European-designed INVERTER technology embedded in the SVM155-A significantly contributes to its lightweight and compact design. Weighing in at only 19.4 lbs, this welder is portable and ideal for fieldwork or workshops where space is limited. The inverter technology not only reduces the size and weight but also improves energy efficiency, leading to lower operational costs over time.

The SVM155-A also features advanced safety mechanisms, including over-current protection to safeguard the machine from potential damage during excessive use. It also includes a thermal overload shut-off, which prevents overheating, ensuring a longer lifespan for the welder.

Another standout characteristic of the SVM155-A is its exceptional arc stability and ease of use. The machine is designed to provide a smooth and consistent arc, reducing spatter and ensuring clean welds. Moreover, the welder is compatible with a wide range of materials, including stainless steel, aluminum, and carbon steel, further enhancing its versatility.

In conclusion, the Lincoln Electric SVM155-A is a powerful, durable, and multifunctional welding machine that incorporates advanced technologies to meet the needs of modern welding applications. Its portability, safety features, and ability to deliver high-quality welds make it an excellent investment for anyone looking to improve their welding skills or expand their capabilities in various welding projects.