E-6

THEORY OF OPERATION

E-6

 

FIGURE E.2 - GENERAL DESCRIPTION

 

Return to Master TOC

Master TOC

THERMOSTART

BUTTON

TO IDLE / ENGINE

PROTECTION BOARD

TO IDLE/ENGINE

PROT. BOARD

S

T

A

R

STARTER T

SOLENOID E

R

RUN/STOP

IDLE SWITCH

SWITCH

 

THERMOSTAT

INJECTION

PUMP

SOLENOID

SYSTEM

DIESEL

ENGINE

OIL

PRESSURE TEMP

SWITCH SWITCH

IDLE

SOLENOID

ELECTRODE

TERMINAL

OUTPUT

CONTROL

MIN

MAX

(OFF)

 

AC

 

 

 

 

 

(-)

(+)

 

 

 

 

AC

 

 

 

 

 

 

REMOTE

 

 

 

 

 

RHEOSTAT

LOCAL

 

 

 

 

 

 

 

 

 

POLARITY

RHEOSTAT

 

 

 

 

(JOB SELECTOR)

 

 

 

 

SWITCH

 

 

 

 

RESISTOR

 

 

 

FLASHING

TO HOUR METER

 

(+)

 

RESISTOR AND

 

 

 

 

 

SHUNT COILS

 

 

 

DIODE

 

 

(-)

 

 

 

 

 

 

 

 

SERIES COILS

 

EXCITER

 

 

 

 

 

 

 

 

 

 

WINDING

(-)

(+)

 

GENERATOR

 

 

 

 

EXCITER

 

 

 

ARMATURE

 

ROTOR

 

 

 

AUXILIARY

POWER

WINDINGS

INTERPOLE COILS

115 VAC

230 VAC

to

 

HOUR

IDLE / ENGINE

AMMETER

METER

PROTECTION BOARD

RECEPTACLES

RECEPTACLES

 

 

 

 

 

TO

 

WORK

 

 

TERMINAL

 

FLASHING

ENGINE

TO ALTERNATOR

START

RESISTOR

AND

FAULT

 

BUTTON

FLASH/SENSE

DIODE

LIGHT

 

 

 

TO INJECTION

 

 

 

PUMP SOLENOID

WELDING GENERATOR OPERA-

TION

Return to Section TOC

Return to Section TOC

Return to Section TOC

Section TOC

Return to Master TOC

Master TOC

Overview:

The welding generator is coupled directly to the engine and produces the DC current required for welding and arc gouging. The welding power is induced in the wind- ings of the armature when it spins in a magnetic field. The power produced in the armature is converted to direct current (DC) by a commutator and a set of car- bon brushes, which are then connected to the interpole coils, the series coils, and the reactor assembly. The weld current is controlled by varying the field (Job Selector) and the reactor (Current Control) setting, using the front panel control knobs.

Excitation and field control:

Before any welding current can be produced, there must be a magnetic field in which the armature can spin. Creating this magnetic field is often described as exciting the generator, and is accomplished by passing controlled DC current through two shunt coils in the generator stator.

The power used to excite the generator starts out as AC current produced by the exciter/auxiliary alternator. This AC current passes through a remote/local switch and then through either a remote or the front panel mounted 64 Ohm rheostat. The now controlled AC current is then converted to direct current (DC) by a full wave bridge rectifier. The DC output from the rectifier then passes through a polarity reversing switch, and is then applied to the two series connected shunt coils in the generator stator.

Reversing the polarity of the field also reverses the polarity of the weld current. When the polarity switch is moved to the neutral position, the shunt coils are dis- connected. The resulting collapse of the magnetic field around these coils can produce a very high induced voltage. A 500 Ohm resistor is connected in parallel with the shunt coil set to reduce this voltage to a level that is within the limits of the insulation used. It also helps reduce arcing and damage to the polarity switch.

Return to

Return to

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

SAE-400 SEVERE DUTY

Page 36
Image 36
Lincoln Electric SVM187-A service manual Overview, Excitation and field control

SVM187-A specifications

The Lincoln Electric SVM187-A is a cutting-edge welding machine designed for professional welders and industrial applications. Known for its reliability and performance, it stands out in the competitive welding equipment market. This versatile machine is structured to handle various welding processes, making it a popular choice among users.

One of the primary features of the SVM187-A is its multifunctional capabilities. It supports MIG, TIG, and Stick welding, allowing users to switch between different welding techniques seamlessly. This flexibility makes it suitable for diverse applications, whether working on automotive repairs, metal fabrication, or construction projects. Additionally, the machine is equipped with a robust power output, ranging from low to high amperage settings, enabling users to tackle a wide array of materials, including mild steel, stainless steel, and aluminum.

The SVM187-A incorporates advanced inverter technology, which ensures increased efficiency and reduced energy consumption. This technology leads to a more compact design, making the unit portable and easy to transport. The lightweight construction of the machine does not compromise its durability; it is built with high-quality materials to withstand the rigors of a professional workshop.

Another notable characteristic of the SVM187-A is its user-friendly interface. The intuitive control panel includes digital displays for precise settings adjustments, ensuring accuracy during operation. Beginners and seasoned welders alike can benefit from the clear and straightforward design, reducing training time and enhancing productivity.

Safety features are paramount in the SVM187-A's design. The machine is equipped with thermal overload protection, ensuring that it operates within a safe temperature range to prevent damage and promote longevity. Additionally, it features automatic voltage regulation, which maintains a stable arc even under varying input voltage conditions.

In summary, the Lincoln Electric SVM187-A is a versatile, efficient, and user-friendly welding machine suited for both professional and industrial applications. Its multifunctionality, inverter technology, and robust safety features set it apart from competitors, making it a reliable choice for welders seeking to elevate their craftsmanship while ensuring safety and efficiency. This machine represents the innovation and quality that Lincoln Electric is renowned for in the welding industry.