Theory of operation, General description – Lincoln Electric MULTI-SOURCE SVM155-A User Manual

Page 24

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GENERAL DESCRIPTION

The Multi-Source is designed to supply power to the
Multi-Weld Arc Converter welders. The Multi-Source
is an SCR controlled constant voltage (CV) DC power
supply that can operate with a wide range of three
phase input voltages. The machine's peak output
voltage helps regulate against wide variations in out-
put loading and/or variations in input line voltages.
This ability provides for a consistently high stable volt-
age applied to the Multi-Welds so as to provide good
manual electrode welding capability.

INPUT VOLTAGE, FILTER, CONTAC-
TOR AND CONTROL TRANS-
FORMER

The desired three phase power is connected to the
Multi-Source via a reconnect panel located in the input
box at the rear of the machine. The reconnect panel
allows the user to configure the machine for the
desired input voltage. The three phase input power is
also applied to a filter assembly that is located in the
input box. Two phases of the input voltage are applied
to the T2 control transformer. The control transformer

has a single primary-to-secondary ratio (no taps) that
spans the full input range up to 600VAC. The sec-
ondary voltage developed on the secondary of the
control transformer is applied to the control box full
wave bridge rectifier via a thermostat and the input
power switch. The input contactor , which is activat-
ed and controlled by the control board, applies the
three phase AC input voltage to the primary windings
of the T1 main transformer.

THEORY OF OPERATION

E-2

MULTI-SOURCE