Theory of operation, E-6 pipeliner® 200 – Lincoln Electric PIPELINER 200 User Manual
Page 68

THEORY OF OPERATION
E-6
E-6
PIPELINER® 200
ENGINE, MAIN GENERATOR ARMATURE
& FRAME AND DC EXCITER
EXCITATION (FLASHING)
The main generator armature and the exciter armature
are mechanically coupled to the engine. When the
engine is started and running, the residual magnetism
that is stored in the exciter pole pieces is induced upon
the exciter armature. This causes the exciter to “build-
up” and produce a DC output voltage. This DC is
applied, via the field rheostat control, to the main gen-
erator shunt field coils. The exciter output is also con-
nected to the 120VDC receptacle.
MAIN SHUNT, INTERPOLE & SERIES COILS
The generator armature rotates within the magnetic
field created by the shunt field windings. A DC voltage
is induced in the armature and is transferred, through
the armature commutator and brushes, to the series
and interpole coils. The interpole coils, which are con-
nected in series with the positive output terminal, are
located so as to counteract any magnetic influences
that could cause mechanical distortion in the rotating
armature. The series coils are designed to oppose or
“buck” the DC voltage that is generated in the arma-
ture.
ENGINE, MAIN GENERATOR ARMATURE, FRAME
& DC EXCITER
CURRENT RANGE SELECTOR
The selector switch acts as a course current adjust-
ment by allowing varying amounts of series windings to
be included in the welding current path. The series
coils and selector switch are connected in series with
the negative output terminal.
FINE CURRENT ADJUSTMENT
The field rheostat control functions as a fine output cur-
rent adjustment by controlling the current through the
shunt windings, thus controlling the amount of magnet-
ism created in the field windings. Open circuit weld
voltage can also be controlled by the field rheostat con-
trol.
FIGURE E.6 — GENERATOR & EXCITER
NEGATIVE
OUTPUT
TERMINAL
SWITCH
-
SELECTOR
90 Min.
Max
GENERATOR
ARMATURE
B
R
U
S
H
E
S
&
C
O
M
M
U
T
A
T
O
R
INTERPOLE
COILS
RESIDUAL
MAGNETISM
GENERATOR
FIELD CONTROL
SHUNT
FIELD
SERIES
FIELD
ARMATURE
EXCITER
DC
ARMATURE
SHAFT
_
+
SERIES
COILS
TO
ENGINE
CONTROL/PROTECTION
MODULE
POSITIVE
OUTPUT
TERMINAL
+
SHUNT
FIELD
COILS
15 AMP
FUSE
RECEPTACLE
120VDC
MECHANICAL
COUPLING
+
-
Current
Sensing
P.C. Board