Residual Voltage Check - Westerbeke 5.0Kw BCDR Operator's Manual

7.6KW BT GENERATOR SINGLE PHASE
INTERNAL WIRING FOR
12 SIDD BT GENERATOR
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WHT/ BlK •
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ORANGE
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AC
BLACK
DC
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AC
GREEN
YELLOW
RESIDUAL VOLTAGE CHECK
1.
"Residual Voltage 18 - 22 volts AC.
NOTE:
The
anwunt
of no-load voltage produced by the
generator can be an indicator of where in the generator
the problemlfault may lie.
1bis voltage is the AC voltage produced by the generator
from magnetism in the exciter stator field. 1bis voltage is
measured between the AC neutral and hot leges) with no-
load on the generator running at its hertz.
The presence of residual voltage is an indication that the
following generator components are OK:
1. Exciter Rotor (B-1 a, b, & c) & (B-2)
2. Rotating Field (B-3)
3. Main Stator (C-1"& C-2)
4. Compound Transformer (D-1 & D-2)
The fault lies in one or more of the following compo-
nents in the exciter circuit:
A. Exciter Stator (A-I)
B. Bridge Rectifier (G)
C. Main Stator Auxiliary Windings (C-3)
D. Compound Transformer Auxiliary Winding (D-3)
2. 1Welve (12) volts DC excitation of the exciter stator
windings should cause the generator to produce between
125 - 135 volts AC between each hot lead and the neu-
tral. (1\velve volts DC is applied between the lifted (+)
and (-) leads of the bridge rectifier,
+
to
+
and - to -.)
Correct voltage produced with twelve volts DC excitation
indicates the fault is in one or more of the above listed
~omponents·B,·-D-or
E. If·the generator doosnot proouce
125 - 135 volts AC, then include A and C. .
3. The absence of any voltage from the generator indicates a
fault with the main stator windings C-1 and C-2 and/or
the compound transformer windings D-1 and D-2. Other
failed components that
can
produce this same no-voltage
output are the posi-resistor in the exciter rotor and four or
more failed diodes in the exciter rotor.
~
~
" , _ WHT/GREEN •
S
o
I T
L-.. _ _ ....
U
D
a.
Apply 12 volt DC excitation to the exciter stator wind-
ings as explained in paragraph 2. A fault in the main
stator and/or compound transformer windings such as a
short will cause the generator engine to load down and
the shorted windings to eventually produce smoke as
the excitation is continued.
4. Voltage output greater than residual and less than the
rated output indicates a fault in the exciter rotor/field B-1,
B-2, B-3. Excitation of the generator as explained in
paragraph 2 should produce a partial rise in voltage out-
put and, when removed, the voltage will return to the
original low output
JUMPER
. FROM DC(-)
START MOTOR
I
SOLENOID
I'
.
/
/
I
," .. .j
::' 1 -
--,
POSITIVE (+)
ORANGE
I'
BRIDGE
RECTIFIER
EXCITING mE GENERATOR
WITH 12 VOLTS
KEEP THE EXCITER CIRCUIT
POLARITY CORRECT:
DC+ to Battery at Starter
DC- to Case Ground
NOTE:
Current model bridge
rectifiers are configured
differently, but
+
and -
are
still located at the comers.
Engines & Generators
41