Westerbeke WPDS-20 Technical Manual page 96

T.59
GENERATOR TROUBLESHOOTING
PREPARATION
A few simple checks and a proper troubleshooting
procedure can locate the probable source of trouble
and cut down troubleshooting time.
1. Check all modifications, repairs, replacements
performed since last satisfactory operation of set
to be sure that connection of generator leads are
correct. A loose wire connection, overlooked
when installing a replacement part could cause
problems. An incorrect connection, an opened
circuit breaker, or a loose plug-in printed circuit
board are all potential malfunction areas to be
eliminated by a visual check.
2. Unless absolutely sure that panel instruments are
accurate, use portable test meters for
troubleshooting.
3. Visually inspect components on VR21. Look for
dirt, dust, or moisture and cracks in the printed
solder conductors. Burned resistors, arcing
tracks are all identifiable. Do not mark on printed
circuit boards with a pencil. Graphite lines are
conductive and can cause short circuits between
. components.
The question and answer troubleshooting guide
which follows, gives a step-by-step procedure for
-;hecking the generator components. Refer to Figure
22 for an electrical schematic of the generator and
voltage regulator connections.
TROUBLESHOOTING PROCEDURES
This troubleshooting information is divided into
tables, A, B, C, and D as follows:
A. No build up of AC output voltage.
B. AC output voltage builds up, but is unstable.
C. AC output voltage builds up, but is high or low.
F2-
BRUSHLESS
EXCITER
(39. WYEl
FI+
F2-
W9
D. AC output voltage builds up, but field breaker
trips.
To correct a problem, answer the question of the step
either YES or NO. Then refer to the step number in the
answer column and proceed to that step next.
Letters A through P in the Test Procedure column
refer to detailed procedures in the Adjustments and
Tests section, pages
8-15.
TABLE A. No Build Up of AC
Output Voltage
1. Is Field Breaker CB21
2.
3.
4.
on control panel ON?
Connect jumper wire across
terminals of Field Breaker,
CB21. Does AC output
voltage build up?
If voltage builds up
REPLACE FIELD BREAKER .
Push to reset Field Breaker.
Does AC output voltage
build up?
If voltage builds up but
is high, low, unstable, or
causes tripping of Field
Breaker, refer to Tables
B, C, or D.
Disconnect alternator stator
leads 1 & 2 from TB21·1 and
TB21·2 on VR22. Is reference
voltage across 1 & 2 20 VAC
or more?
DC
OUTPUT
VOLTAGE
4
3
7
2
B
Yes No Test
Proc.
2
3
-
4
-
4
14 13
CRI2. CRI3. CRI4
CRIS. AND CRI6
ARE ON VR21
VOLT. REG.
P.C. BOARD
VR21
TB21
CMR21 T21
TI THROUGH
T4 OR TI2
REFERENCE
VOLTAGE
CB21
0
0
VOLTAGE
REGULATOR
ASSEMBLY
FIGURE 22. GENERATOR-REGULATOR ELECTRICAL SCHEMATIC