Westerbeke WPDS-20 Technical Manual page 97

T.60
TABLE A. (continued) Yes No Test
Proc.
5. Is exciter field voltage across
F1
+
and F2- on end bell
terminal block 7.0 VDC or
more? 6
-
If not. check wiring harness
W9 from end bell to VR22
terminals 3 and 4.
6. Is brush less exciter stator
(field) winding OK? 7 - K
I
7. Are diodes CRl. CR2, CR3,
CR4, CR5, CR6 in rotating
rectifier assemblies OK? 8
-
F
Check all diodes - more
than one may be
defective.
8. Are brush less exciter rotor
windings OK? 9
-
L
9. Is generator rotor field
winding OK? 10
-
M
10. Are generator stator
windings OK?
11
-
N
1l. Is commutating reactor
CMR21 OK? 12
-
I
12. Is reference transformer
T21 OK?
18 - J
13. Flash exciter field. Is
reference voltage across
1 and 2 now 20 VAC or
more?
14 5 E
14. Reconnect generator leads
1 & 2 to TB21-1 and
TB21-2 on VR22. Does
reference voltage build up?
-
15
15. Is regulator DC output
voltage across VR21-7 and
VR21-8 7 VDC or more?
See Figure 22. 5 16
16. Are SCR's CR13 and
CR16 OK? 17
-
H
17. Are diodes CR12, CR14,
and CR15 OK? 18
-
G
18. Replace voltage regulator
PC board (VR21)
- -
P
TABLE B. AC Output Voltage
Yes No Test
Builds Up, But Is
Proc.
Unstable
l. Are there any loose or broken
wires or connections on
voltage regulator assembly
VR22?
- 2
2. Is W9 (exciter field) wiring
harness from VR22 to End
bell OK?
3
-
3.
Does adjustment of Damping
Control R27 potentiometer
on VR21 result in stable
voltage?
-
4 A
4. Replace PC Board VR2l.
-
-
P
~
Do not replace the printed circuit board until
~
the trouble not on the PC board has been
located and corrected to avoid damage to new PC board.
TABLE C_ AC Output Voltage Yes No Test
Builds Up, But is
Proc_
High or low
1. Is set running at correct RPM?
(See appropriate engine
manual to set RPM)
2
-
2. Does adjustment of Voltage
Adjusting knob for R22
on VR22 result in correct
output voltage? -
3
A
3. Does adjustment of
potentiometer R26 on VR21
result in correct output
voltage?
-
4 A
4. Is correct voltage reference
V4 to VI, V2, or V3 on
VR21 being used?
Refer to Figure 6.
5
-
5. Are generator output leads
properly connected? Refer
to Figure 6. 6
-
6. Replace voltage regulator,
PC board VR21
-
-
P
~
Do not replace the printed circuit board
Uf.
~
the trouble nol on the PC board has been
located and corrected to avoid damage to new PC board.