Westerbeke 20.0 BEDA - BE Generator AC Troubleshooting; Troubleshooting No;Low;Unstable AC Output

BE TROUBLESHOOTING
NOTE: AC GENERATOR TROUBLESHOOTING MUST
BE PERFORMED WITH ENGINE OPERATING AT 60 HERTZ
FAULT
PROBABLE CAUSE
No AC voltage output at no load.
Residual voltage produced at no load
15 • 20 volts AC.
Low AC voltage output at no load
60 -100VAC.
High AC output voltage
150 VAC or higher.
· Unstable voltage output.
AC voltage drop under load
60 ·100 volts AC.
,-------------...,
EXCITER
STATOR
1. Short or open in the
main stator winding.
2. Shorted pozi-resistor
on exciter rotor.
3. Four or more shorted or
open diodes on exciter rotor.
1. Blown 6 AMP buse fuse
auxiliary circuit feed to AVR.
2. Faulty voltage regulator.
1. Open or shorted diodes in
exciter rotor 1 to 3 diodes.
2. Open or shorted exciter
rotor winding.
1. Faulty voltage regulator.
1. STB pod on regulator
needs adjustment.
1. Diode(s) on exciter rotor
breaking down when load is
applied (inductive) 1-3 diodes.
r-----~----------,
RED
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t-------1
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I I RDTDR FIELD I
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STATOR . I
,---.....,I I I
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I I
I
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AUX
I
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.-----' I I
I L-----~----------~
-----
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L- ---------.J
RED
RED
BLUE
YELLOW
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f Engines & .Generators
3,9
4. Short or open in exciter
stator winding.
5. Short or open in rotating
field winding.
3. Shorted or open main
stator auxiliary winding.
3. Faulty voltage regulator.
2. Faulty voltage regulator.
Rm
RED
RED
®
W2
FUSE
U1
BLACK
GREER