Westerbeke 8.0KW-60Hz Service Manual page 85

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BT GENERATOR TROUBLESHOOTING/3 PHASE
NOTE:
AC GENERATOR TROUBLESHOOTING MUST BE PERFORMED WITH THE ENGINE OPERATING AT 60 HZ
FAULT PROBABLE CAUSE
NO AC VOLTAGE OUTPUT AT NO LOAD.
1.
Short or open In the 4. Open In exciter
main stator winding. stator winding.
2. Shorted suppressor 5. Open in rotating
on exciter rotor. field winding.
3. Four..ar more shorted or
,
open diodes on exciter rotor.
RESIDUAL VOLTAGE PRODUCED AT 1. Blown 6 AMP fuse 3. Shorted or open main
NO LOAD 15 • 20 VOLTS AC.
auxiliary circuit feed to AVR. stator auxiliary winding.
2, Faulty voltage regulator
LOW AC VOLTAGE OUTPUT AT
1.
Open or shorted diodes in 3. Faulty voltage regulator.
NO LOAD 60 ·100 VAC. exciter rotor 1 to 3 diodes.
2. Shorted exciter rotor winding.
HIGH AC OUTPUT VOLTAGE 1. Faulty voltage regulator.
150 VAC OR HIGHER.
UNSTABLE VOLTAGE OUTPUT.
1.
STB pod on regulator 2. Faulty voltage regulator.
needs adjustment.
AC VOLTAGE DROP UNDER LOAD
1. Diode(s) on exciter rotor
60 ·100 VOLTS AC. breaking down when load is
applied (inductive) 1-3 diodes.
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