Sincro HB4 - Troubleshooting

FAULT POSSIBLE REASON CHECK / REMEDY
NO VOLTAGE
FaultyAVR
• checkthefuse
• replacetheAVR
Faultyrectierbridgeand/orsurgesuppres-
sor
• checkrectierbridge
Faultystatorexciter • checkifthestatorexcitercircuitisopen
Mainwindingfault
• checkstator/rotorwindingsresistances
• checkstator/rotorwindingsinsulation
resistance
Demagnetizedmachine
• excitethealternatorbyapplyinga6-12
voltageacrosstheexciterterminalsfora
second,respectingthepolarities.(Engine
isrunning)
Brokenconnections • checkallconnections
LOW VOLTAGE
Referencevoltageisnotsetatdesiredvalue
• adjustvoltagewithpotentiometer«V»on
theAVR;
Under-frequencyprotectonnotproperly
adjusted
• check/adjust,thevalueofunder-frequen-
cyprotectionfor50Hz(60Hz)nominal
frequency.
Enginespeedlow
• checktheenginespeed(voltagefrequen-
cy)
FaultyAVR • replacetheAVR
HIGH VOLTAGE
Referencevoltageisnotsetatdesiredvalue
• adjustvoltagewithpotentiometer«V»on
theAVR
Sensingconnectionopencircuit • checkthesensingconnections
FaultyAVR • replacetheAVR
UNSTABLE
VOLTAGE
AVRstabilityincorrectlyset
• checkthecorrectDipswitchesposition,
adjuststabilitywithSTtrimmer
Enginespeedunstable
• checkwiththefrequencymeterifthere
areoscillationsinenginespeed
FaultyAVR • replacetheAVR
FormorequestionscontacttheSincroAfterSalesService.
7.3 Troubleshooting
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