STATOR EARTH FAULT FOR HIGH VOLTAGE GENERATOR
I gatta such indication in 11MW HV generator during synchronization time, as result we could not be able to synchronize machine....after troubleshoot we came to conclude maybe Lightening Arrestor or Voltage Transformer (Ground transformer ) maybe defective...could someone tell me what to do??? how can we test 9KV Lightning Arrestor??? or someone can suggest what possibly causes as per entitled subject.

VOLTAGE TRANSFORMER DETAILS

1 PHASE, 50VA/ Phase

Class BZ

Ratio 6350/110V

Line Voltage=6350

serio no:RVB 349017

LIGTNING ARRESTOR DETAILS

9KV

50/60 Hz

DUTY CLASS

10KA

 

Matembo... the information you provided is too vague

Typically, modern day lightning arresters are essentially considered as maintenance free. Some older types were "testable!"

Can you provide information such as manufacturer, IEEE or IEC classification, MOV-type, etc, so that a meaningful reply can be posted. Perhaps, you should can contact a commercially available HV testing firms to help you?

Regards, Phil Corso