arcing on 13.7kv transformer inlet

[zorgglub]

hi guys,
it has been reported to me that on a distribution transformer (750KVA , 13.7 Kv) an arcing had caused the definitive damage of the transformer.

i was wondering if some of you already experienced this kind of problem , and if the caps on the unsused HV inlets are sufficent in term of insulation , as this transformer is in a tropical country (Haïti to be precise).
the local electrical engineer is only focused on a sabotage , because of the hole in the cap , he seem to ignore the effect of high voltage on thin insulation
so i would like to have you opinion on that problem , who seems to me to be a insulation defect of the inlet connector and maybe a cap not appropriate for securing the unused inlets.
thanks in advance

best regards

Jean Michel

 

[zorgglub]

Link

 

[zorgglub]

Link
Link
Link
Link

pictures of arcing

 

[stevenal]

Bushings grade the voltage properly, caps are for keeping the dust out during shipping.

 

[Marmite]

Stevenal is right. You need a bushing well plug, not just a plastic cap.
Google bushing well plug and several suppliers come up.

Regards
Marmite

 

[cmw1971]

Those plastic caps are not sufficient. When you have unused deadfront wells, you should be using a bushing well insulated plug. If you have unused inserts in the wells, you should be using the appropriate insulating cap. Some applications use arrestors instead of the protective caps. As stated above, those caps in your photos are for shipping and storage purposes.

 

[zorgglub]

many thanks guys , do you have some references or regulations for me to study about shipping caps ?
unfortunately , the supplier / installer saw the word "sabotage" and as this sound good to him (cancellation of warranty and supplying us a brand new transformer ) i predict we 'll have a hard time to convince him to repair and correct the installation , at his cost.
thanks again , from Haïti
with my best regards

Jean Michel

 

[unclebob]

See attachment. Contractor will need to remove oil, replace the damaged wells and use the proper bushing plug. Contact the transformer manufacturer.
Looks like Pioneer Transformer to me... now Pauwels.

 

[zorgglub]

thanks again to all of you , this was very helpful.

Jean Michel

 

[zorgglub]

end of the story : a Dominican company is going to check the transformer (insulation etc.), replace the damaged bushing and put insulations plugs in unused connectors. thanck to ABB and Eminsa .

best regards

Jean Michel