Replacement of OLTC

[yiefang]

Hi,

i have a question on the replacement of On load tap changer. Usually what test to be carried out:-

1) Before replace the OLTC
2) During replace the OLTC
3) After complete the OLTC replacement.

 

[86ed]

Your question is too broad. What portion of the OLTC is being replaced? Any internal equipment replacement should involve the transformer vendor if possible.

 

[yiefang]

complete set of oltc (diverter switch + tap selector)

 

[prc]

Hope you are replacing with identical OLTC.After all connections are made,but before oil filling the transformer,check ratio error at all taps in raising mode and lowering mode.Check the diverterswitch contacts opearting correctly as per indications from driving mechanism.Check winding resistance at all taps and compare with earlier bench marks.Go by the tap changer manual guides.

 

[bacon4life]

Both models of tap changers we currently purchase require oil filling before mechanically operating them. Depending what you use for the recomended tap ratio and resistance measurement, it likely needs to be oil filled for that as well.