Is possible increase the BIL (Basic Impulse Level) on an existing transformer

[Freshsurfer]

Hi, we're detailing the electrical installation for a large underground mine.

One of our equipments on our scope of supply is a 4.5MW 34.5kV to 4.16kV transformer.

This trafo is already done on ABB's shop and was fabricated with a BIL = 200kV.

Our client is asking to change the BIL to 250kV, this is possible?, even this trafo is ready to go, it stills at the ABB facilities.

Thanks!

Raul

 

[ScottyUK]

Ask ABB. If the bushings are the limiting factor then it may be possible, although it will depend on whether the transformer can accommodate a larger bushing.