Grounding a Transformer

[m_herrera202]

A step down 75KVA 3 phase wye transformer 490/277 to 208/120 recently went bad, it was located inside a building servicing a motor aparently it did not have a ground connection, my question is
would that be a possible cause why the transformer went bad?

 

[Smart $]

A step down 75KVA 3 phase wye transformer 490/277 to 208/120 recently went bad, it was located inside a building servicing a motor aparently it did not have a ground connection, my question is
would that be a possible cause why the transformer went bad?

IMO, not being grounded would not cause failure.

 

[augie47]

I agree. Lack of a ground would be way down on my list of possibilities.

Can you tell us how it was connected (Input 480v ?, was the 480/277 neutral connected to anything ? )

 

[conmgt]

What do you mean by bad? Internal short such as a breakdown in insulation or meltdown from overloading? Failure of the motor overloads? Low voltage on the primary side?

 

[Sparky Adam]

Probably dust build up on the plates... And if the humidity was high you could have a bridge for the current to flow.