Transformer Installation Criteria

Dear All

I have another one for you.

Soon enough I am going to assist a 2MVAR transformer installation; this transformer is going to be in parallel with another one of the same rating but used as a hot stand-by. The two transformers are going to be connected to a bus-tie connector and if one fails a load transfer to the other is performed through the bus-tie.

Problem arised when I was informed that the newly arrived transformer is of a different model/brand than the existing one.

As a general rule I ask the following data:

1) Earth Fault loop Impedance of the transformer

2) Prospective short circuit current

Specifically 2) will dictate whether the rating of the gear and eventually the bus tie are suitable for the new transformer in short circuit current terms. As additional information I have also requested the % reactance of the transformer.

My question is; apart from the above is there any parameter which is required to know? and if over-seen it might impose future problems?

Thanking you once again

RC