Transformer

In my Company we heve 4 transformer,All different loads are run across,We have 2 Power control circut(PCC) In this PCC 2 incomer of the the transformer Connected to the Buscoupler, Whenever fault occurred in any Incomer in auto mode buscoupler lined up so all load comes in one transformer.......so my Question is which system apply 1.Buscoupler system 2. Parallel transformer system.....Thank you