mpparent,
If this is an existing installation, a check of the short-circuit & co-ordination study for your installation will indicate whether the fuse will clear before the main protective device operates. This should be apparent from the co-ordination curves for the transformer feeder.
Tuxedo, was any electrical testing done on the transformer prior to re-energization, and what were the tests done and the results? Were the results deemed acceptable for energising the transformer?
Were new 50/51 relays used after the breaker retro-fit, or were the original 50/51 relays used...
