Ours seem to stress the fuses untill one time you switch on and they blow - both of them - big time ! The older stacks with isolating transformers are kept in the older theatres - where I think they replaced the circuit breakers with six inch nails a few years ago.
We only have one theatre with all this fancy isolation monitoring equipment fitted and we did have some problems with alarms going off during the first few days. The company came back in and adjusted things and I don't think we've had any problems since. There are video scope stacks in use in that theatre area which have Sony monitors on the top, so I'd be surprised if they were not used in this particular theatre.
