I got called into work last weekend because half the building had no power. Turns out an outside light shorted out and brought down the subpanel. It was a 480 subpanel so it killed a bunch of lights and a transformer supplying 120 loads. This was normal power not emergency.
I have actually had a 120,000 sq ft building trip the main ground fault protection due to a leaky roof shorting out a single fixture.
It is my belief that this is not good. It may be acceptable by code and engineers but a single short in a 20 amp circuit should not kill everything.
Perhaps this proposal is a step in the right direction.
