This was under the covers of listed equipment, not premisis wiring.
Really?
IBM used them for the convenience outlets in all of our old mainframe machines. The secondary was completely floating.
If these outlets where intended for 'convenience' it sounds like both a violation and premise wiring.
Just because IBM was huge and did this does not make it right.
I took this thread to be about a audio system in a home, in that case the outlets must be supplied from a grounded system.
