Seperately derived power systems?

[iwire]

I need help finding a good transformer for this application.

Do a Google search for balanced power systems.

 

[kwired]

One reason for the wide prong plugs on equipment is to insure that a particular part of the wiring/controls/etc. is operating not far from ground. Is the reduction from 120 volts to 60 volts good enough to maintain the UL listing of equipment that is required to have a polarized plug and cord set? (Think of Edison base light bulb sockets.) Or should you just be careful not plug such equipment into a balanced receptacle?
My impression is that a balanced distribution system is used for specific types of loads or environments, and just plugging random conventional loads into that system would not be a good idea anyway?

And then, just to muddy the waters further, there is the separate topic of older RV inverters and some current MSW inverters which produce "balanced" power just to reduce the cost of the electronics. Attach them to a wiring system with a ground-to-"neutral" bond, and the magic smoke comes pouring out.

With the Edison base lampholder I'm fairly certain that the shell is not necessarily required to be connected to the grounded conductor, but if the circuit uses a grounded conductor then it shall be connected to the shell and not the center pin. This 60/120 system would not use a grounded conductor for a 120 volt circuit, just like a 240 volt circuit on a 120/240 system does not use a grounded conductor.

Edit to add: See 410.90

Also see 647.7 and 647.8