I spent nearly 12 years working on navy ships, which (are supposed to have...<G> ) are completely UNGrounded, I.E. to get 120 volts you have to have 2 hot wires(at roughly 60 volts each), and no neutral, Each circuit had 2 fuzes, 1 for each leg.... I learned a long time ago, that for current to flow you must have a complete circuit... Since the neutral goes back to ground somewhere...your going to have current flow.....