OT: american vs european 220

The peak voltage from the power-carryingwires to ground is also an outcome of the design. My real point is that no device that requires 220V should care about the voltage to ground (within reason). I would certainly consider a 220V device that could not satand 220V between one of the power-carrying wires to ground ans being unsafe. But as various people have pointed out, many US 220V appliances do use 110V for something (controller, timer, etc). That's a bigger problem when running them in Europe Actualyl, I have amn instrument (I think it's my Tektronix 575 curve tracer) whic hahs sepprate wiring arrangements for 115V, 230V with the centre earthed and 230V with one side earthed. No, the last 2 are not a safety thing. Appranetly by having certain points of the transformer primary close ot ground you get slightly less noise in the instrument. -tony