ref: 120/240 devices

[Ken Bakhaus]

Another important point that has not been mentioned in any of this discussion is circuit protection. If the circuit protection, fuse, circuit breaker, etc, is on the primary side of the transformer, it must also be changed/switched with  switching of the primary voltage to maintain the same level of protection.

Another interesting point from someone who has worked in the circuit protection industry - The European safety agencies are much more concerned with personal safety (shock) in writing their standards whereas the north Americans are more concerned with fire and equipment, including wiring, protection. This evidenced by the greater crippage and clearances required between live conductors, conductors to ground and conductors to where one can touch a control such as a switch handle in the Euro specs. Higher dielectric materials are also required over there. Part of it is of course the higher voltage but even lower voltage equipment has greater requirements. Eventually the requirements between the two areas will converge as all adopt IEC standards. Another contributing factor to these differences is that Euro building construction uses much less in the way of combustibles being more brick, stone and stucco oriented.

just some more points to consider.

73
Ken K8PAO

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