Ted, you are right about where I got my 600V info from but I think that
you should not rely on anything arcing over at 600V. I have seen 220V
power strips run at 1500V ac indefinitely in humid atmosphere for testing
purposes. They were the normal $10 kind you can buy anywhere. The
breakdown voltage of air is rumored to be about 1kV/mm but it depends on
too many things. Based on this, the mentioned powerstrip should withstand
20kV (but the cables won't and it won't either, spraying and ion
currents build discharge paths very quickly above about 5kV). I feel
that using 1.5kV rated parts in the input side of anything connected to
spiky mains is the way to go.

Peter

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