Comment by jchw
3 months ago
Personally I would just wire some NEMA 240V outlet and then have a separate adapter with a pigtail of that receptacle type and a workbox with the UK receptacle. It's a little unwieldy, but it puts the questionable hackery outside the realm of the building inspection at least.
Whether it's actually safe I though, that I am curious. Obviously the kettle can get the 240V potential it expects, but the neutral is center tapped out of the split phase transformer, right? Not sure how people wire this. (Doesn't the neutral wind up having to be one of the hots instead?)
Hmm, yeah! I hadn't thought much about the differences between UK and US 240VAC service.
In the US, it's 240V 60Hz, split-phase with center-tapped neutral, and an independent ground wire.
In the UK, it's 240V 50Hz, single-phase with independent neutral and ground.
Frequency difference should be within design tolerance. and if my EE memory serves, the phase difference should be acceptable -- just measured from a different zero reference point. The neutral from the wall would be unused, and the ground would be wired as usual.
I'll think this through thoroughly though, I was definitely glossing over those details, so thank you!
Basically my concern is, ordinarily the potential from neutral to ground would be roughly 0V with some slack. In this case, though, the potential from neutral to ground would necessarily be 120V. I have no idea what the implications of that may be, but it seems important.
Go for a German kettle instead of a British one. Schuko wall plugs are reversible, so there will be no assumptions about neutral vs. ground.
Both live and neutral wires have to be treated as if they were both live, because 50% of the time they'll be swapped around.
I think it works if the US neutral is left unused (terminated in the electrical box).
E.g, something like this:
I think this is right, but I'm not 100%. The kettle should get what it needs, but I'm less certain whether a GFCI or ArcFCI breaker would have opinions that must be accounted for. I'll check with someone more qualified than myself to be sure!
6 replies →