On Thu, 15 Feb 2018 22:53:22 -0000, "James Wilkinson Sword"
wrote:

On Thu, 15 Feb 2018 22:41:19 -0000, wrote:


But what I'm interested in is do you ever have 220V devices connected to the same +/-110V wires as 110V devices, off the same breaker? If so, how does this breaker cope with THREE possible current flows?

The GFCI is "clever" as you say but a regular breaker only measures
the current on the ungrounded conductors, no matter where it ends up.
You can have both available at the same location and we even have the
devices to make it easy

http://gfretwell.com/electrical/5-20-6-20.jpg
The top one is 240v 15 or 20a, the bottom is 120v 15 or 20a.

My house is a lot simpler. 240V and 0V. All the 240V lines have a FUSE on them, none of this namby pamby circuit breaker **** causing false positives. I don't have to worry about crossing between circuits, there's only one 0V line, and it's the same as "earth". Both are wired together at the meter, then go back as the shielding on the armoured cable from the utility transformer. I often use earth instead of neutral, because having no circuit breakers, it's doesn't matter!

Yeah but when your RCD trips, the whole house goes dark. Then you are
on an easter egg hunt looking for the cause.