Originally Posted by carlisle_bob
Do you have a four wire plug on the wall or is it three wire? If it's four then you have both neutral and ground. With three one or the other is missing (hopefully neutral). As noted in the other thread, there's no really easy way to do GFCI's at 240V.
Not saying there is a product you can buy, or that my idea would be up to code, or that i am a qualified EE, but it sounds semi-easy to me.
We're talking about - in north america anyway - two hots, a neutral, and an earth. Hot and neutral come from the pole. Earth is earth - a copper clad steel rod pounded into dirt. Or just your water main.
In NA the hots are strung around the house basically evenly so that you, on average, load both of them equally. They also supply large appliance power.
In essence, we are talking about GFI protection simultaneously on two hots. Conceptually, this would require that you cross-link two 110v gfi circuits such that when one trips, the other gets it's "test" button actuated. You could do that with relays, or active circuitry.
Having skimmed the other thread, i don't see why - and again here i don't know elecrtical code - i don't see why the protected breaker excludes an earth line.