I am rearranging some wiring on a boat dock, where there were two jet ski lifts that were powered with 220v originating in a sub-panel (at the house) which has a 20a GFCI two pole breaker.
I was a bit surprised to find a 110v outlet was powered by one leg of that circuit (which further downstream powers the two jet ski lifts). The outlet is not GFCI itself. A neutral and ground are provided (separately) and the wire looks appropriate (though I have yet to open up all the conduit involved).
My question is that outlet and the 2 pole GFCI. I am somewhat familiar with the Multiwire Branch Circuits rule, but not 2 pole GFCI breakers. Can such a breaker legitimately protect a single leg outlet? Logically I would think so (since logically a leak of one leg is the safety issue it should be protecting against anyway), but code is ... well, different at times.
Also: an outlet tester inserted in that outlet reads correctly, but hitting the GFCI test button fails to trip the breaker in the panel. That might indicate faulty panel breaker of course. But it made me wonder if this was really legit overall.
My original plan was to take the 4 wire run, use only three, swap the 2 pole GFCI for a single pole GFCI and turn those two jet ski locations into general purpose 110v outlets. If this setup is legit, I could use all four wires, and have twice the current capacity and not even need a new breaker (well, except that it might be defective -- should a outlet tester trip it?).
So I think this boils down to: where a GFCI is required, can a two pole breaker provide the protection for an outlet only on one leg?
Thanks for any insight,