I am not an electrician, but I have equpped the workshop/garage in two houses with a 230-240V GFI breaker, and then ran 12/3 w/grd to several wall boxes, then wired some of them so that the upper and lower receptacles were on separate legs of the 230V. The first was passed by the Summit County Ohio building inspector; the second by the City of Akron inspector. I am not certain this arrangement meets code, but it has worked for me without any problems, and I have tripped the GFI when cleaning out a sump pump clogged with debris (not a locked armature). The advantage of this arrangement is two fold: (1) any outlet can be fitted with a duplex receptacle in which each leg can supply 20 A at 120V to a tool or up to 20A at 240V, and (2) when you plug one tool into the upper 120V receptacle and another into the lower receptacle and run them at the same time (as I often used to do running a router and a Craftsman vacuum at the same time), the current losses through the wiring are cut in half compared to normal circuits (assuming each of the two tools is drawing the same Amperage. For the first garage/shop the double-pole GFI breaker was a special order from Square D, but that was 30 years ago. For the second garage/shop, all of the service entry and distribution equipment was from Siemens.
The Akron electrical inspector would normally only allow a single 230V outlet on a circuit, without GFI, e.g. for a compressor or dust collector or table saw. He and the electrician questioned my idea, and each tested it and found everything worked. I don't know if there are any potential adverse induction issues as can occur when unbalanced circuit legs are arranged inside metal conduct that is grounded.
Dave R.
