You're getting off base somewhat.The Deez is correct in the cause. I've never seen a pigtail GFCI on a cord, but then I'm not that experienced either. Would these connect similar to a GFCI receptical in that the HOT (Black) wire would be attached to a BRASS clip, while the NEUTRAL (White) would be on a (SILVER)? At the very least, it should indicate which is HOT and which is NEUTRAL. ??
There is no polarity on a 240 volt circuit.He did add a double pole 30 breaker and i'm told it's 12 gauge wire.