Lets get real fuzzy...if E57 is correct and this tub is fed with a "feeder" because the last overcurrent device at the tub (which I disagree with, I think it would be a non-fused disconnect and not an overcurrent device), then all "equipment" that is fed downstream from a "fused disconnect" (or overcurrent device)such as heat pumps or air conditioning compressors which sit outside of the building would be fed from "feeders" and require a GEC? This is getting real fuzzy!