Installing a tub in place of where a previous owner had theirs. So I have 240 with 50Amp breaker/GFCI combo at the main and a 50Amp fused disconnect in the hot tub room. The wiring they used is all the same gauge and all black. The previous owner just cut the cables at the end without labeling them (jerk!). At the disconnect the ground (green) and neutral (white) are labeled but not the two hots (read and black). How does one figure out which hot is which?
Thanks,
Bryan

Hook 'em up to the breaker and meter them out. You'll have to leave either the ground or neutral disconnected, so you don't confuse the two, and you will be able to isolate which is neutral and which is ground. It doesn't matter which hot is which, but ground and neutral can make a difference.

Thanks Swine

>It doesn't matter which hot is which, but ground and neutral can make a difference.

You're saying I don't need to differentiate between the two hots (usually labeled red and black)? If so, I'm set. I can see the ground cable both because it's labeled green and because they have it grounded to the disconnect box. The neutral is also marked white and passes through the disconnect box. The remaining two wires are unlabeled and go through 50 Amp fuses in the disconnect box.

Does that make any sense, breaker, gfci, AND fuses? Maybe they got a deal on that disconnect box since it's the same as my A/C.

Thanks again,
bryan

That is correct, hots do not matter.

The breaker in the house panel is adequate since it's GFI, and the disconnect near the spa location is just fine. It doesn't need to be fused, but being fused won't cause a problem, as long as the fuse contacts remain clean and corrosion free. The disconnect is there because code requires a disconnecting means for the tub, no closer than 5 feet from the nearest inside edge of the hot tub, and in plain sight.

Thanks charger.