The "Grounded Neutral Wire" is white. It is a full-fledged current-carrying conductor. The NEC calls it a "grounded circuit conductor". The green is an Equipment Grounding Conductor". It normally carries no current. I suspect that you need black, red, white, green.

So, "three wires" is understood to mean "four wires"? I don't mean that to seem sarcastic. I'm really asking seriously because it seems to defy common sense to use terminology that is so confusing.

I recently ripped a whirlpool tub out. It was dedicated, 120V with a 15A GFCI circuit breaker. It was hard wired with regular 14/2 Romex. It was to code, as it came out of a house that an electrician had built and lived in for several years. There was no extra ground wire to water pipe or anything like that. Chassis and extra grounding is required outside for hot tubs and pools. Its purpose is to put all metal parts at the same potential as the earth.

"So, "three wires" is understood to mean "four wires"?"

Only current carrying wires are counted, the bare or green ground wire is strictly for faults and may not be used in any capacity to carry current except for a fault.

Cables such as NM (Romex) for fixed installation count only the current carrying wires and are described as 14/2 with ground. Flexible cord counts the ground wire also. Consistency and logical naming aren't the strong suits of the NEC and electrical industry, as with many old industries.

I never did see what made bus driver think there was a need for a red wire in this setup.

Don't get your advice from the sales people at the big box store. Some of them are very knowledgeable, and others will make up an answer with almost no connection to reality. You are better off studying the instructions.

Well...

I suppose that I could simply wait until the tub arrives, and just look at how many wires there are coming off the motor. Still, while of course it is true that "12/2 cable" refers to a cable that actually has three wires, I'm having a hard time believing that the diagram would not show every wire, that there would be "implied" wires not shown on the wiring diagram.

I think the term "grounded neutral" just threw me because it sounded like there was supposed to be something unusual done to the neutral wire. Subsequent reading has revealed that this is just the correct (complete) term for the neutral wire: it's groundED, not groundING. So, I'm 99% certain that it's the same setup as bigbird described.

Thanks for the replies, everybody.

I don't know why this is at all confusing. The first sentence of the instructions says it all.
""The whirlpool should be installed on a 120 vac, 15 amp dedicated circuit."
All they are saying is that a neutral and ground are "essential". Duh, of course they are. Without a neutral there is NO 120v.

You need a typical, standard, 12/2 or 14/2 circuit to this tub. You need to use a 15A breaker.
14/2 is fine if the tub is not that far from the panel. Use 12/2 if the circuit is about 100' or more.

In my haste this morning, I scanned right past the 120 volt reference. The third red conductor is not needed in this application.

'Neutral' is not used in the NEC in connection with 120/240 V service.
The conductors are the "groundING conductor" (green/bare/green-yellow) and groundED conductor (white/natural).

'Neutral' is a carry over from 3 phase service.
Delta 3 phase does not even HAVE a neutral.
It is used in Y 3 phase service.

Just about anyone will understand what you mean if you call the grounED conductor a neutral though.

The instruction writers are just being a little pedantic in their description.

I figured it was just the terminology that was confusing me. The term "grounded neutral conductor" was unfamiliar, and after I read what it was, it seemed superfluous, as petey racer points out (well, duh). But in life and death contexts, I always like to err on the side of caution when I'm not 100% certain. :)

Thanks again.

When you get the unit it may only have two wires, a black and white. The third is the grounding screw or it may be a green wire. You need to run 12X2 W/G romex wire if in the house else us UF if you bury it. (You could use #14 but you have already purchased #12. The black goes to the black, it is the hot wire. The white goes to the white, it is the neutral. The bare wire goes to the grounding screw or green wire. For this connection use a crimping splice. This is the most important connection and your life may depend on it. In the box the black goes to the breaker, the white to the neutral bar with the other white wires and the bare wires goes to the ground bar with the other bare and green wires.

Gilshultz,

I just wanted to say thanks for the clear and concise answer to this question. Often answers to electric code questions are used to show off one's technical knowledge rather than answer the question (the "I know more than you do, that's why I get paid the big bux" type of answer.) Clearly your answer was a direct response to guitarmaker's question and was spot-on. Nicely done!

Mark

>I just wanted to say thanks for the clear and concise answer to this question. Often answers to electric code questions are used to show off one's technical knowledge rather than answer the question (the "I know more than you do, that's why I get paid the big bux" type of answer.) Clearly your answer was a direct response to guitarmaker's question and was spot-on. Nicely done!

Mark

What the...?!?

Gilschultz, is that you?