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kudzu9

Questions concerning wiring a hot tub

kudzu9
17 years ago

I originally posted this in the electrical forum, but got a response that basically said if I didn't already know how to wire a hot tub, I shouldn't try it. I'd just like some more opinions, so here's my post.

I've done lots of home rewiring and know what I'm doing there. However, my neighbor is buying a hot tub and wanted to know if I'd help him wire it up, and I could use some advice on doing it right.

He's got a 200amp main panel and room for a 220V breaker. He'll have a run of about 20' of wire between the breaker box and the hot tub. He told me that the wiring the guy at Home Depot recommended has 4 conductors encased in a flat cable; 3 of the conductors look to be about #8 stranded, and the 4th conductor is much smaller diameter. He also has a weatherproof hookup box that contains a GFCI, which I haven't looked at yet.

At the service panel end I'm presuming I'll connect the red and the black to the breaker and the other two wires to the ground bar. At the other end of the cable, where it hooks up to the GFCI, is there anything special to know or will that wiring be obvious?

I'm also recommending that he run the wiring through conduit rather than just do a direct bury in the ground. In this kind of application, are there two kinds of wire, one for direct bury and another for running in conduit?

I would assume that there should also be some distance between the hot tub and the GFCI box: what is the code requirement?

Is there anything else I need to know to be safe here?

Comments (10)

  • muddy_water
    17 years ago

    I'd run #6 four conductor wire....Cable not single 3/4 or 1inch conduit...Panel to the Service hooks up the same. You codes can be different but for me the code is the service panel can be no less than 5ft from the tub but no more than 10 away. Basicly you cannot be able to reach the box from the tub. GFI to the TUB make sure the Neutral is hooked up correctly to the GFI breaker...and test it...

  • kudzu9
    Original Author
    17 years ago

    muddy_water-
    Thanks for the ideas.

    Anyone else with tips or readable references I should check out?

  • huskyridor
    17 years ago

    I agree with the guys in the electrical forum.

    When I hear statements like this it frightens me to know that they're fixing to do something like energize a portable tub on the advice of a Home Depot aisle worker.

    QUOTE" At the service panel end I'm presuming I'll connect the red and the black to the breaker and the other two wires to the ground bar. At the other end of the cable, where it hooks up to the GFCI, is there anything special to know or will that wiring be obvious?

    He told me that the wiring the guy at Home Depot recommended has 4 conductors encased in a flat cable; 3 of the conductors look to be about #8 stranded, and the 4th conductor is much smaller diameter. He also has a weatherproof hookup box that contains a GFCI, which I haven't looked at yet. "QUOTE

    Whatever you do DON"T TAKE A JOB LIKE THIS LIGHTLY.

    Your safety and that of the bathers depends on an installation that meets code.

    Here's what I use for my installs.
    60amp 240volt GFCI breaker installed at the existing power center or a sub panel (NO EXCEPTIONS)
    2 #4awg 1 #6awg 1 #8awg, I use THHN/THWN inside of 1 1/4" sch40 a&u conduit. Mine may have higher amperage loads because the pumps are 5hp each so I have a larger breaker and wire size than you might need.

    IMO, if your unable to determine your amperage load and size the appropriate breaker/wire size for the tub and are unclear on the manner of wiring in a GFCI breaker "PAY A PRO"

    just my .02

    See ya,
    Kelly

  • muddy_water
    17 years ago

    huskyridor is right....I had a weak moment..Hire a Pro!!!

  • huskyridor
    17 years ago

    muddy, you really didn't have to take my side because there aren't any sides to take, LOL.
    This and the other forums I frequent are about enlightening those with less knowledge in an effort to educate them.
    My position is exactly as I stated it.
    This is most definitely not a job for those who aren't completely intimate with the job at hand.
    I'm not trying to knock the poster or his mechanical aptitude at all, I'm simply posting my take on his request for assistance.
    I'm also not knocking the aisle workers at Home Depot either. These guys do a great job assisting Do-It-Yourselfer's. But, this is a job description where the man at Home Depot should have told him the same thing I did.

    See ya,
    Kelly

  • dazyjune
    17 years ago

    We found this site when trying to figure out what all we needed to do before ours was delivered...Hope this helps some! I do remember they said at the tub location, they needed an excess of at least 5-6 feet of wire to wire it into the tub or they would not be able to do it! More is better!

    Here is a link that might be useful: GFCI wiring diagram

  • muddy_water
    17 years ago

    Kelly, But you were right and I should have posted a warning just as you did..Having a electrical background before I got into this business I should have known better. Wiring a tub for a neighbor and not really sure what I'm doing would leave alot of sleepless nights in my future anyway.

  • dart_2007
    16 years ago

    I hired a pro journeyman electrical contractor from a large local firm (FL) to pre-wire before the hot tub was delivered. He installed 3 wire conductor cable instead of 4 and says "it's no big deal - you wire the ground and the neutral to the same connection anyway, so it's manufacturer's recommendation and not code". Another electrician from a competing firm says he is wrong and it needs to be replaced and done right. What say you?? What else do I need to be aware of?

  • ausman
    16 years ago

    If this circuit is protected by a gfi which it should be, then it is wired incorrectly. The neutral and ground must be isolated from each other on the load side of the gfi!

  • km_21
    16 years ago

    Running 3 wires (2 hot + shared ground/neutral) to a sub panel of most any type is a bad idea. In our area, it violates code.

    Current runs through a neutral wire in a normal situation. Simple fact of electricity is that current flows in a loop, if there is current flowing in one wire, then there has to be an equal amount of current flowing in some other wire. (You could think of it as going out the hot and coming back on the neutral, but this is not technically accurate.)

    If you have only 3 wires going to the sub panel (or Hot Tub shutoff box), then some current could/will flow in that third wire. But that wire also has to be the safety ground, through which (under normal circumstances) current must never flow.

    One good reason why you can't allow current to flow through a safety ground is that (for large cables) the safety ground is thinner than the current carrying wires. So if for some unknown reason it had to carry the load, it could burn up before the breaker trips. Another is the use of GFCIs.

    So while having a GFCI connected this way is a no-no, it's just a bad idea all around.

    In some 220V devices, no current runs through the neutral, but then there wouldn't be a neutral connection to the device. As I understand it, hot tubs are usually 4 wire (2 hot + neutral + ground) devices. Dryers are usually just three wire devices, for instance, from the final breaker panel to the dryer, since all the current flows along the two hot wires.

    Hire the competition!