Wiring Question


Old 10-09-00, 08:20 AM
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I am finishing my basement in a newly constructed home. I have a third bathroom down there that I will eventually finish,but because of cash flow, I'll probablly wait until next year to do so. On the left hand side of that bathroom is our laundry room that I am going to finish now! In the laundry room is our circut panel. My question to you is my wife would like a whirlpool tub installed in that bathroom. We already have it rough framed for a 6' tub. Will I need to run a seperate electric line to that tub for the motor? If so is it a normal outlet or does it have to be 220? You guys helped me 2 months ago run my receptacles around the perimeter of my basement and we passed the inspection -THANK YOU!. If I need a 220 recptacle there can you walk me through the proceess? When we wired the rest of the basement we used 12/3 Romex that had a red wire, white wire, a black wire and a bare copper wire. Can I use the same wire to run this next line? I would be making the tub it's own seperate circut to the panel. I just need to know if I should, and how to run it so I can proceed with drywalling my laundry room. Drywall is being delivered today. Any help that you could give will be greatly appreciated. Thanks again for your previous help in running our receptacles. It was a great feeling to do it ourselves and have it pass inspection. You guys are all great!!!!!
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Old 10-09-00, 11:11 AM
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You need to call around and find out what a whirlpool tub of the type you have in mind needs. If it's 220V @ 20Amp, then your 12/3 wiring would be OK. But if they require a heavier circuit, you'll need some bigger wire. I'd go ahead an put 3 wire w/gnd in place, that way you can run 220 if needed. The extra wire won't hurt if you don't need it.
Old 10-09-00, 11:56 AM
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It all depends on what model you buy. Most are 110, but some are 220. You will need a minimum # 8 solid copper ground according to the NEC. All metal piping, motor frame, and all metal parts of electrical equipment associated with the tub must be bonded together. Although you are covered up to 20 amps with #12 wire, I would use 10/3 with NO ground, and run the #8 ground parallel over to the tub. You can always not use the red wire if you buy a 110 volt model later. This way you won't have to worry about busting holes in your new drywall later.

If it turns out to be a 220 v model, all you need to do is plug in a 2-pole breaker in your panel, wire a hot to each pole (black and red), wire the neutral to the neutral bus bar and the ground to your ground bus bar. (If your panel contains the main disconnecting means to your whole house your neutrals and grounds attach to a common point.)

As far as a plug, no 220 equipment uses a standard 110 v receptacle. But even though the NEC permits it, I would suggest hard-wiring the tub. I just don't like the idea of plugs and tubs. But if you do go for a receptacle, it must be GFCI protected and located at least 5' and not more than 10' from the inside wall of the tub. If you hard wire it you must protect that circuit with a GFCI breaker. All other receptacles located within 5 feet of the new tub measured horizontally along the walls must also be GFCI protected, as do any type of electrical fixture located vertically within 7'6" above the FULL water line in the tub (i.e., light fixtures). Any switches located within 5' of the tub must be bonded to the tub's bonded equipment.

Another requirement is that there be an access panel or door through which you can get to all electrical equipment associated with the tub, i.e., motor, heater, junction box, etc.

These are the good bits from the Code, but there are other requirements in the NEC with regard to a hot tub. You may be able to find a how-to book on whirlpool tubs at your local home center, or online, which will pull out all the appropriate articles from the electrical code. The alternative is to buy the whole 644 page NEC volume, where every article sends you to another and finding all the applicable regs could take a month!

Another alternative is, if you plan to have the installation inspected, obtain the name and number of the inspector and ask him/her any specific questions you have during installation. I have done this and found them to be very helpful and coutreous. They are there to help with personal and fire safety, they care, and they don't want to have to flunk you and make subsequent trips and more than you want that.

Hope that helps.

Old 10-09-00, 04:43 PM
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The first thing that concerns me is whether the one asking the question is sure that this tub is a whirlpool tub or a hot tub. If this tub is truly a whirlpool tub, I have a few different intrepretations of the NEC involving the wiring of a whirlpool tub than the previous replies.

The following is based on minimums of the NEC only. This reply is in an attempt to let you know the intent of the bonding grid and what other requirements are. Anything above the minimum is great. Just wanted you to know the minimums to make you able to decide how much more than the minimums you want to go.

The statement that said that you will need a # 8 solid copper ground is somewhat right. This is not a normal grounding. The #8 is a bonding grid that is not designed to be connected to the electrical system except by incidental continuity through the motor etc. that has an equipement grounding conductor {green}. This bonding grid is designed only to make all pieces of metal 4" square or larger one entity to eliminate any difference of potentiallity. All metals 4" square or larger are required to be bonded together but not to the electrical system. You are not supposed to install a #8 from the panel grounding system to this whirlpool tub or even a swimming pool for that matter. This #8 is a bonding grid, not a bonding ground. The source of the bonding grid is the metals of the whirlpool tub not the electrial system.
You are required to have a disconnect within sight of the whirlpool tub motor. This form of disconnect can be in the form of a switch that disconnects all ungrounded conductors or even a receptacle and plug that disconnects all ungrounded conductors, but a form of disconnect must be in sight of the motor of your tub.

All electrical whether 110 or 220 and hardwired or with receptacle must be GFI protected serving a whirlpool tub.

The requirement of 5' away from the whirlpool tub is not present. This 5' requirement is for hot tubs not whirlpool tubs. Any wiring around the whirlpool tub is controlled by chapters 1 through 4. If you have a receptacle in a bathroom it must be gfi protected but lighting or anything else is not required to be GFI protected.

The disconnect is not required to be 5' from the whirlpool tub.

Switches are not required to be bonded to the metals of the whirlpool tub with the #8 bonding grid, unless they are associated to the tub and not double insulated.

I suspect that the replies that mentioned a lot of the requirements ahead of me were mixing hot tub requirements with whirlpool requirements. Whirlpool tub requirements are located in 680-70 through 680-73. The requirements of a whirlpool tub is very short and not near as detailed as hot tubs or swimming pools.

The following is a copy of the commentary found in the NEC Handbook written by editors of the NEC.

NEC Handbook;99

Hydromassage bathtubs (see definition in Section 680-4) are required to be protected by a GFCI. In addition, all 15- and 20-ampere receptacles within 5 ft of the inside wall of the hydromassage bathtub are required to be GFCI protected. Except for this protection, hydromassage bathtubs are treated the same as ordinary bathtubs. See Section 410-4(d) for special requirements relating to cord-connected fixtures, hanging fixtures, and pendants near bathtubs. Also see Sections 210-8(a)(1) and 210-8(b)(1) for requirements for GFCI protection of bathroom receptacles.

Hope this helps to clear up a very common confusion between hot tubs and whirlpool tubs.


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