Hot tub wiring and bonding

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ddubbs103

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Massachusetts
I have been reading a lot on outside hot tubs and have done a few with other people before, but reading all these threads has me wondering if these installs were right. I have a job to price out where the homeowner bought used hot tub and wants it wired. The questions I have is, the tub is going on side of house on concrete and after reading up on this I am confused on the equipotential bonding, is it needed and second question is I have not done a pool either so I was wondering what you bond the equipotential bonding conductor to, equipment ground cond coming from the feed ? sorry for long post
 
On a side note, I want to state that I think the requirement for any equipotential bonding around any prefab. prepackaged hot tub is ludicrious.
 
I have read that pdf and still really do not understand or does it answer the questions I have. I do not understand the wording it is really confusing. The equipotential ground, does that connect to the gronding electrode conductor any where? I really want to understand this article any help is appreciated thank you
 
I have read that pdf and still really do not understand or does it answer the questions I have. I do not understand the wording it is really confusing. The equipotential ground, does that connect to the gronding electrode conductor any where? I really want to understand this article any help is appreciated thank you

Author?s Comment: Equipotential (stray voltage) bonding isn?t
intended to provide a low-impedance ground-fault current path
to help assist in clearing a ground fault. The topic of stray
voltage is beyond the scope of this textbook. For more information,
visit www.MikeHolt.com, click on the Technical link, then
the Stray Voltage link.

FPN: The 8 AWG or larger solid copper equipotential (stray
voltage) bonding conductor [680.26(C)] isn?t required to extend
to or be attached to any panelboard, service equipment, or an
electrode.


BTW did you catch his illustration of the pool with an alligator in it?
 
It does connect to the equipment ground usually through the bond at the motor ,.. even if a double insulated motor is used... see 680.26(B)(6)(a)
 
Ddubbs103,

You stated in post #4: ?I really want to understand this article any help is appreciated thank you?

?For what it is worth, you are not alone. There are a large number of people (including me) who believe that applying Section 680.26 is pretty unclear for some installations and when applying it to spas and hot tubs it seems to get even less clear. I do want to say that CMP 17 has done an excellent job in providing some of the best language for this section in the 08 NEC. I just believe it needs more work (more language) to make it easier to apply, or to just ignore, for some installations. ? Many of us have been struggling with this for many Code cycles? (all of my comments are based upon the 08 NEC?)

I would never say that I have this all figured out (because I don't), but just responding to this helps me continue to work this out in my own mind? In addition, I have had many discussions on this and the input I have received from others has helped me considerably in understanding this. The following has helped me a great deal toward grasping all of Section 680.26?

First let me clarify that within Part IV of Article 680, the NEC refers to three different kinds of spas and hot tubs (other than therapeutic or hydrotherapeutic which are not in Part IV):

Self contained (defined in the NEC Article 680)
Package (defined in the NEC Article 680)
Field assembled (not defined, but should be self evident?)

The requirements of section 680.26 do apply to all of the above types regardless of whether these three types of spas or hot tubs are installed indoors or outdoors ? See Sections 680.42 & 680.43 (both refer you to Part II of Article 680 where Section 680.26 resides)?


In applying any of the requirements of Section 680.26 to ANY installation:
It may be helpful to remember that all of the prescriptive requirements in Sections 680.26(B) and (C) are only in the NEC to satisfy the performance requirements of Section 680.26(A). The language in (B) & (C) is only there to ?reduce voltage gradients in the pool, spa and hot tub area? ?as noted in (A).

This ?area? (for me) can be defined as three specific locations in and around the specified body of water:

1. The entire area inside the specified body of water including the conductive shell (assuming the shell is conductive, because some are totally nonconductive) and the water itself [Sections 680.26(B)(1) and (C)].

2. The perimeter area within 5 feet horizontally of the inside wall of the pool, spa hot tub [Section 680.26(B)(2)]. ?(for me, this is a reach distance?) ...yes ... the perimeter surface only extends out to a distance of 3 feet, but any conductive surface or object within 5 foot requires equipotential bonding...

3. All of the pool, spa, & hot tub associated electrical equipment regardless of its location [Section 680.26(B)(6)]. ?While my item 3 is certainly not an ?area? it denotes required equipotential bonding which could exist well beyond the 5 foot reach path noted within Section 680.26 ?


? All that being said, do select installations exist where applying ANY of the prescriptive requirements in Section 680.26(B) have absolutely no contribution toward satisfying the performance requirements of Section 680.26(A)? Personally, I believe there are some select installations where this is true. Nothing accomplished in Section 680.26(B) will do anything to satisfy the requirements of Section 680.26(A) ? for some select installations.

I do not believe you can just say: ?the requirement for any equipotential bonding around any prefab. prepackaged hot tub is ludicrous?. Unfortunately it is not quite that simple of a demarcation as to whether equipotenital bonding is necessary (? at least for me?). Personally, I can think of both package and self contained installations where equipotenital bonding is quite necessary. For example: When either of these units are installed outdoors on a concrete slab (and said slab is extending beyond the immediate side walls of the body of water), and said slab is in contact with the earth, the likelihood of encountering voltage gradients within 5 foot of the inside wall of the specified body of water exists? (this is just a single example) When the likelihood exists, I believe the equipotential bonding is necessary.

One example which comes to mind (where equipotential bonding is totally unnecessary) is a spa or hot tub installed indoors on the first floor of a wood frame structure above a basement and having a minimum 5 foot reach path from the inside wall of the spa to any conductive surface. For this select installation (I believe), there is nothing in 680.26(B) which contributes anything to satisfying the performance requirements of Section 680.26(A).

From here, the question is: are there other installations for which the performance requirements are not needed at all or only needed in part? I believe there certainly are (such as a spa or hot tub installed on an elevated wood deck which creates a nonconductive minimum 5 foot reach path, which is expected to remain nonconductive for the life of the installation...), but this is where it gets gray for more people, installers and enforcement alike.

This is just an insight of just some of the application of this Section, and this certainly does not address each and every installation you will encounter. I do hope others will contribute toward our mutual understanding of this difficult Section (personally, I need the help...).


Each individual installation needs to be examined to determine if ALL or ANY parts of Section 680.26(B) will make a contribution toward satisfying the performance requirements of Section 680.26(A).


Please forgive my loong post? many say I have trouble collecting my thoughts ... :) ? it could also be an example of just how involved the application of this Section can be for some select installations?


But, I do hope this is helpful, it is certainly helpful for me to just type it out? :)

mweaver
 
Thanks for for your thoughts and answers. This question to other electricians I know is a good one, everyone had somewhat different answers and most of them said they do not believe that a hot tub is required to have equipotential bonding. Trying to discuss with some is difficult because they are always right and others I think really do not know the answer either. Either way the more we discuss things like these the more I understand kind of, thanks again.
 
You should give your inspector a call. In my area they don't require a equipotential grid under a self contained hot tub. I think it's just a judgement call that they have made.
 
Ddubbs103,

2. ....yes ... the perimeter surface only extends out to a distance of 3 feet, but any conductive surface or object within 5 foot requires equipotential bonding...


mweaver

Nope,... this could add thousands of dollars to a hot tub located outside near a dwelling ,.. think of all the conductive surfaces or objects ...

How would one bond a doorbell button or the head of a nail?

Heck ,the code allows small metal objects right in the water with you without bonding them,.. but if it is outside the tub it all of a sudden requires bonding ,..??? Not in my opinion
 
M.D.

Thanks for correcting my blanket paraphrasing on this point (It is important that my statements do not leave others with that thinking, and this was a poor choice of phrasing on my part...).


Yes, I do agree (and you are correct) small objects do not require bonding as noted in Section 680.26.

mweaver
 
Hot tub wiring and bonding

I know of a outdoor hot tub that is going on an existing concrete slab. How would any of you satisfy 680.26?
 
LawnGuy,
Author?s Comment: Equipotential (stray voltage) bonding isn?t
intended to provide a low-impedance ground-fault current path
to help assist in clearing a ground fault. The topic of stray
voltage is beyond the scope of this textbook. For more information,
visit www.MikeHolt.com, click on the Technical link, then
the Stray Voltage link.

LawnGuy,

Speaking of Stray Voltage did you see the Violation photo by Joe Tedesco,
the one of the "Floating Receptical"?

If memory is right, he was visiting a HO, and found him in the pool relaxing and watching a television.
He was floating on a air mattress,
with the television sitting on his tummy,
with the television plugged into a Floating Receptical
(see attached photo).

Having done testing in a hospital environment,
I assure you that a little "Stray Voltage" can kill a heart pace-maker,
or knock you to a wet floor.
I saw a patient holding a faulted hand-switch
and being shocked
by their foot touching their 'grounded' electric hospital bed.

"Stray voltage" can be dangerous, also,
when stepping from a pool of any type, yard sized or tub sized.
 
Ok the way I look at this is the following, Anytime you are around a body of water that has Electricity connected to it in any manner and you want someone to get in and out of it you are setting your self up for a shock. ( a potential difference between two voltages ) the reason that a bird can sit on a wire is because it never touches two different wires at the same time. So what you are doing is connecting all the surfaces together to make it in fact one wire so that as you get in or out of the water or you reach out of the pool or hot tub you never touch a different wire :)
 
LawnGuy,


LawnGuy,

Speaking of Stray Voltage did you see the Violation photo by Joe Tedesco,
the one of the "Floating Receptical"?

If memory is right, he was visiting a HO, and found him in the pool relaxing and watching a television.
He was floating on a air mattress,
with the television sitting on his tummy,
with the television plugged into a Floating Receptical
(see attached photo).

Having done testing in a hospital environment,
I assure you that a little "Stray Voltage" can kill a heart pace-maker,
or knock you to a wet floor.
I saw a patient holding a faulted hand-switch
and being shocked
by their foot touching their 'grounded' electric hospital bed.

"Stray voltage" can be dangerous, also,
when stepping from a pool of any type, yard sized or tub sized.

I'm not going to disagree with you. Just point out that the equipotential grid will equalize all stray voltage. It won't eliminate it.

IMHO the code and the UL need to get together on this and propose something that's REALLY safe, like all outdoor pool / spa/ fountain/ pond/ lighting equipment be double insulated, and receptacles, pool panels, spas, hottubs, etc, be fed from isolation transformers with NO reference to ground.
 
I know of a outdoor hot tub that is going on an existing concrete slab. How would any of you satisfy 680.26?
My guess is that it would not be code compliant to install a tub on an existing slab unless there just happened to be EPB below the subgrade.
 
Hot tub wiring and bonding

My guess is that it would not be code compliant to install a tub on an existing slab unless there just happened to be EPB below the subgrade.

My thoughts also,happy to have someone agree with me. Thanks for the response.
 
My thoughts also,happy to have someone agree with me. Thanks for the response.

I will agree with you as well.:)

There is no exception in Article 680 that an existing slab need not comply with the bonding requirements in 680.26.

Chris
 
I would agree with Dennis, Romeo & Chris on this.

An outdoor hot tub that is going on an existing concrete slab it is subject to the requirements of Section 680.26.

In my opinion:
Section 680.26 would apply regardless of whether this were going to be a self contained, package or field installed spa, or hot tub.


As Chirs noted: ?There is no exception in Article 680 that an existing slab need not comply with the bonding requirements in 680.26.?

mweaver
 
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