Outdoor Spa Grounding

[jeff43222]

I remember hearing something about there being new grounding requirements for outdoor spas with the 2005 code cycle, which is now law here. I was just hired to wire one that is to be put outdoors on an existing concrete pad. Do I need to do anything more with the grounding other than make sure everything in the spa is bonded and that an EGC makes its way back to the panel?

I looked through 680 and 250, but I didn't find anything that looked different from the 2002 version.

 

[jwelectric]

Re: Outdoor Spa Grounding

Here is an answer that I received from the DOI in North Carolina concering the same installation of a hot tub.

Mike, 680.26(C) would apply to a new installation of a hot tub outdoors. The paved walking deck 3' out from the tub would need the equipotential bonding grid to be installed per the NEC. On existing paved areas where a hot tub is installed, this is a new installation of the tub, so the equipotential bonding grid would have to be installed or a non paved walking surface could be installed then 680.26(C) would not apply.
I hope this will clarify any questions that you may have.
Thanks
Mitchell Bryant
Chief Asst. Electrical Inspector
322 Chapanoke Rd. Suite 200
Raleigh, NC 27603-3400

 

[jeff43222]

Re: Outdoor Spa Grounding

I looked through 680.26(C) in the 2005 NEC. Based on it, and what the inspector told you, it seems to me that this hot tub installation is going to be a big headache.

The location I looked at yesterday was on a stone/concrete patio immediately outside the back door, which is at the bottom of a set of steps that goes below grade. The steps up to the patio are contiguous with the patio, and that's where they plan on placing the hot tub.

I'm still a little confused on one point, though. 680.26(C) says that all parts in 680.26(B) must be connected to an equipotential bonding grid. But the inspector seemed to indicate that as long as the walking surfaces are not paved, 680.26(C) doesn't apply. I don't see anything that says that in 680.26(C). My reading of that section makes me think that the bonding grid as described in 680.26(C)(3) is required under the hot tub regardless of paved/unpaved status, and it only has to extend beyond the contour of the pool (for 3') if it's a paved walking surface.

I suspect the homeowners aren't all that keen on breaking up their patio so I can install an equipotential bonding grid.

 

[jwelectric]

Re: Outdoor Spa Grounding

I solved the problem by having a walk way built around the tub out of pressure treated boards.

My neighbor has used a plastic type of substance around his to comply.

I bought a permit to remodel my home 20 years ago and keep calling for a consultation every couple of months to keep the permit active just in case I decide to do any work I will be covered under the ?84 or was that an earlier cycle of the code.

 

[LarryFine]

Re: Outdoor Spa Grounding

Originally posted by jwelectric:
...I will be covered under the ?84 or was that an earlier cycle of the code.

I'd love to be a fly on the wall during your next inspection!

 

[jwelectric]

Re: Outdoor Spa Grounding

A true story.

I just got the final and the CO on a room addition to our house that I bought the permit in November of 2000. When the inspectors came all three of them gathered in the back yard for a conference that lasted for about 45 minutes. Two of them left and the poor old electrical (cross trained) was left to do it all by himself.

To keep this story short I will only say that after him asking me more questions than a Grand Jury he gave me the final. Together we figured that there had been nine different people to look at this work and three of them had retired.

He ask me at least fifteen times had we been sleeping in this room. I kept changing the subject until he picked up the alarm clock and pointed out that he need to get going.
A bit of advice to any of you who are doing work on your house, if you have been holding the permit for a few years before calling in the final it is a good idea to remove your razor, tooth brush and such other personal items from the new bathroom. They are a dead giveaway.

 

[LawnGuyLandSparky]

Re: Outdoor Spa Grounding

Originally posted by jwelectric:
A true story.

I kept changing the subject until he picked up the alarm clock and pointed out that he need to get going.
A bit of advice to any of you who are doing work on your house, if you have been holding the permit for a few years before calling in the final it is a good idea to remove your razor, tooth brush and such other personal items from the new bathroom. They are a dead giveaway.

Brilliant!

 

[jeff43222]

Re: Outdoor Spa Grounding

The plot thickens. I just got off the phone with the state inspector who will be inspecting the job, and he said that as far as he was concerned, the equipotential grid was only required for an in-ground pool, not a self-contained unit sitting on a slab. To me, that makes sense, as I have a hard time understanding how there would be a problem with underground voltage gradients caused by a self-contained unit sitting above the ground.

He told me he would research the issue and call me back with a more definitive answer.

 

[iwire]

Re: Outdoor Spa Grounding

Originally posted by jeff43222:
To me, that makes sense, as I have a hard time understanding how there would be a problem with underground voltage gradients caused by a self-contained unit sitting above the ground.

Jeff I disagree I do not see how the need would change for an in ground as opposed to tub on the surface.

What if you are standing on the deck and touch a metal part of the bonding system that for whatever reason has a potential above that of 'earth' ground?

IMO the purpose of that grid in the deck would be to insure that the deck is at the same potential as the entire bonding system. At any given moment that bonding system may have a potential between it and 'earth' or that unbonded deck.

 

[jeff43222]

Re: Outdoor Spa Grounding

The state inspector just called me back and told me what he expects. He said all I have to do is bond the metal parts as usual and that no bonding grid needs to be installed. He said that since the hot tub is a self-contained unit sitting above ground and insulated from the deck by the wood frame of the unit, there's really no need to worry about equipotential issues. He also said he wouldn't make me bust up the existing slab.

He did say that if we were going to do anything in-ground, then the grid would need to be installed.

 

[jwelectric]

Re: Outdoor Spa Grounding

Originally posted by jeff43222:
The state inspector just called me back and told me what he expects. He said all I have to do is bond the metal parts as usual and that no bonding grid needs to be installed. He said that since the hot tub is a self-contained unit sitting above ground and insulated from the deck by the wood frame of the unit, there's really no need to worry about equipotential issues. He also said he wouldn't make me bust up the existing slab.

He did say that if we were going to do anything in-ground, then the grid would need to be installed.

Your state inspectors is very badly mistaken

 

[jwelectric]

Re: Outdoor Spa Grounding

 

[jeff43222]

Re: Outdoor Spa Grounding

Originally posted by jwelectric:
Your state inspectors is very badly mistaken

I did point this section out to him while we were on the phone. Doesn't 680.42(B) seem to indicate that bonding all the metal parts together is sufficient, rather than requiring the bonding grid?

 

[iwire]

Re: Outdoor Spa Grounding

Great picture and I know I would feel better standing barefoot and wet on that wood deck than a cement deck.

Question do the barrel hoops need bonding?

 

[jeff43222]

Re: Outdoor Spa Grounding

NEC 680.42(B) "... The metal bands or hoops used to secure wooden staves shall not be required to be bonded as required in 680.26."

 

[iwire]

Re: Outdoor Spa Grounding

Originally posted by jeff43222:
NEC 680.42(B) "... The metal bands or hoops used to secure wooden staves shall not be required to be bonded as required in 680.26."

That is the one I was thinking of.

 

[jwelectric]

Re: Outdoor Spa Grounding

Originally posted by jeff43222:
I did point this section out to him while we were on the phone. Doesn't 680.42(B) seem to indicate that bonding all the metal parts together is sufficient, rather than requiring the bonding grid?

To each his own my friend but I do believe that you will find that the bonding of the metal for the staves of the tub and the difference of potential between the water and the concrete are two complete different things.

The danger of this hot tub will be when the person is exiting the tub where the water is in contact on one side of the person and the concrete is in contact with this person on the other side.

It won?t matter if this tub has passed an inspection or not if it does not comply with 680.26 (C) you will be liable, end of story.

In your original post you made mention of the concrete pad.

I was just hired to wire one that is to be put outdoors on an existing concrete pad. Do I need to do anything more with the grounding other than make sure everything in the spa is bonded and that an EGC makes its way back to the panel?

Now it is up to you weather you decide to comply with the requirements of the NEC or try to find a way of getting out of doing what is required. I have pointed out to you what is required by the NEC and should you choose to keep asking until you find some one that will agree that, ?it will be okay? is entirely up to you. Good luck.

 

[iwire]

Re: Outdoor Spa Grounding

Jeff I agree with Mike's post entirely.

Regardless of the inspectors blessing you are on the hook to follow the NEC.

If this went to court would the inspector 'remember' your conversation and even if he did would it help legally or morally?

 

[jeff43222]

Re: Outdoor Spa Grounding

I'm not trying to get out of anything, nor do I want to compromise safety. When I get differences of opinion in response to a question I ask, I tend to ask a lot more questions of more people, as that is usually how things get clearer for me.

When I talked to the inspector, he didn't seem quite as up on this aspect of the code as I would have expected. Usually when I ask an inspector about something, they know the answer cold and tell me what I need to do. I would tend to agree with you guys before I would go the route the inspector said I could take.

It sounds to me like you're saying the way to go is to make sure they install a 3' wood or plastic walkway surrounding the tub on all sides. According to the response Mike got from the NC state inspector, 680.26(C) would then not apply. Would you consider the installation safe and code-compliant if all the bonded parts are connected to the EGC? Or should I still install some kind of grid? If so, where?

I certainly don't want to have anyone get hurt as a result of any work I did, which is the main reason I posted the question in the first place. I want to be sure I follow the code, and this equipotential bonding grid requirement is new to me.

 

[ryan_618]

Re: Outdoor Spa Grounding

I also agree with Mike (and Bob). This deck needs to be bonded. I also think that Jeff has been offered some very good advice regarding the legal implications of what he is doing.

If I were to not bond the deck, I would get it in writing from the AHJ at the very least. Even then, I think I would still bond it.

By the way, I notice Jeff that you are referencing 680.26(C). Are you referencing the TIA that was put out on this section?

(C) Equipotential Bonding Grid. The parts specified in 680.26(B) shall be connected to an equipotential bonding grid with a solid copper conductor, insulated, covered, or bare, not smaller than 8 AWG or rigid metal conduit of brass or other identified corrosion-resistant metal conduit. Connection shall be made by exothermic welding or by listed pressure connectors or clamps that are labeled as being suitable for the purpose and are of stainless steel, brass, copper, or copper alloy. The equipotential bonding grid shall conform to the contours of the pool and shall extend within or under paved walking surfaces for 1 m (3 ft) horizontally beyond the inside walls of the pool and shall be permitted to be any of the following: Exception: The equipotential bonding grid shall not be required to be installed under the bottom of or vertically along the walls of vinyl lined polymer wall, fiberglass composite, or other pools constructed of nonconductive materials. Any metal parts of the pool, including metal structural supports, shall be bonded in accordance with 680.26(B). For the purposes of this section, poured concrete, pneumatically applied (sprayed) concrete, and concrete block, with painted or plastered coatings, shall be considered conductive material. (1) Structural Reinforcing Steel. The structural reinforcing steel of a concrete pool or deck where the reinforcing rods are bonded together by the usual steel tie wires or the equivalent. Where deck reinforcing steel is not an integral part of the pool, the deck reinforcing steel shall be bonded to other parts of the bonding grid using a minimum 8 AWG solid copper conductor. Connection shall be per 680.26(D).