hot tub equipotential

[iwire]

.
YES! I am working from a 2005 NEC CD on board my computer

It was a just a question not an insult.

I don't know where you are from or what code cycle is being used in your area, some areas are still using 2002 or even 1999 NEC.

There where a lot of changes between the 2002 and 2005 I was wondering if this might be the cause of our disagreement.

 

[infinity]

Sounds like the disagreement is whether or not a hot tub sitting on a concrete patio is permanently installed or not. Gmack's contention is that it isn't and therefore equipotential bonding isn't required.

 

[iwire]

Sounds like the disagreement is whether or not a hot tub sitting on a concrete patio is permanently installed or not. Gmack's contention is that it isn't and therefore equipotential bonding isn't required.

Trevor I agree with your take on the disagreement.

What I don't see is separate rules in the NEC for permanent or temporary Hot tubs.

 

[bphgravity]

680.26 positively applies to ALL outdoor spas and hottubs. I just completed my 75th hour of continuing education this past week with over half the hours directly related to the NEC or electrical industry. This very issue was brought up at nearly every seminar and course I have attended this year. There is no doubt as to the intent of the Article...

 

[Pierre C Belarge]

Anger clouds one's mind and makes it difficult to make proper decisions, take the emotion out of the equation and listen to what some of the others here are presenting.
By the way: Bryan and I are both AHJs.. what kind of AHJ are you refering to when you say let an AHJ speak up? Also, both Bryan and I have just had seminars/classes which discussed this and you seem to be ignoring these facts/comments.

I won't comment anymore, as discussing a topic with someone who does not listen is a waste of time.

 

[petersonra]

Trevor I agree with your take on the disagreement.

What I don't see is separate rules in the NEC for permanent or temporary Hot tubs.

I think the argument would be that the NEC generally only applies to premises wiring and would not apply to a portable device that is not permanently installed. I think it is a good argument since the pool and spa sections don't specifically state otherwise.

My wife has a blow up pool, maybe 5 feet in diameter and 8 or 10 inches tall. She blows it up and fills it up with water now and then when her nieces and nephews visit so they can splash in the water. Does it require an equipotential grid?

 

[iwire]

I think it is a good argument since the pool and spa sections don't specifically state otherwise.

Actually they do.

III. Storable Pools
680.30 General.
Electrical installations at storable pools shall comply with the provisions of Part I and Part III of this article.

Storable Swimming or Wading Pool. Those that are constructed on or above the ground and are capable of holding water to a maximum depth of 1.0 m (42 in.), or a pool with nonmetallic, molded polymeric walls or inflatable fabric walls regardless of dimension.

My wife has a blow up pool, maybe 5 feet in diameter and 8 or 10 inches tall. She blows it up and fills it up with water now and then when her nieces and nephews visit so they can splash in the water. Does it require an equipotential grid?

No, it does not need a grid but if it also has electrical components as some storable pools do the NEC does apply to it.

However we are not talking about pools storable or permanent, we are talking about hot tubs installed outside and they must follow the rules for permanent pools.

 

[George Stolz]

Let one AHJ stand up here and say it is NEC 2005.

Gmack, I don't know what to say to bring you around.

So far, three inspectors on this thread alone have stated either directly (Bryan Holland, post #44, and Pierre Belarge, post #35) or indirectly (rcarroll, post #2) that an equipotential bonding grid is required on hot tubs. Mike Holt believes so as well, by the article that you posted. Don has been in the trade over 30 years, Bob for over 20, Trevor for over 20, and they all agree that 680.42 requires an equipotential bonding grid be installed according to 680.26's specifications.

I understand it may be extremely difficult to overcome the idea that somehow you've passed hundreds without one; but that doesn't make it legal. That doesn't make you a bad electrician - I hear about something else at least once a month from hanging out here that I was trained to do that was either illegal or just plain dumb. I learn and move on.

You seem hung up on hot tubs being permanent or temporary. I have this to say about it. The code is silent on it, a hot tub is a hot tub. If you have evidence to the contrary, produce it.

The other thing I have to say about the "temporary" hot tub, is how many people do you know of that have hot tubs they move around the yard? Realistically, I know of noone who drains their tub or leaves wheels on it, that they can soak in the front yard if they feel like it. Generally, a hot tub does not have to be anchored to the concrete to be there permanently. Just add water.

I share Pierre's frustration. If you cannot reason, we cannot discuss. You have to give us something to work with to maintain a discussion.

 

[Minuteman]

We have installed over 30 Hot tubs this year. We work in several jurisdictions, each on different code cycles. We have never installed a grid for a hot tub.

The latest tub that we installed was in a jurisdiction that is in the '05 cycle. I SPECIFICALLY asked the Chief inspector (who, by the way is employed by the AHJ - the city -and is not himself the AHJ). It is their take that they may require a grid at a future date, but that it is not necessary, as a tub set upon the concrete and not in the dirt. However, I could install a grid if I so choose.

 

[dingokangaroo]

Gmack, I don't know what to say to bring you around.

So far, three inspectors on this thread alone have stated either directly (Bryan Holland, post #44, and Pierre Belarge, post #35) or indirectly (rcarroll, post #2) that an equipotential bonding grid is required on hot tubs. Mike Holt believes so as well, by the article that you posted. Don has been in the trade over 30 years, Bob for over 20, Trevor for over 20, and they all agree that 680.42 requires an equipotential bonding grid be installed according to 680.26's specifications.

I've been in for 23yrs now and I must agree. sorry Gmack. code is code

 

[ryan_618]

I also agree that outdoor hottubs need the grid. 680.42(B) is very, very clear on this.

 

[Cavie]

Now that we know it would need a grid, How would this grid be installed on an existing slab? I have not run into this as we a using the 2002 code.

 

[Minuteman]

Cavie, that's a good question. I would guess I would have to bust up the concrete and start over.

If I understood Iwire correctly, the HO could just build a wood deck above the existing concrete.

Could be interesting.

 

[George Stolz]

Now that we know it would need a grid, How would this grid be installed on an existing slab? I have not run into this as we a using the 2002 code.

Chisel in an find some rebar, I suppose.

Cavie, IMO, in the 2002, bonding to existing rebar in the deck of a pool or spa was required. See 680.42 and 680.26. In the 2005, alternative means were provided for constructing an equipotential bonding grid (680.26(C)(3)); however, some undefined method was still required in 2002:

680.26(B)(1)(1) Metallic Structural Components. All metallic parts of the pool structure, including the reinforcing metal of the pool shell, coping stones, and deck, shall be bonded. The usual steel tie wires shall be considered suitable for bonding the reinforcing steel together, and welding or special clamping shall not be required. These tie wires shall be made tight. If reinforcing steel is effectively insulated by an encapsulating nonconductive compound at the time of manufacture and installation, it shall not be required to be bonded. Where reinforcing steel is encapsulated with a non-conductive compound, provisions shall be made for an alternate means to eliminate voltage gradients that would otherwise be provided by unencapsulated, bonded reinforcing steel.

680.26(C) in 2002:

(C) Common Bonding Grid. The parts specified in 680.26(B) shall be connected to a common bonding grid with a solid copper conductor, insulated, covered, or bare, not smaller than 8 AWG. Connection shall be made by exothermic welding or by pressure connectors or clamps that are labeled as being suitable for the purpose and are of stainless steel, brass, copper, or copper alloy. The common bonding grid shall be permitted to be any of the following:
(1) The structural reinforcing steel of a concrete pool where the reinforcing rods are bonded together by the usual steel tie wires or the equivalent
(2) The wall of a bolted or welded metal pool
(3) A solid copper conductor, insulated, covered, or bare, not smaller than 8 AWG
(4) Rigid metal conduit or intermediate metal conduit of brass or other identified corrosion-resistant metal conduit

IMO, I believe 2002's 680.26(C)(3) became the extended, explained 680.26(C)(3) in 2005:

(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 common bonding grid shall extend 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:
(1) Structural Reinforcing Steel. The structural reinforcing steel of a concrete pool where the reinforcing rods are bonded together by the usual steel tie wires or the equivalent
(2) Bolted or Welded Metal Pools. The wall of a bolted or welded metal pool
(3) Alternate Means. This system shall be permitted to be constructed as specified in (a) through (c):
a. Materials and Connections. The grid shall be constructed of minimum 8 AWG bare solid copper conductors. Conductors shall be bonded to each other at all points of crossing. Connections shall be made as required by 680.26(D).
b. Grid Structure. The equipotential bonding grid shall cover the contour of the pool and the pool deck extending 1 m (3 ft)horizontally from the inside walls of the pool. The equipotential bonding grid shall be arranged in a 300 mm (12 in.) by 300 mm (12 in.) network of conductors in a uniformly spaced perpendicular grid pattern with tolerance of 100 mm (4 in.).
c. Securing. The below-grade grid shall be secured within or under the pool and deck media.

Don't get too cozy, more text changes to clarify are forthcoming in 2008.

Edit to add: I forgot to mention, there was actually a TIA to modify this section a bit to the 2005, a search will produce it, just a sec and I'll edit in a link...

Scroll down to Post #4 of this thread for the TIA.

 

[Minuteman]

Chisel in an find some rebar, I suppose.

Edit to add: I forgot to mention, there was actually a TIA to modify this section a bit to the 2005, a search will produce it, just a sec and I'll edit in a link...

Scroll down to Post #4 of this thread for the TIA.

George, I don't see how chiseling down to a rebar is going to conform to the contours of the pool.

1. Revise 680.26 (C) & 680.26 (C)(1) as follows:
(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.

The vinyl lined polymer wall, fiberglass composite, or other pools constructed of nonconductive materials pretty much describes the hottubs we install.

 

[George Stolz]

That would relieve us of installing the grid in the walls of the tub, but what about the deck? It's required to be bonded outwards from the pool/spa for three feet surrounding the pool, I believe.

The area immediately under the spa would serve no purpose to bond, I wouldn't think. But the area surrounding the spa would see use, in bare wet feet walking on it, IMO.

 

[infinity]

Chisel in an find some rebar, I suppose.

Cavie, IMO, in the 2002, bonding to existing rebar in the deck of a pool or spa was required. See 680.42 and 680.26. In the 2005, alternative means were provided for constructing an equipotential bonding grid (680.26(C)(3)); however, some undefined method was still required in 2002:

This makes the assumption that all concrete decks or patios have rebar. Having broken a few old ones up over the years I know that they don't. Some do, some don't. Sounds like the days of buying a hot tub from big orange and plopping it down on the old concrete are over. Somewhere in the equation should be the thought of spending additional money to install the E-grid, even if it means a new concrete deck.

 

[Minuteman]

Yeah, well - I'm waiting to see if "Mr. Electric" and the boys from NECA start putting in E-grids first.

 

[iwire]

Yeah, well - I'm waiting to see if "Mr. Electric" and the boys from NECA start putting in E-grids first.

Your choice....I think it's a poor one.

The NEC currently requires the grid at least around the perimeter.

The fact it is not being enforced is not going to save your bacon if an accident happens.

A couple of ways to avoid chopping up an existing slab.

1) Pour a new slab on top of the old with the grid installed.

2)Build a deck out of non-conductive material, it does not have to be a tall deck.

 

[Minuteman]

Build a deck out of non-conductive material, it does not have to be a tall deck.

That's probably going to be the best way. I know 3-4 good carpenters to recommend.