Hot tub

[Dennis Alwon]

Necessary or not the code requires that a hot tub installed outside conform with the requirements of Part II
680.42 Outdoor Installations.
A spa or hot tub installed outdoors shall comply with the provisions of Parts I and II of this article, except as permitted in 680.42(A) and (B), that would otherwise apply to pools installed outdoors.

680.26 is in Part II therefore part of the installation of a hot tub installed outside.

I agree but I don't see where a deck applies to the requirements. It takes of conductive surfaces- paved, etc. I just don't read 680.26 as applying to a wood deck.

 

[Dennis Alwon]

What would you do? Would you lay a copper grid or other grid down on the deck and have to walk on it.

 

[jwelectric]

Let?s look and see what it does say,

680.26 Equipotential Bonding.

(A) Performance. The equipotential bonding required by this section shall be installed to reduce voltage gradients in the pool area.

(B) Bonded Parts. The parts specified in 680.26(B)(1) through (B)(7) shall be bonded together using solid copper conductors, insulated covered, or bare, not smaller than 8 AWG or with rigid metal conduit of brass or other identified corrosion-resistant metal. Connections to bonded parts shall be made in accordance with 250.8. An 8 AWG or larger solid copper bonding conductor provided to reduce voltage gradients in the pool area shall not be required to be extended or attached to remote panelboards, service equipment, or electrodes.

(2) Perimeter Surfaces. The perimeter surface shall extend for 1 m (3 ft) horizontally beyond the inside walls of the pool and shall include unpaved surfaces as well as poured concrete and other types of paving. Bonding to perimeter surfaces shall be provided as specified in 680.26(B)(2)(a) or (2)(b) and shall be attached to the pool reinforcing steel or copper conductor grid at a minimum of four (4) points uniformly spaced around the perimeter of the pool. For nonconductive pool shells, bonding at four points shall not be required.
(a) Structural Reinforcing Steel. Structural reinforcing steel shall be bonded in accordance with 680.26(B)(1)(a).
(b) Alternate Means. Where structural reinforcing steel is not available or is encapsulated in a nonconductive compound, a copper conductor(s) shall be utilized where the following requirements are met:
(1) At least one minimum 8 AWG bare solid copper conductor shall be provided.
(2) The conductors shall follow the contour of the perimeter surface.
(3) Only listed splices shall be permitted.
(4) The required conductor shall be 450 to 600 mm (18 to 24 in.) from the inside walls of the pool.
(5) The required conductor shall be secured within or under the perimeter surface 100 mm to 150 mm (4 in. to 6 in.) below the subgrade.

Don?t much matter how one goes about accomplishing this requirement as long as the requirement gets fulfilled.

 

[Dennis Alwon]

Let?s look and see what it does say,



Don?t much matter how one goes about accomplishing this requirement as long as the requirement gets fulfilled.

You are correct the statement says what it says but I don't believe they are meaning to include decks. I infer from the info that it pertains to tubs or pools in dirct contact with the earth in some fashion. I cannot believe for one minute that a grid would be needed on a deck. It ain't gonna happen.

So under alternate means it says 4 to 5 inches below grade. Sitting on a deck the equipotental grid would do absolutely nothing below grade under the deck. How could this possibly be required. I still say it is not necessary.

 

[jwelectric]

Not below grade but below subgrade.

I would suppose that if the tub was on a deck then the grid would need to be secured to the underside of the deck. The purpose of the grid is to reduce voltage gradients in the pool or this case tub area.
I also suppose that it is possible to have voltage gradients between the tub water which by the way will need to be bonded, 680.26(C), and the wet wood of the deck.

 

[Dennis Alwon]

Not below grade but below subgrade.

I would suppose that if the tub was on a deck then the grid would need to be secured to the underside of the deck. The purpose of the grid is to reduce voltage gradients in the pool or this case tub area.
I also suppose that it is possible to have voltage gradients between the tub water which by the way will need to be bonded, 680.26(C), and the wet wood of the deck.

So if you attach the grid to the 2x4 decking it will only be 1 1/2" below sub grade. If you attach lower than it doesn't touch the deck. Something is amiss here.

I hear you but..

 

[jwelectric]

So if you attach the grid to the 2x4 decking it will only be 1 1/2" below sub grade. If you attach lower than it doesn't touch the deck. Something is amiss here.

I hear you but..

(5) The required conductor shall be secured within or under the perimeter surface 100 mm to 150 mm (4 in. to 6 in.) below the subgrade.

It don't say that it has to be 4 inches below but it can be part of as it would be if attached to the underside of the decking.
Don't forget to bond the water.