Exterior packaged hot tub

[grasfulls]

Re: Exterior packaged hot tub

I did say a hot tub and this is exactly the way I am doing it Ronald, thanks!

 

[infinity]

Re: Exterior packaged hot tub

I have endeavored to read everything and got pretty turned around. I am now sticking with the 2002 code because the prints are stamped as such. relative to JW's post (a good one, thanks!)

I'd be less concerned as to what date stamp is on the prints and more concerned as to which code the jurisdiction that you're working in has adopted.

 

[grasfulls]

Re: Exterior packaged hot tub

The authority having jurisdiction is the one that stamped them at the time the permit was issued. This way they cannot adopt the 2005 before completion and mandate compliance. This particualr city could do just that. Good point though.

Palo Alto, California is one of the few cities this way thaat own their own utility and they have a tendency to be the first to adopt the latest codes, which is actually pretty nice.
Gary

[ August 06, 2005, 10:02 PM: Message edited by: grasfulls ]

 

[jwelectric]

Re: Exterior packaged hot tub

As is pointed out above the date stamped on the print has no bearing as to which code cycle you are under.

Weather concrete, brick, block or tile is in contact with the earth or not has no bearing on the difference of potential between the water in the tub and the tile under the tub. This bonding grid is to assure that there can be no difference between the two.

The fact that this tub is on the second floor does not change the requirement for the equipotential bonding grid.


Edited to add:

We are bonding the tub to the grid, we are not grounding the grid to the earth as is implied by the earth contact


[ August 06, 2005, 10:02 PM: Message edited by: jwelectric ]

 

[ronaldrc]

Re: Exterior packaged hot tub

I thought bonding was to create a good connection between conduit and equipment to clear faults not as personnel protection.

I thought thats what the GFI was for.

 

[grasfulls]

Re: Exterior packaged hot tub

Hi JW,
The tub cannot be bonded to the grid, it is wood and foam. The tub motor will have an equipment ground on it, so adding a grid under the tub embedded in the thinset (typically only about an 1/8 to 1/4" thick, they would have to modify the setting for a grid to fit, I guess)then landed on the....motor (I see that in an earlier post)? How is it the tile can have a potential relative to the water? I can see it in pools and other at or below grade items.

We are bonding the tub to the grid, we are not grounding the grid to the earth as is implied by the earth contact

When you posted landing this grid on the motor and the motor must have an equipment ground, then in essence I would be bonding the grid to ground via the equipment ground path back to the service.

If the finish floor is ceramic tile then you will need to install an equipotential bonding grid as outlined in 680.26 (C)(3). This grid will bond to the pump motor with a #8.

Honest JW, If I can clearly see the "potential" (tongue in cheek) for a potential between tile having no connection to ground or any electrical source and the water that may have connection to an electrical source if a problem develops, to exist in this case, I will go to the City and ask for their understanding. I will just have to hope they do not tell the GC I went behind his back. I believe if I approached the GC he will say NO WAY and then I would be forced to go to the City because this would then be a life safety issue and he would know I did. I do a LOT of work for this GC.

gary

[ August 06, 2005, 10:14 PM: Message edited by: grasfulls ]

 

[ronaldrc]

Re: Exterior packaged hot tub

If you intentionally install a grid your just adding a shock hazard.Are you not?

 

[grasfulls]

Re: Exterior packaged hot tub

Hi Ronald,

I thought bonding was to create a good connection between conduit and equipment to clear faults not as personnel protection.

I thought thats what the GFI was for.

We are discussing a different type of bonding required....well..... required in a lot of different scenarios, I am just not sure of this particular scenario.

bonding system with the sole function of establishing equal electrical potential (voltage) in the vicinity of the swimming pool.

In fact, from the 2002 handbook:

680.26 Bonding.
(A) Performance. The bonding required by this section shall be installed to eliminate voltage gradients in the pool area as prescribed.
FPN:This section does not require that the 8 AWG or larger solid copper bonding conductor be extended or attached to any remote panelboard, service equipment, or any electrode.
The primary purpose of bonding is to ensure that voltage gradients in the pool area are eliminated. The fine print note explains that the 8 AWG conductor's only function is to eliminate the voltage gradient in the pool area. It is not required to provide a path for fault current that may occur as a result of electrical equipment failure. See Exhibit 680.10.

[ August 06, 2005, 11:13 PM: Message edited by: grasfulls ]

 

[ronaldrc]

Re: Exterior packaged hot tub

Where talking about a hot tub not a swimming pool big difference.

 

[grasfulls]

Re: Exterior packaged hot tub

This is an interesting thought Ronald,

If you intentionally install a grid your just adding a shock hazard.Are you not?

.

If the tile is not grounded, and I do not think it is, and I install a grid and connect it to the motor, I will now be "grounding" the tile. In a situation where the tile is set on pavement at grade, it is already grounded and a potential variant could exist between the water and the tile. By putting a grid in that bonds all of the non-equipment metal parts together, metal parts often in contact with the water, we equalize the potential. I clearly see the need for this, but not here.


I think my head just imploded.

[ August 06, 2005, 11:14 PM: Message edited by: grasfulls ]

 

[jwelectric]

Re: Exterior packaged hot tub

How you work this out with the general contractor may mean the difference between someone getting hurt and not.

The water in the hot tub will be traveling across the heating element that will be energized by electrical current. The tile and thin set that will be under the tub is conductive. It is necessary to have both of these at the same potential. This is achieved with the bonding grid as has been outlined to you.

Remember that a slight tingle could be enough to cause some one to fall back in the tub and drown. Could be enough to cause some to slip and fall hitting their head and, well I hope that you see that electrocution is not the only way to be hurt or killed.

 

[ronaldrc]

Re: Exterior packaged hot tub

Grounding is taking an electrical system to the earth.

Bonding means to ensure a good electrical connection between parts. Or we can just make it as complicated as possible like it happens on here more often than not.

[ August 07, 2005, 12:38 AM: Message edited by: ronaldrc ]

 

[grasfulls]

Re: Exterior packaged hot tub

Hi Ronald (again),
Actually, these guys have made me read the code a little more thoroughly than I have in the past (not a good point relative to my typical study habits) and the code almost forces treating them the same way.

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.

Part II is permanently installed pools.

gary

[ August 06, 2005, 10:41 PM: Message edited by: grasfulls ]

 

[jwelectric]

Re: Exterior packaged hot tub

Originally posted by ronaldrc:
Grounding is taking an electrical system the the earth.

Bonding means to ensure a good electrical connection between parts. Or we can just make it as complicated as possible like it happens on here more often than not.

As you have said here, could there be any difference in potential between to of the items bonded in the bonding that you are talking about above?

 

[grasfulls]

Re: Exterior packaged hot tub

Well JW,
This makes a lot of sense:

How you work this out with the general contractor may mean the difference between someone getting hurt and not.

The water in the hot tub will be traveling across the heating element that will be energized by electrical current. The tile and thin set that will be under the tub is conductive. It is necessary to have both of these at the same potential. This is achieved with the bonding grid as has been outlined to you.

Remember that a slight tingle could be enough to cause some one to fall back in the tub and drown. Could be enough to cause some to slip and fall hitting their head and, well I hope that you see that electrocution is not the only way to be hurt or killed.

Should some one get hurt it will be you that will be held responsible not the general contractor.

I will attempt to figure out a way to broach the subject and keep everyone happy, even the homeowner who will have to pay for it.

I will post sometime next week with the results, i.e, the city's perspective, etc.

I appreciate your persistence.

gary

 

[jwelectric]

Re: Exterior packaged hot tub

I would appreciate this and if you don?t mind, would you send me a PM telling me which city and state.

Good luck with this job. I got stuck on a tub and the grid. Had to install a wooden floor in order to get it to pass. This came out of my pocket.

 

[electricmanscott]

Re: Exterior packaged hot tub

Sometimes persistence pays off. I agree with the need for the bonding grid and am glad to see that Gary has come around to agree as well.