Do you need a bonding grid around a hot tub?

Status
Not open for further replies.

electricmanscott

Senior Member
Location
Boston, MA
If I filed under the 2008 code am I going to trench down 4" - 6" and lay in a # 8 solid wire all the way around the tub ? In either case, if you gave a price to do the job would you get it knowing that you had to install the grid (labor and material)?

.

Answer to question 1- Yes

#2 You could apply that logic to any job you bid. If you don't know the code requirements for something you are bidding you are sure to come up on the loosing end at the end of the game.
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
As far as the grid being required under grass or soil it is 100% clear, it must have the grid. There is no gray area, the only unclear part is what happens when there is a wood deck.

What does 'unpaved surface' mean to you?:-?
Bob,

I'm in agreement with the definition of "unpaved surfaces" but please bear with me. I'm not trying to be argumentative here. I guess the problem I'm having with all this is that we're all assuming that we know and are able to pre-plan where a packaged spa tub is going to be installed. In a new installation, where none of the landscaping has been done or patios installed, we make the provisions for and install the EPBG, we set the tub down, make the proper electrical connections, fill the tub with water and off we go. We meet the Code requirements and everyone's happy.

Looking back at the OP "It would be sitting on either dirt, or concrete", and not taking the possibility of any pre-existing conditions into account, if we look at this by your (and several others) interpretation of 680.26, you believe the NEC firmly states (or infers) that unless you plan to dig up the sod around the tub and install the EPBG or break up the concrete patio and install the EPBG don't bother setting the tub down here. I'm sorry, but I'm not one who drinks the Kool-ade just because the NEC says so. If I think there's something wrong with the way a code section is written I'm going to stop and ask questions first before I take a drink and swallow.;) I don't think this code section allows for any pre-existing conditions and needs to be revisited by the CMP. By the same token I'm not so smug as to believe I can boldly perform an installation of this type and pass an inspection without first clearing it with the State of NJ DCA and the local AHJ, but I think my argument is a valid one.

As far as wooden, Trex or Timber-Tech decking goes I still say that it not considered a conductive material irrespective of whether it's laying on soil or up on posts. Once you add water (rain or otherwise) to the mix I suppose you can make the argument that any material is conductive when wet when, in fact, it's the water or moisture content that would make current flow.

As usual, it's always fun going head to head with you and the others here in the forum. We got a lot of good responses and opinions on this topic.

Regards,

Phil
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Phil, why woud the hazrad be any less on an existing situation.
If a equipotential grid is needed on a new install would it not be needed on a retrofit ?
 

iwire

Moderator
Staff member
Location
Massachusetts
Bob,

I'm in agreement with the definition of "unpaved surfaces" but please bear with me. I'm not trying to be argumentative here.

No problem and I don't think you are being argumentative. :smile:


if we look at this by your (and several others) interpretation of 680.26, you believe the NEC firmly states (or infers) that unless you plan to dig up the sod around the tub and install the EPBG or break up the concrete patio and install the EPBG don't bother setting the tub down here.

That is exactly what is required.

Lets say they want their hot tub in the middle of the lawn on the grass.

Would you have to dig up the grass to get your feeder in or would you just lay it on top because it is existing grass?

Not try to be a jerk here but it is just that simple, the NEC does not care that it is difficult and the rules do not change for this application based on new or existing.


If I think there's something wrong with the way a code section is written I'm going to stop and ask questions first before I take a drink and swallow.;)

The idea is to ensure that the surface someone could stand on in bare feet while also touch the water is at the same potential as the water, the bonding is needed to do this.


I don't think this code section allows for any pre-existing conditions and needs to be revisited by the CMP.

Why is the danger less for an existing condition?

I agree this ends up being 'sticker shock' for the customer as they think they just paid 5K for a hot tub and thought it would cost $50.00 to wire it up.


By the same token I'm not so smug as to believe I can boldly perform an installation of this type and pass an inspection without first clearing it with the State of NJ DCA and the local AHJ, but I think my argument is a valid one.

I respectfully and strongly disagree, there is a real safety issue here that is the same for new or old installations.

As far as wooden, Trex or Timber-Tech decking goes I still say that it not considered a conductive material irrespective of whether it's laying on soil or up on posts.

I never said it was, what I have said is as the section is written any permit surface with 3' of the pool is required to be bonded. I don't know how you would bond wood.

But lets stay on the dirt and grass for now ........ there is no question existing grass needs to be treated like old grass.
 
Last edited:

mivey

Senior Member
...or would you just lay it on top because it is existing grass?...
:grin:
I don't know how you would bond wood.
At first I though of a nail plate. Now I'm thinking lag bolts or through-bolts with spring washers and a one-hole terminal. I guess you would have pepper the deck with lag bolts to ensure an equipotential plane between planks.

Probably easier to outlaw wood decks.
 

zappy

Senior Member
Location
CA.
How is the water bonded in a hot tub? And what if the wood was treated with tompson's water seal, then the water would bead and wouldn't be a continous path. I got a lot of good laughs from this topic, and so good info too.
 
Last edited:

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I did a quick test on my deck (no hot tub). It is 2x6 deck on 2x8 joists with brass screws holding the deck to the joists. It rained a bit about 24 hours ago, but today was warm and sunny.
deckdry.jpg

dryresistance.jpg

wetresistance.jpg

I did not let the water really soak in before I ran the "wet test". The megger leads are connected to the brass screws.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
How is the water bonded in a hot tub? And what if the wood was treated with tompson's water seal, then the water would bead and wouldn't be a continous path. I got a lot of good laughs from this topic, and so good info too.


The water can be bonded in a few ways. Sometimes all it takes is 9"sq. of copper piping in the recirculating line. Also any light in the tub would also be enough to bond the water.

Thompson water seal will not last very long and there is no guarantee the HO will keep it up.
 

M. D.

Senior Member
I did not let the water really soak in before I ran the "wet test". The megger leads are connected to the brass screws.


:smile:Brass screws?... brass screws ??? well ,.. according to the "all metal parts folks" those srews within 5' would require bonding as well:) ,....Good Grief

I would not bond the wood,.. or the screws
 
Last edited:
Status
Not open for further replies.
Top