680.40 Hot Tub

[Greg1707]

I need some help with installing a 2 person self contained hot tub. The unit will be sitting very close to the house and there is not much space. I have attached a photo. The hot tub will sit in the area where you see the ice chest. The hot tub will be installed on a gravel base. There are brick pavers surrounding the area. I intend to move the A/C disconnect to a new location away from the hot tub. I would like to run RNMC along the wall of the house and ON the ground to the GFCI disconnect for the hot tub. I would also like to run the A/C power on the ground in RNMC. 680.10 prohibits underground wiring with 5 feet horizontally unless installed in race way and buried. Does 680.10 prohibit using a raceway on top of the ground? Finally, I understand I will need to bond the vents, window frame and water pipe together. Finally, does 680.26, equipotential bonding, require that I install a grid in the gravel base and extend it 3 feet horizontally?
I apologize for these questions but I don't have a lot experience with 680.

 

[Dennis Alwon]

Yes, you do need to install a grid or something depending if you are on the 05 or 08 code. I am one of the followers who believe that bonding the window frame is not necessary and IMO, ridiculous.

 

[augie47]

Yes, you do need to install a grid or something depending if you are on the 05 or 08 code. I am one of the followers who believe that bonding the window frame is not necessary and IMO, ridiculous.

But there is, apparenty, another point of view. The attached graphic is from Mike's guidline to Art 680.

Possibly from the wording of 680.16(B)(7).

(7) Metal Wiring Methods and Equipment. Metal-sheathed cables and raceways, metal piping, and all fixed metal parts shall be bonded.




View attachment 4003

 

[Dennis Alwon]

But there is, apparenty, another point of view. The attached graphic is from Mike's guidline to Art 680.

Possibly from the wording of 680.16(B)(7).

(7) Metal Wiring Methods and Equipment. Metal-sheathed cables and raceways, metal piping, and all fixed metal parts shall be bonded.




View attachment 4003

I heard that graphic was modified or changed in the latest book. True????

 

[augie47]

You may be right. That was the latest reference I had. I will search further.
(The date is 2004 on the website graphic)

 

[Greg1707]

bonding grid

bonding grid

Thanks for the replies to my question. Ok, so the spa is self contained unit. I need to bury a #8 bare copper wire around the perimeter of the spa and connect it at four points to some where on the bottom of the spa? And also bond any metal nearby. Is that it?

BTW, why is it that not a single website that is DIY or spa manufacturer related mentions anything about bonding grids etc? How can they fail to mention this? The information available covers most of the other issues but not this.

 

[Greg1707]

Equipotential bonding for Spas

Equipotential bonding for Spas

Below is a link to a document prepared by a Florida county code official. This document clarifies the requirements for bonding of spas and pools. I believe this to be a useful document since it clearly outlines the requirements.
http://www.marioncountyfl.org/building/Forms/AlternativeMethod_EquiplBondGrid.pdf

 

[RESI]

Greg- I just installed a spa outside (VA) and had to do the following to pass inspection. This particular spa was installed on top of "Gorilla pads", basically 4 feet by 4 feet plastic pads with pavers extending out from them:

1. Install a Equipotential bonding grid extending 3 feet out from vertical walls of spa. This grid is then bonded to the ground inside the controls panel located in the spa enclosure. I purchaced the grid material from a pool supplier. It consists of either #6 or #8 bare copper wire fused together at 1 foot intervals. It comes in rolls 3 feet by 100 feet and costs about $500.00.
2. Install a GFCI disconnect greater than 5 feet from spa but no farther than 50 feet. Disconnect must be labeled " Emergency Disconnect". Disconnect must be visible from spa.
3. Install all cabling to spa in conduit and bury the conduit 18 inches.

I'll try and find the manufacturer of the EBG for you, if you like. Hope I have been of some help!


Here is the website for the EBG material. www.cmiwebsite.com