Manufactired Spa Bonding

[FionaZuppa]

so, just wondering what others have been told or have experienced. i have a UL listed manufactured "above-ground" spa. this spa sits within a "vault" in the ground, 18" below grade and 18" above grade. my town folks tell me equi-bonding is not needed (using nec 2011 book). i myself still like safety so i did added a copper coil (12" spacing) under the concrete pad and will be tied to several ground spikes (including spa chassis and service gnd) and i'll add some wire under the areas where people will walk outside the spa, but still wondering if equi-bonding is a requirement. my town folks say that even though its half in/out the spa itself is considered an "above ground" item and that since it is UL listed there is no need for equi-bonding.

is there any firm definitions of what "in-ground", "above-ground", and "on-ground" means as i have seen these terms used all over the place. i myself would classify any item that has any portion of the installation below grade as an "in-ground" item, "on-ground" being at grade and above, and "above-ground" as being the full unit sits above grade.

given i dont fully trust my town folks (they seem to err on the lighter side of requirements) i am looking for some feedback.

 

[Dennis Alwon]

IMO equipotential bonding is needed. Even with the Tia you would be required to have this bonding

 

[Dennis Alwon]

The equipotential bonding does not go under the tub but rather 18-24 from the inside wall of the tub and 4-6 inches deep. This run of copper shall encompass the perimeter of the tub

 

[Dennis Alwon]

Outdoor tubs must follow the same rules as a pool, therefore the equipotential bonding is necessary. The wiring inside a dwelling can be of Chapter 3 wiring methods but once outside it must follow the pool rules.

 

[FionaZuppa]

The equipotential bonding does not go under the tub but rather 18-24 from the inside wall of the tub and 4-6 inches deep. This run of copper shall encompass the perimeter of the tub

yes, i know, i added extra safety.

so, looks like certain scenarios exempt self-contained spas from equi-bonding, i fail Exception #2(2), and i dont know what they mean by "on or above grade" in 2(1), but since i have my item 50/50 in/out of the ground it looks like i need the bonding on perimeter. see attached pic for top view and elevation.

i guess next Q is, for a UL listed spa that is 50/50 in/out of ground (sitting in a concrete vault) where the vault is bigger than the spa, as example, my spa is 83x83" but the vault is 85x108", where the extra space is an access area for spa maintenance & sump pump, and such area is closed by an wood access floor-panel at grade level, does the perimeter bonding need to bond the floor in this access area (which is 18" below grade), and the wooden floor-panel? i thought i also read elsewhere that the perimeter bonding is only needed where people can walk next to item. if 50% of the perimeter is protected from foot traffic by a gate or wall, does that area need perimeter bonding?

680.42(B) Bonding.
Bonding by metal-to-metal mounting on a common frame or base shall be permitted.
Exception No. 1: The metal bands or hoops used to secure wooden staves
shall not be required to be bonded as required in 680.26.
Exception No. 2: A listed self-contained spa or hot tub that meets all of the following conditions shall not 
be required to have equipotential bonding of perimeter surfaces installed as required in 680.26(B)(2):
(1) Is installed in accordance with manufacturer?s instructions on or above grade.
(2) The vertical measurement from all permanent perimeter surfaces
within 30 horizontal inches (76 cm) of the spa to the top
rim of the spa is greater than 28 inches (71 cm).

 

[FionaZuppa]

i tried to attach, but that 15min window ran out. can i bond just the purple area?

 

[FionaZuppa]

hah, i spoke to the pool co who i bought spa from, i asked if they have done these spas 50/50 in/out ground before (vaulted). he said they have done like 500 of them over the years. then i asked if they do equi-bonding, the sales guy didnt know, but he said he didnt think so, but he had his sub electric guy talk to me, and nope, they dont do it. in the past the "portable" verbiage for UL listed spas allowed them to get away w/o bonding of any sort, but our discussion did spark some interest on his side. and as i suspected, my town folks are not up-to-speed with various codes.

i still have some open Q's around the perimeter bonding, but i will need to add some.

and another Q, did the bonding requirement change from 6awg to 8awg?