TIA for Bonding Requirements at Spas

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bphgravity

Senior Member
Location
Florida
Following is a link to the NFPA for a TIA that is being proposed to remove the requirement for perimeter surface bonding (680.26(B)(2)) at listed, self-contained, outdoor spas and hot tubs as currently required in 680.42 of the NEC.

The premise of the proposal is that self-contained spas and hot tubs should be exempt for the perimeter bonding requirements much like storable pools and indoor spas as permitted in 680.30 and 680.43 - Exception 2, respectfully, of the 2011 NEC.

This has certainly been a hotly debated issue since the inception of the permiter surface bonding concept back in the 2005 NEC. While many code professionals and users have come to grips with all the requirements of 680.26, it has always been a gray area as to how the perimeter surface bonding is to be accomplished for a self-contained spa installed on an existing slab.

While the acceptance of this TIA would only change the 2011 NEC, it may be used as substaniation to not require the bonding of the perimeter surfacesfor permitted installations under the 2008 NEC.


http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70
 
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shortcircuit2

Senior Member
Location
South of Bawstin
With regard to the step potential...

I can't recall ever seeing a self contained Hot Tub installed below grade. The ones I have seen set-up so you can step in at grade level have a non-conductive wooden deck built around them with the tub resting on grade below usually accessible from an existing deck already raised 3-4 feet above grade. It is foolish to install a perimeter bond underneath a wooden deck.

I'm not convinced about the comments in the TIA that the person would jump back away from the tub if they were getting a jolt from putting their hand in the water with their feet on the ground and this is not a hazard.

Okay...what if this person were an adult with a newborn in one arm and places her hand in the water with the other and receives a jolt? Will she jump back and drop the infant...probably...and most likely drop the child causing serious injury or even death.

It is my opinion that the code is correct in requiring a perimeter bond, although it needs some fine tuning.

Hopefully common sense will prevail and not the almighty dollar and they will trash this ridiculous TIA.

shortcircuit2
 
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petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
maybe the answer would be to just require a metal mesh be installed under the tub as it is set in place that can be bonded to.

I don't get a lot of these kind of requirements in the first place. is there any actual evidence that the requirements actually resolve a problem that has been shown to actually be a hazard? Not just supposition and random speculation. real actual evidence.

Or maybe the answer is to be found in changing the way the tubs are made. I know that is not part of the NFPA's mission, but it seems like a self contained unit is self contained and ought to not require a lot of other work to be usable.
 
joe tedesco

joe tedesco

Senior Member
Location
Boston, Massachusetts
TIA 680.42 released

TIA 680.42 released

Tentative Interim Amendment
NFPA 70?
National Electrical Code?
2011 Edition
Reference: 680.42(B)
TIA 11-1
(SC 11-3-10/TIA Log #1005)
Pursuant to Section 5 of the NFPA Regulations Governing Committee Projects, the National Fire Protection Association has issued
the following Tentative Interim Amendment to NFPA 70?, National Electrical Code?, 2011 edition. The TIA was processed by Panel
17 and the National Electrical Code Technical Correlating Committee, and was issued by the Standards Council on March 1, 2011,
with an effective date of March 21, 2011.
A Tentative Interim Amendment is tentative because it has not been processed through the entire standards-making procedures. It is
interim because it is effective only between editions of the standard. A TIA automatically becomes a proposal of the proponent for the
next edition of the standard; as such, it then is subject to all of the procedures of the standards-making process.
1. Revise 680.42(B) to read as follows:
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).
Informational Note: For further information regarding the grounding and bonding requirements for self-contained spas and hot
tubs, see ANSI/UL 1563 ? 2009, Standard for Electric Spas, Equipment Assemblies, and Associated Equipment.
Issue Date: March 1, 2011
Effective Date: March 21, 2011
 
W

wawireguy

Senior Member
I think the code as it stands is absurd. I've never gotten in a hot tub that had a bonding grid. They are GFCI protected. What more could you need?
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
wawireguy said:
I think the code as it stands is absurd. I've never gotten in a hot tub that had a bonding grid. They are GFCI protected. What more could you need?
Click to expand...
A GFCI will not solve the problem that the perimiter bonding is intended to solve. The perimeter surface bonding is intended to rasie the voltage of that surface to match that of the water and bonded metal parts of the hot tub.
 
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