680.26 and indoor hot tubs

[augie47]

We just had a similar discussion on hot tubs installed outdoors. One supervisor did not feel a equipotential grid was required period based on his reading of 680.43(B). It was, however, generally accepted that a grid was required.
There were two unanswered questions during the meeting however. In 680.42(B) what does" Bonding by metal-to-metal mounting on a common frame or base shall be permitted. " mean ? We could not picture this.

Secondly: How do you guys approach a situation when a newly purchased hot tub is set outdoors on an existing concrete slab ?

 

[highvolts582]

Ive done this install and passed

Ive done this install and passed

I wired an outdoor tub in a basement in an excercise room I just made sure receptacles in the room were GFI protected. and the disconnect was more than 5 feet away. it was on a carpet though. and no metal ducts which i think if it did some bonding better be done! What if this was a big bathtub in basement? what would be the difference. I thought stray voltage from the underground power company was the reason we use equipotential bonding. also the gfi may trip better.

I did not fail lucky me.

 

[elohr46]

George, I am sorry if I am creating a problem.
I respect everyone here and appreciate everyones help.

IMO a hot tub mounted on concrete in contact with earth on the floor of a basement poses the possibility of voltage gradients as one on a concrete slab outdoors that would require perimeter bonding. I asked for opinions but have had no responses.

I am trying to be responsible to the electrician and also the resident.

I agree with you 100% that an indoor concrete slab and an outdoor concrete slab can have the same possible voltage gradient problems. Article 680 needs further refinement to say the least. I'm still trying to figure out why storable pools with 42" or less of water are to be looked at differently from those that have 43" or more of water. Can someone explain that logic?

 

[romeo]

680.26 and indoor hot tubs

I agree with you 100% that an indoor concrete slab and an outdoor concrete slab can have the same possible voltage gradient problems. Article 680 needs further refinement to say the least. I'm still trying to figure out why storable pools with 42" or less of water are to be looked at differently from those that have 43" or more of water. Can someone explain that logic?

I can't explain, because there is no logic. Wouldn't the term storable pool indicate that the intent is to store it at the end of each season, has anyone ever seen that happen?

 

[M. D.]

I contacted the executive Director of the Ma. State Board of examiners. His opinion is the way it is written 680.43 trumps 680.26(B)(2)

He does agree with my thought, that unless there is a vapor barrier,a concrete floor in a basement presents the same possibility as a slab outdoors.

End of story

Not quite ,...what did you do in regard to the original post and the failed inspection??

.....I failed the installation based on 680.43 requiring that indoor installations comply with part II of articale 680. Some seem to think that 680.26 does not apply to indoor installations. I disagree.

Please help.

 

[romeo]

680.26 and indoor hot tubs

Not quite ,...what did you do in regard to the original post and the failed inspection??

I called the electrician, told him 680.26(B)(2) did not apply and apologized for the inconvenience.

Is that what I should have done?

 

[M. D.]

I called the electrician, told him 680.26(B)(2) did not apply and apologized for the inconvenience.

Is that what I should have done?

sounds good to me,.. i was just curious is all..