Hot tub bonding wire and ground size

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finster1

Member
Location
New Jersey
I installed a 50a gfci for a hot tub with 3 Cu #6'S two hots and neutral and 1cu #8 ground. In the interior of the building I used 3/4 emt and on the exterior I used one inch pvc with 4 #6 cu conductors from the GFCI panel I installed. The inspector tells me for a hot tub the ground wire should have been a #6 to the gfci also from the panel and that the bond wire should also be a #6 solid to the grid under the concrete of the tub. I did install a #6 to the grid but I bonded the motors with #8 solid cu wire. So we have from the main panel 3 #6thhn cu and 1 #8thhn cu to the GFCI, ALL RUN IN 3/4" EMT to the GFCI. Than to the hot tub I have 4 #6cu thhn in non metalic pvc conduit and the hot tub bond is #6 under and I used #8 to bond the motors to the metal frame of the tub...I dont see any problem at all and have installed many this way before but this inspector thinks otherwise..........What do you you guys my peers think??????????I could read the code book all day long and make all kinds of interpetations....
 

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
It isn't really in the code book, but could be in the instructions for the hot tub. Some appliances want the equipment ground to be the same size as the circuit conductors. I don't know why --are they dumb, just cutting and pasting, or is there a real technical reason for that? So check your install manual and see what it requires for an equipment ground.

I think you could even argue that you met the letter of the law if the tub needs a #6 EGC, since that is what you ran part way (from the GFCI on). What would you need to do if this tub was connected to a 100A subpanel, and that sub had a #8 copper EGC in its feeder? Would it make sense to have to run a #6 from that panel all the way to the tub when there is only a #8 upstream? Would they make you increase the EGC in that 100A feeder to a #6 (could be difficult it is a cable)?

I don't know where he's getting the #6 to the equipotential grid connection. Code is #8 for that, but again could be an instructions thing.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I have this to say

680.26 Equipotential Bonding.
(A) Performance. The equipotential bonding required by this section shall be installed to reduce voltage gradients in the pool area.

(B) Bonded Parts. The parts specified in 680.26(B)(1) through (B)(7) shall be bonded together using solid copper conductors, insulated covered, or bare, not smaller than 8 AWG or with rigid metal conduit of brass or other identified corrosion-resistant metal. Connections to bonded parts shall be made in accordance with 250.8. An 8 AWG or larger solid copper bonding conductor provided to reduce voltage gradients in the pool area shall not be required to be extended or attached to remote panelboards, service equipment, or electrodes.

Now if we are talking EGC then many manufacturers require the same size egc as the branch circuit conductors.
 
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finster1

Member
Location
New Jersey
It isn't really in the code book, but could be in the instructions for the hot tub. Some appliances want the equipment ground to be the same size as the circuit conductors. I don't know why --are they dumb, just cutting and pasting, or is there a real technical reason for that? So check your install manual and see what it requires for an equipment ground.

I think you could even argue that you met the letter of the law if the tub needs a #6 EGC, since that is what you ran part way (from the GFCI on). What would you need to do if this tub was connected to a 100A subpanel, and that sub had a #8 copper EGC in its feeder? Would it make sense to have to run a #6 from that panel all the way to the tub when there is only a #8 upstream? Would they make you increase the EGC in that 100A feeder to a #6 (could be difficult it is a cable)?

I don't know where he's getting the #6 to the equipotential grid connection. Code is #8 for that, but again could be an instructions thing.
Thanks,
My thought is being it is all run in EMT and it was done correctly that I effectively exceed the #6 he is asking about because I have a #8 + the 3/4" conduit to the main...overkill in my book but he is the ahj....I also like I said ran the 4#6's to the spa from the GFCI. Thanks again for your input.........
 

GaryFink

Member
what do you have to do to get it passed? keep the inspectors happy and provide him a copy of Soar's Book of Grounding for Christmas.
 

finster1

Member
Location
New Jersey
I would love to but the run i made would require me to pull out the # 8 and the run was through the house and in all very tight spots in a crawl space or I would just do it... But I would like to here why the 3/4" emt run + # 8thhn does not > or = to a number 6 thhn conductor. I dont think many of these inspectors realize you dont need a ground in most items in a continous run of conduit unless there is a device calling for which in this case it is...It makes me feel better that SUEMARKP agrees with me that this is a suitable ground....otherwise I am starting to lose faith that nobody will use common sense.....The code book is a minimum criteria not the bible...if you exceed the code you are still in compliance with the code....Common sense..has the world given up on this notion.....I hope not.
 
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