Sizing neutral for a hot tub

Status
Not open for further replies.
crtemp

crtemp

Senior Member
Location
Wa state
Just curious if a neutral can be smaller than the ungrounded conductors for a 60 amp hot tub circuit. I'm assuming that the neutral is only used for the lights and electronics. Would it be allowed to run two #6 thhn conductors for the hots and a #8 for the neutral? I've looked in the branch circuits and feeder calculation section of the nec but only see where it talks about derating a feeder neutral.
 
crtemp said:
Just curious if a neutral can be smaller than the ungrounded conductors for a 60 amp hot tub circuit. I'm assuming that the neutral is only used for the lights and electronics. Would it be allowed to run two #6 thhn conductors for the hots and a #8 for the neutral? I've looked in the branch circuits and feeder calculation section of the nec but only see where it talks about derating a feeder neutral.
Click to expand...


Unfortunately if you are installing the branch circuit part of the wiring then there is no allowance for a smaller neutral. I asked this very question to the cmp members at our annual meeting. Of course, I said the first part to the disconnect with overcurrent protective device could be smaller since it was a feeder so the entire rule made no sense. They argued that really the entire run was a branch circuit. I agree but that is not what the code states.
 
Dennis Alwon said:
Unfortunately if you are installing the branch circuit part of the wiring then there is no allowance for a smaller neutral. I asked this very question to the cmp members at our annual meeting. Of course, I said the first part to the disconnect with overcurrent protective device could be smaller since it was a feeder so the entire rule made no sense. They argued that really the entire run was a branch circuit. I agree but that is not what the code states.
Click to expand...

Damn. Okay, thanks for the info
 
rcarroll said:
Hopefully you have the specs for the hot tub.
The last one I hooked up required all conductors to be #6 not to exceed 80'.
Click to expand...


I have seen a few tubs that require the equipment grounding conductor to be sized the same as the current carrying conductor's. This kills the use of nm cable in the interior part of the dwelling where the code specifically allows it for the tub
 
Dennis Alwon said:
I have seen a few tubs that require the equipment grounding conductor to be sized the same as the current carrying conductor's. This kills the use of nm cable in the interior part of the dwelling where the code specifically allows it for the tub
Click to expand...

Lol
These hot tub manufactures are a pain in the ass. What would be the point of the ground being the same size as the hots?

I haven't seen the hot tub yet. Where would all of these special rules be located? On the inside of the Jbox cover? I'll doing the job tomorrow so I'll see what I can find.
 
crtemp said:
Lol
These hot tub manufactures are a pain in the ass. What would be the point of the ground being the same size as the hots?

I haven't seen the hot tub yet. Where would all of these special rules be located? On the inside of the Jbox cover? I'll doing the job tomorrow so I'll see what I can find.
Click to expand...


Check the manufacturers instructions.
 
I will add that it has been 4-5 years that I have seen a tub with those specs. I usually just use PVC in the crawl space and I am safe code wise
 
Status
Not open for further replies.
Top