why did these conductors fail inspection

[mjgilmore54]

Installing a 6 space 3R sub panel for pool equipment.Feeding sub panel from Main breaker panel useing a 70 amp 2 pole breaker. Installed 1 1/4 PVC conduit ,then ran dual rated thhn/thwwn conductors as follows: 2- # 4 for hot legs, 1- #6 for (neutral) grounded conductor and 1- #8 for equipment grounding conductor. Inspector left fail sticker that said " conductor size". Seems right to me .Any ideas?

 

[Steviechia2]

Numbers look good. I doubt your load is more than 70 amps for a pool if that is where he is going?

 

[Dennis Alwon]

Did you run a #6 white for the grounded conductor or did you tape a black wire white? Was the #8 taped green or green?

The other possibility is the inspector believes the grounded conductor must be as large as the hot conductors.

 

[infinity]

Sounds good to me.

 

[Sierrasparky]

maybe the inspector does not like a reduced nuetral conductor.
When I worked in So Cal 20 years ago it was not usually accepted. However in the North west many do it as the norm. At least show the load calcs on the nuetral.

 

[Little Bill]

Sounds good to me too.

I just did a pool a couple of weeks ago. I don't know what equipment you have, but only the lighting equipment used a neutral on what I installed. I doubt even if there was one or two other things that required a neutral that the load on the neutral would even be 10A, probably not even close to 10.
I believe I would be in touch with that inspector soon and see what he's thinking on this.

 

[mike1061]

This is something I never understood. When I was studding for my license test, I found two locations where the code said you could reduce the neutral size and two where it said you could if over 400 amps. The instructor never got back to me and I finished the class without getting the answer.
Thanks
Mike

 

[charlie b]

This is my guess:

At least show the load calcs on the nuetral.

If the inspector has no way to verify that the neutral current has been calculated to be no higher than 65 amps, then he (or she) has no basis to accept the use of a #6 THHN neutral wire.

 

[charlie b]

. . . I found two locations where the code said you could reduce the neutral size and two where it said you could if over 400 amps. The instructor never got back to me and I finished the class without getting the answer.

What's the question? I see that 220.61(B)(1) and 220.61(B)(2) give us two opportunities to reduce the neutral. Where did you see the two 400 amp versions?

 

[cowboyjwc]

This is my guess: If the inspector has no way to verify that the neutral current has been calculated to be no higher than 65 amps, then he (or she) has no basis to accept the use of a #6 THHN neutral wire.

I would guess that this is the most correct response.

Had a guy the other day that wanted me to just sign off the electrical to some equipment (equipment not installed) long story about how he got a permit, but I told him that I couldn't sign it off since I had no idea if the wire, or the fuses or anything were the correct size.

If you want to do something out of the norm, then it's you job to justify it, not my job to verify it.

 

[kwired]

Installing a 6 space 3R sub panel for pool equipment.Feeding sub panel from Main breaker panel useing a 70 amp 2 pole breaker. Installed 1 1/4 PVC conduit ,then ran dual rated thhn/thwwn conductors as follows: 2- # 4 for hot legs, 1- #6 for (neutral) grounded conductor and 1- #8 for equipment grounding conductor. Inspector left fail sticker that said " conductor size". Seems right to me .Any ideas?

I would be asking them for a better explanation than just "conductor size".

Can't speak for your AHJ, but many (probably most) if following their own rules, need to provide you with code references and descriptions of why you are in violation of the quoted references if they are going to fail an installation.

If they can't give you anything better than that - go to their supervisor. If you are in one of those places where there is no real supervisor - good luck, it is you against the inspector, and the inspector is used to getting their own way whether they are right or not.

 

[A/A Fuel GTX]

This is my guess: If the inspector has no way to verify that the neutral current has been calculated to be no higher than 65 amps, then he (or she) has no basis to accept the use of a #6 THHN neutral wire.

How about common sense and seeing what the possible neutral current will be based on the installation? We run 4/0 4/0 2/0 AL service entrance conductors all the time for 200A services and there are never any questions from the AHJ.

 

[cowboyjwc]

How about common sense and seeing what the possible neutral current will be based on the installation? We run 4/0 4/0 2/0 AL service entrance conductors all the time for 200A services and there are never any questions from the AHJ.

Not getting questioned by the AHJ doesn't always mean you're right.:happyno:

I'm not saying you're not, but the way inspectors get beat up around here could just be because he doesn't know if it's right or wrong either.:lol:

 

[infinity]

Even if it mattered #6 THWN is a 65 amp conductor next size up 70 amps.

 

[mike1061]

What's the question? I see that 220.61(B)(1) and 220.61(B)(2) give us two opportunities to reduce the neutral. Where did you see the two 400 amp versions?

This was more than 10 years ago. I'll see if I can find it, if I have time.
Thanks
Mike

 

[Sierrasparky]

well I hope the OP returns and gives an update.

 

[Dennis Alwon]

well I hope the OP returns and gives an update.

I hate when that happens. Ask a question and leave. Sometimes members get busy and don't have a chance to get back right away. I hope we get answers.

 

[Sierrasparky]

I hate when that happens. Ask a question and leave. Sometimes members get busy and don't have a chance to get back right away. I hope we get answers.

Maybe he is embarrased that he made a mistake, we all do that some time.

I had a supplier that would not stock Green or white #8 or #6. just black..Just color tape
I had to go somewhere else then he would get pissed.

 

[Glennsparky]

I did a pool with three pumps and calculated off the nameplate amps. The amps in table 430.248 were much higher. That flunked my conductors.

 

[Sierrasparky]

I did a pool with three pumps and calculated off the nameplate amps. The amps in table 430.248 were much higher. That flunked my conductors.

Where is it written that Nameplates will not be used. Have you ever seen a SPL rated motor on a compressor? Those are usually 5 HP and rated to be on a 20 amp circuit. If you look at the same table the load is over 20 amps. I have seen even a 6hp version. These SPL motors are used on compressors and only operate at peak for a short time. I bet your inspector will fail that one also.