#6 thhn wire

[infinity]

This was way back in I can't remember the code cycle,(probably at least twenty years ago) but if you went by Table 9, the calculations would prohibit 3 #6 and one #10, but if you went by annex C, 4 #6 were allowed.
Just ran the calcs in the 2011 edition, and it will work now as it has for a while, but......since conduit area is now listed for individul types, 4 # 6 thhn will not fit in a 3/4" schedule 80 pvc or ENT (smurf pipe) and just barely under on schedule 40 pvc. It could have been a screw up in that old edition, as there have occasionally been a few over the years.

Yes, I believe that those tables did contain some errors over the years. However, the stuff is Annex C is for informational purposes only. Saying that "you could pull 4 #6 thhn in a 3/4" conduit, but could not pull 3 #6 and a #10 in a 3/4" conduit because of a different table you had to use" was never really correct for the same conduit type even if it said so in one of the Annex C tables. You have always been required to calculate fill by doing the calculation.

 

[Hendrix]

As many as the code will allow.

OK, that may be just a little too vague.:grin:

 

[hillbilly1]

Yes, I believe that those tables did contain some errors over the years. However, the stuff is Annex C is for informational purposes only. Saying that "you could pull 4 #6 thhn in a 3/4" conduit, but could not pull 3 #6 and a #10 in a 3/4" conduit because of a different table you had to use" was never really correct for the same conduit type even if it said so in one of the Annex C tables. You have always been required to calculate fill by doing the calculation.

Why have Annex C then if it is not accurate? One would assume some sort of accuracy. But then you know what happens when you assume. :roll: I do not trust engineers anymore, because of even the simplest things they screw up now, but then again, maybe I just didn't pay close enough attention to them before!

 

[infinity]

Why have Annex C then if it is not accurate? One would assume some sort of accuracy. But then you know what happens when you assume. :roll: I do not trust engineers anymore, because of even the simplest things they screw up now, but then again, maybe I just didn't pay close enough attention to them before!

I agree, but they tell us that Annex C is there for information purposes only. Maybe it should just part of the code, but that would be too easy. :grin:

 

[K8MHZ]

Why have Annex C then if it is not accurate? One would assume some sort of accuracy. But then you know what happens when you assume. :roll: I do not trust engineers anymore, because of even the simplest things they screw up now, but then again, maybe I just didn't pay close enough attention to them before!

If there was an error, it's likely not the fault of an engineer. Most likely it was a typo made by someone with no engineering experience at all.

Annex C is there for our benefit. It lists the most common applications and does the math for us. It could be eliminated and the code would still be the same. I would much rather have a chart to glance at than have to do math figure out common everyday applications.

No annex is a part of the requirements, they are there for informational purposes only.

Now if a code book allowed 4 #6 in one area, but disallowed 3 #6 plus a #10 somewhere else, the error would not have been in Annex C. It would have been in Chapter 9, Table 5 which precedes the annexes and is part of the requirements.

 

[K8MHZ]

I agree, but they tell us that Annex C is there for information purposes only. Maybe it should just part of the code, but that would be too easy. :grin:

Anyone that has a problem with the annexes can choose to ignore them like they weren't there. There is nothing in the annexes that can't be figured out with the information given in the nine chapters preceding the annexes.