1 feed, 2 conduits

[david luchini]

I don't think you made the exception of using a RMC nipple in this case.
Put it this way I don't think the code intended for multiply nipples. While it may be a nipple, in thought, but it's still a raceway.

Not sure what you're trying to say. Yes, it's still a raceway, and is allowed to be filled to 60%. 3#1+1#6 THHN would have an area of 0.5193 sq. in. The 1" rigid would have an allowable fill of 0.532 sq. in. The conductors fit the fill requirements.

If they cut the conduits at floor level they would not make the exception of 250.86 Exc #2 cause they don't know how it's attached.

If they they leave some conduit can one put a hogs head on it, or a thread-less coupling, your box and a bonding bushen, and do as you imply?

I'm not suggesting he cut the conduit flush to the floor, just that he cut the length to 24". He noted a 12" attic floor depth, so he'd have 6" to work with at both ends.

 

[cadpoint]

... Not sure what you're trying to say. Yes, it's still a raceway, and is allowed to be filled to 60%. 3#1+1#6 THHN would have an area of 0.5193 sq. in. The 1" rigid would have an allowable fill of 0.532 sq. in. The conductors fit the fill requirements.
I'm not suggesting he cut the conduit flush to the floor, just that he cut the length to 24". He noted a 12" attic floor depth, so he'd have 6" to work with at both ends.

I don't have any problem with your suggestion or the math. But it really got me thinking. I drew me into chapter 9, then indexed nipple and raceways. 110.7, then I thought about that nipple - bonded or not.

They don't know the construction and a nickel to a dime that conduit is tied into rebar under the slab. Something held it in place, when the floor was poured. An Example is one piece of rebar holding them upright and would be enough to require bonding it.

They didn't make the exception of 250.86 (1)(3), till they X-ray or look at the details of the sleeves of the original construction drawing, they don't know what's there, is my point.

 

[david luchini]

I don't have any problem with your suggestion or the math. But it really got me thinking. I drew me into chapter 9, then indexed nipple and raceways. 110.7, then I thought about that nipple - bonded or not.

They don't know the construction and a nickel to a dime that conduit is tied into rebar under the slab. Something held it in place, when the floor was poured. An Example is one piece of rebar holding them upright and would be enough to require bonding it.

They didn't make the exception of 250.86 (1)(3), till they X-ray or look at the details of the sleeves of the original construction drawing, they don't know what's there, is my point.

Sure, but the exception is "not" being required to connect the EGC to the raceway. There isn't any reason for them not to connect the EGC as they 24" rigid is part of the complete circuit raceway, so they don't need to meet the exception.

And in any event, exception 1 to 250.86 is for using metal raceways for conductors ADDED to existing installations of open wire, knob and tube wire, and NM cable. This didn't sound like an addition to any of those types of wiring systems, so 250.86 Ex 1, wouldn't apply anyway.

 

[cadpoint]

Why I don't quote Code here... Thanks for reaffirming it

:grin:

250.86 exception (1)3)