Feeder lines

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can you have a 3 inch sleeve going through concrete and install (2) 100 amp feeder lines in 1 1/2 conduit through the 3 inch sleeve going into the crawl? Or are you just allowed to have one feeder line per sleeve. This is for a project in Seattle.
 

infinity

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The NEC is silent on what can go in the sleeve. We often run multiple conduits through a large sleeve.
 

GoldDigger

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The NEC is silent on what can go in the sleeve. We often run multiple conduits through a large sleeve.
Which leaves the open question of whether ampacity adjustment calculations apply individually to each raceway or to the whole thing as a single duct duct bank.

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jumper

Senior Member
Which leaves the open question of whether ampacity adjustment calculations apply individually to each raceway or to the whole thing as a single duct duct bank.

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Ah gee whiz, ya had to bring that up.:D

Since it is not to my advantage, I like to ignore the single duct idea. My rational is that since it is a sleeve and not continuous I do not have to apply any extra derating by totaling conduits.

Anybody buying this?
 

Ponchik

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Ah gee whiz, ya had to bring that up.:D

Since it is not to my advantage, I like to ignore the single duct idea. My rational is that since it is a sleeve and not continuous I do not have to apply any extra derating by totaling conduits.

Anybody buying this?

I will buy it. IMO sleeves are not considered a conduit or a cable. (edited)
 

Ponchik

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Cool. I will PM you my pay pal account #.:)

Actually I am in SF visiting so I can swing by and pick up a check if that is that more convenient.

Cool beans!! enjoy the visit. :thumbsup::thumbsup:
 

GoldDigger

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In terms of the actual heat equation calculation (Neher/McGrath), the heating effect of multiple individual wires inside a raceway, duct, or sheath underground will be the same regardless of whether or not some of the wires happen to be inside a cable sheath as well. But the applicable code language seems to treat them differently.

It is not clear to me from the OP's post whether this is a sheath for any substantial distance embedded in concrete or just a sleeve for a wall penetration, which would be short enough that the code does not care about it.
 

kwired

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NE Nebraska
If this sleeve is just through a wall I don't think any adjustments are necessary, until the sleeve becomes more then 2 feet long anyway
 

Ponchik

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CA
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If this sleeve is just through a wall I don't think any adjustments are necessary, until the sleeve becomes more then 2 feet long anyway

So you are saying if I install conduits through a 36" sleeve I need to derate? or debatable to derate or not?
 

infinity

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If this sleeve is just through a wall I don't think any adjustments are necessary, until the sleeve becomes more then 2 feet long anyway

Where in the NEC does it say anything about derating for conduits next to each other in a sleeve of any length?
 

Ponchik

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CA
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All I am saying is you don't need to even think about applying adjustments unless this condition is longer then 24 inches.
IMO, even if the sleeve is longer than 24" adjustment factor does not apply.
 

infinity

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IMO, even if the sleeve is longer than 24" adjustment factor does not apply.

I agree and I can see how Kwired is thinking with the more than 24" but as you've stated there is nothing in the NEC that would direct you to consider the multiple EMT's through a sleeve for derating.
 
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