Conduit Fill

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enosez

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I will start by saying that I am scheduled to attend NEC training In the Spring of 2008. That being said I am trying to referance the 1993 NEC. So please be patient with me.

My question is we have to run five 2/0 conductor and five #2 conductor to a j-box in the ceiling. I am using the conduit fill table (from 93) which states I can fit eight 2/0 OR sixteen #2. Can i fit five 2/0 and five #2 in a 2 1/2" emt which will have 1 LB and 1 90 and 2 45's?

Thanks for your help!!!!
 
You are going to have to determine the total area of all the conductors installed in the conduit according to Table 8 and then make sure that the total are of the conductors doesn't exceed 40% of the cross sectional area of the conduit specified in Table 4.

If you have different size conductors you can't use values given in Table 3.

Chris
 
enosez said:
I will start by saying that I am scheduled to attend NEC training In the Spring of 2008. That being said I am trying to referance the 1993 NEC. So please be patient with me.

My question is we have to run five 2/0 conductor and five #2 conductor to a j-box in the ceiling. I am using the conduit fill table (from 93) which states I can fit eight 2/0 OR sixteen #2. Can i fit five 2/0 and five #2 in a 2 1/2" emt which will have 1 LB and 1 90 and 2 45's?

Thanks for your help!!!!
Click to expand...

From a quick glance at the tables in 05 NEC I would say your numbers are right if you're running THHN.
 
OK So I think I've got it.
According to the 93 NEC I have table: (THHN)
5 2/0 @ .2265 comes to 1.1325 and 5 #2 @ .1182 comes to .591
Together I get 1.7235 which is below the 1.92 allowed in Table 4.

I sure hope that LB cooperates.

Thanks for your help guys.
 
A quick hit.............

Conduit fill and LB's are a bit diff.

Many makers of LB's have the max size wire stamped inside the fitting.
 
enosez said:
I will start by saying that I am scheduled to attend NEC training In the Spring of 2008. That being said I am trying to referance the 1993 NEC. So please be patient with me.

My question is we have to run five 2/0 conductor and five #2 conductor to a j-box in the ceiling. I am using the conduit fill table (from 93) which states I can fit eight 2/0 OR sixteen #2. Can i fit five 2/0 and five #2 in a 2 1/2" emt which will have 1 LB and 1 90 and 2 45's?

Thanks for your help!!!!
Click to expand...
Yes if we can assume thhn.You might want to think of how long and how many 90's.Legal and doing are not the same
 
enosez said:
I sure hope that LB cooperates.
Click to expand...
Well if your not happy with it:

2 1/2" emt connector to 2 1/2" to 3" reducing bushing to 3" LB then back.

And you have me wondering what is the application?
 
Its a feed to a processing machine.
It is currently run with 5 #2 wire. We are in the process of moving this machine and replaceing it with a newer version.

This time a site survey was supplied and it specifies 2/0 wire. Only problem is that we still have to supply the other 5 #2 wires for another machine in the same conduit.

On the LB, I'm trying to use a 90 in place of it. It may work if we can move some attachements on the pole.
 
enosez said:
This time a site survey was supplied and it specifies 2/0 wire. Only problem is that we still have to supply the other 5 #2 wires for another machine in the same conduit.
Click to expand...
Is it possible to use this conduit for feeders to a sub-panel, and branch out to the separate machines from there? That would eliminate derating issues.
 
I dont think so because:

According to the machines requirements we are supposed to put three machines on a 150 kva transformer. All are supposed to be run with a minimum 2/0 copper wire.

What we have is four machines on a 150 kva transformer. All are run with #2. Since its been working since installation, (some 15 years ago), the Manager doesnt want to touch what he sees as a problem that doesnt exist.

However, since one of those machines is being placed in another part of the building, we have a chance to correct at least the machine going in its place.

The power panel is already at max and because of its placement on the pole with thransformer on one side of the pole and a stand pipe on the other, I have no room to really run another conduit. Thats why we are going to pull out the 1 1/2 and replace it with 2 1/2 and run both those feeds through it.

Its a start!!
 
chris kennedy said:
Well if your not happy with it:

2 1/2" emt connector to 2 1/2" to 3" reducing bushing to 3" LB then back.

And you have me wondering what is the application?
Click to expand...

:rolleyes: Wouldn't a 2 1/2" to 3" bushing be an expansion bushing as opposed to a reducing bushing?:rolleyes: :)
 
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