per cent fill on conduit

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srmoran

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I have 3-1000kcmil, 25 kv and 1-1000kcmil, 600v cable in 155mm conduit. My per cent fill is 43% which is above the 40 % limit. Is there any exception to this?
 
Re: per cent fill on conduit

I cannot think of an exception unless the conduit is a nipple not exceeding 24" length.

What is the function of the 1000KCMIL 600V. insulated conductor?
Does it really need to be that large?
 
Re: per cent fill on conduit

Originally posted by srmoran:My per cent fill is 43% . . . .
Click to expand...
How did you arrive at that value? If you found it by dividing the actual area of each conductor by the area inside the conduit, then you are stuck with a problem: find smaller conductors or a larger conduit. But I am guessing that neither option is available to you, or at least neither is attractive.

[ December 12, 2005, 11:22 AM: Message edited by: charlie b ]
 
Re: per cent fill on conduit

What about looking into compact conductors. I've been told that they now come in copper as well as aluminum. You might just get under the 40% you're looking for.
 
Re: per cent fill on conduit

Is 600 v cable allowed in a conduit with 25KV??? I thought everything had to be rated for the highest voltage present??

Steve
 
Re: per cent fill on conduit

Good catch, Steve. This would be a violation of 300.3(C)(2).

That's one ATTABOY :) for Steve and one OOPS :( for me.
 
Re: per cent fill on conduit

Good catch, Steve. This would be a violation of 300.3(C)(2).
Click to expand...
300.3(C) deals with Conductors of different systems.
I do not think the 1000 kcm is part of a different system. Its the neutral or grounded conductor of the 25 kv system. I believe it can be bare.
 
Re: per cent fill on conduit

If it's a ground, and can be bare, that decreases the overall diameter...maybe enough to meet the 40% rule.

john
 
Re: per cent fill on conduit

250.184(A)(1) requires the neutral (grounded) conductor of this system to have insulation rated at 600 volts.
Don
 
Re: per cent fill on conduit

I get it now. I didn't know the neutral was allowed to have a lower voltage rated insulation.

I was kind of puzzled why a 600V conductor was in a conduit with high voltage!
 
Re: per cent fill on conduit

srmoran: Can you tell us what the 1000 MCM 600V conductor is? Also, can you answer my previous question?
 
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