conduit fill

[kwired]

How many miles would it need to be? Depends on voltage I guess



Paralleled conductors?

Well parallel conductors are technically a way to make a larger effective conductor out of two or more smaller ones, and the end result is what sort of matters the most, but I thought I had a good example of where you might find a single 3/0 per ungrounded conductor and still be required to have a 1/0 EGC run with it.

 

[480sparky]

Well parallel conductors are technically a way to make a larger effective conductor out of two or more smaller ones, and the end result is what sort of matters the most, but I thought I had a good example of where you might find a single 3/0 per ungrounded conductor and still be required to have a 1/0 EGC run with it.

When you parallel circuits, you can't down-size the ground. Each run must have a full-sized EGC. So maybe this is 4 parallel runs on an 800a breaker,

 

[kwired]

When you parallel circuits, you can't down-size the ground. Each run must have a full-sized EGC. So maybe this is 4 parallel runs on an 800a breaker,

Right, for some reason I wasn't thinking multiple raceways with only one set per raceway. (it is monday morning)

 

[infinity]

annex C is only if all the conductors are the same size

True but it still works for the OP's example. One size EMT is maximum 3-#3/0, next size EMT is maximum 5-#3/0, no calculation needed. The fact that the EGC is smaller doesn't matter.

 

[steve66]

Sure you can do that sometimes but in some cases that wont work and you aren't guaranteed the smallest conduit. Imo, it is best to calculate when there are different sizes--

that was just meant as an example. I wasn’t going to work out exactly what size breaker would require 1/0 because it doesn’t really matter.

and, yes, a tap is another good example, and one I didn’t think of.

Sure you can do that sometimes but in some cases that wont work and you aren't guaranteed the smallest conduit. Imo, it is best to calculate when there are different sizes--

but it works perfectly for this example because(4) 3/0’s and (5) 3/0’ s both require the exact same conduit size. so as long as the ground wire isn’t bigger than 3/0 it doesn’t matter. (Not that I would want to be the one to have to pull the wire in that conduit)

 

[Dennis Alwon]

Guys I know it works perfectly for this examples. My statement earlier was to say that it doesn't always work out like that. Just a precaution besides the next time the op may need to do the calc

 

[ggunn]

http://conduitfillcalculator.com/

Since you mentioned it first, I like this one: http://www.electrician2.com/rveltrain05/rf_calculator.html

Here's the one I use: http://conduitfillcalculator.com/

 

[electrofelon]

Since you mentioned it first, I like this one: http://www.electrician2.com/rveltrain05/rf_calculator.html

Here's the one I use: http://conduitfillcalculator.com/

Its kinda hard to find one that does compact conductors. The southwire calculator does compact.

 

[Dennis Alwon]

What I love about Annex C is that you can install 1967 #18 KF-2 fixture wires in 4" EMT.... I am glad to know that... LOL When I redid these tables I used all the wire types rather than just the standard ones that were in the original tables. Never thought about how ridiculous some of these results would come out to be.