When does a neutral count as a CCC?

[qcroanoke]

Our company is in the transportable equipment shelter industry and we always are careful not to pull more than 9 current carrying conductors
in any raceway because of the de-rate factor.
We also always pull private neutrals for all
circuits.And we count them as CCC's.
If a neutral IS NOT counted what type of load is it?
If a neutral IS counted what type of load is it?
We will continue to pull private neutrals for all of our circuits but if we don't need to count them all it will help us on our conduit installation time.
Any insight given will be appreciated!

 

[infinity]

Re: When does a neutral count as a CCC?

A shared neutral of a 3 phase system would not need to be counted if the major portion of the loads were linear. Or in other words if the majority of the loads did not contain harmonics than the neutral would not count as a CCC.

 

[don_resqcapt19]

Re: When does a neutral count as a CCC?

A grounded (neutral) conductor that only serves a single ungrounded conductor is always counted as a current carrying conductor.
Don

 

[pierre]

Re: When does a neutral count as a CCC?

Take a look at 310.15(B)(4)(b) for the details.

 

[petersonra]

Re: When does a neutral count as a CCC?

i think the answer is that it counts as a current carrying conductor if it carrys current.

if you run a seperate neutral for each circuit that neutral carrys the same amount of current as the hot lead does.

 

[don_resqcapt19]

Re: When does a neutral count as a CCC?

Bob,

i think the answer is that it counts as a current carrying conductor if it carrys current.

The neutral of a multiwire branch circuit carries current, but is not required to be counted as a current carrying conductor. The is no requirement that the loads on a multiwire branch circuit be balanced. If there is only current on one ungrounded conductor, then there will be the same amount of current on the neutral conductor. In a 3 wire multiwire circuit the most heat is produced under the following two conditions...1) one ungrounded conductor is loaded to its ampacity, or 2) both ungrounded conductors are loaded to their ampacity. Any other combination results in less total heat. The purpose of the derating rules is to protect the conductors from excessive heat. This is accomplished in a multiwire circuit without counting the neutral conductor as a current carrying conductor.
Don

 

[petersonra]

Re: When does a neutral count as a CCC?

the OP did not indicate he had multiwire circuits though. I would agree that neutrals on multiwire circuits should not be counted as current carrying.