non current carrying conductors

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dwirejerker

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I have a 200 amp main panel and want to feed a 100 amp sub panel in my detached garage with a 60 amp breaker. I want to feed the sub panel with a 30 amp standby gen. I have a manual transfer switch (the kind that bolts to the inner panel cover) for the sub panel to disconnect the conductors feeding the sub panel. However I also want to feed from the sub panel back to the main panel where I would also put the same type transfer switch. There would be six conductors in the 1 1/2" conduit that is already underground. Will there 3 ccc's or 5 current carrying conductors in the 1 1/2" conduit?
 
Wecome!

While considering Larry's question, look over 310.15(B)(4)(a). We'll assume a single phase system, so your answer may be an even number.
 
dwirejerker said:
I have a 200 amp main panel and want to feed a 100 amp sub panel in my detached garage with a 60 amp breaker. I want to feed the sub panel with a 30 amp standby gen. I have a manual transfer switch (the kind that bolts to the inner panel cover) for the sub panel to disconnect the conductors feeding the sub panel. However I also want to feed from the sub panel back to the main panel where I would also put the same type transfer switch. There would be six conductors in the 1 1/2" conduit that is already underground. Will there 3 ccc's or 5 current carrying conductors in the 1 1/2" conduit?
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6..............
 
But if the neutral carries only the unbalanced current, it need not be counted 310.15(B)(4).

If it carries the complete current of leg 'A', then leg 'B' need not be counted.

Besides, there should only be One neutral in the conduit, or else 310.4 violation.

The six should be:
L1
L2
N
EGC

L1a
L1b

4 ccc's.
 
Volta said:
But if the neutral carries only the unbalanced current, it need not be counted 310.15(B)(4).

If it carries the complete current of leg 'A', then leg 'B' need not be counted.

Besides, there should only be One neutral in the conduit, or else 310.4 violation.

The six should be:
L1
L2
N
EGC

L1a
L1b

4 ccc's.
Click to expand...



I agree the neutral is a violation. We're discussing what the op already has in place. Also, can you clarify this?
 
Responding to what Larry Fine asked, there will be only 3 conductors carrying current at any one time. If the gen. is not being used then 2 hots and the unbalanced load on the neutral. If the gen. is on line the answer is the same.......I think.
 
mcclary's electrical said:
I agree the neutral is a violation. We're discussing what the op already has in place. Also, can you clarify this?
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If the netral is carrying all the current of leg A then leg B has no current flowing and you only have two CCC's going each way for a total of four.

Roger
 
roger said:
If the netral is carrying all the current of leg A then leg B has no current flowing and you only have two CCC's going each way for a total of four.

Roger
Click to expand...

So let me get this straight. You count the feeders with current flowing on them and not the neutral but, you do count the feeders with no current flowing on them.
 
One last thing on this Bob, would you point me to a code reference. The reason this came up was I was looking at a NECA article about a two speed situation with two sets of conductors and they didn't count one set. Now I can't find the article.
 
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