Question on upsizing conductors

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Mustwin351

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The situation without a long backstory:

One raceway with 10 current carrying conductors. Taking into account derating the conductors at 50% ampacity they will have to be upsized. Problem is then my conductors are one size too large for their circuit breakers.

I'm pretty sure it is not possible to use the smaller size conductor from the breakers to enter a box, gutter, or wire way, and then at that point go to the correct size conductors so that they then can all run in the same conduit. This would be a violation correct?
 
richie921 said:
What do u mean too large for the breaker? The conductors will not physically fit??

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Correct. Breaker only will accept up to #8 and with derating I would be at #6

(ideal situation would be to run a feeder to a sub panel and avoid this)
 
What brand is breaker? Ive never seen a 40 or 50 amp breaker not be able to fit a #6. How about putting a disco next to the panel fed with #8 and then run #6 out the load side. Disco would be under 10 bucks and if theres room around panel u could prob put it in in under 20 min.

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Mustwin351 said:
I'm pretty sure it is not possible to use the smaller size conductor from the breakers to enter a box, gutter, or wire way, and then at that point go to the correct size conductors so that they then can all run in the same conduit. This would be a violation correct?
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Can you make this apply?

310.15(A)(2)Exception

(2) Selection of Ampacity. Where more than one ampacity
applies for a given circuit length, the lowest value shall be used.
Exception: Where two different ampacities apply to adjacent
portions of a circuit, the higher ampacity shall be permitted
to be used beyond the point of transition, a distance equal to
3.0 m (10 ft) or 10 percent of the circuit length figured at the
higher ampacity, whichever is less.
 
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Sorry I read it quickly and saw the number 8 and number 6 and just assumed that was the upsizing. Now I see you're at a 50% derating exactly what amperage would the circuit be without any derating, 30?

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richie921 said:
Sorry I read it quickly and saw the number 8 and number 6 and just assumed that was the upsizing. Now I see you're at a 50% derating exactly what amperage would the circuit be without any derating, 30?

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yes 30 amp square d breaker.

I have two 30 amp circuits, and four 20 amp circuits. So technically 14 current carrying current conductors.
 
Mustwin351 said:
...I'm pretty sure it is not possible to use the smaller size conductor from the breakers to enter a box, gutter, or wire way, and then at that point go to the correct size conductors so that they then can all run in the same conduit. This would be a violation correct?
Click to expand...

No violation. No problem. No reason not to do it.
 
You can splice on a short length of #10 to the #6 ungrounded conductors in the panel.
 
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The voltage drop will be insignificant if you just splice a short piece of a smaller conductor as long as that piece is rated for the breaker.
 
Dennis Alwon said:
The voltage drop will be insignificant if you just splice a short piece of a smaller conductor as long as that piece is rated for the breaker.
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What if my short piece has to extend from the panel more than 24" in a raceway before I can make the splice?

Voltage drop is not a concern in this case as I'm only increasing the conductors in size because there are more than 3 ccc in the raceway.
 
Mustwin351 said:
What if my short piece has to extend from the panel more than 24" in a raceway before I can make the splice?

Voltage drop is not a concern in this case as I'm only increasing the conductors in size because there are more than 3 ccc in the raceway.
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Then you have a derating problem unless 310.15(A)(2) applies.

I would make the splice in the panel.
 
Theres no prob or violation splicing in panel. Though technically allowed Im not a fan of splicing 2 conductors so different in gauge. 12 to 14 fine 12 to 10 ok but 10 to 6, eh. Just not a fan. Unless they were joined in a polaris tap, thatd be fine. Love the Burndy idea.

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Im missing something in the count. 2-30 amp and 4 20 amp circuits if all single pole would be 12 ccc not 14 right. If the system is single phase, run them as multiwire branch circuits on a 2 pole 30 and 2-2 pole 20s. Now youd be at 6 ccc (neutrals carrying unbalanced load dont count) and only have to derate to 80 percent.

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Mustwin351 said:
I'm pretty sure it is not possible to use the smaller size conductor from the breakers to enter a box, gutter, or wire way, and then at that point go to the correct size conductors so that they then can all run in the same conduit. This would be a violation correct?
Click to expand...
Perfectly fine to do or as already stated, just splice to smaller conductors in the panel.

Roger
 
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