Wire Way, Conductor Ampacity, over 30 conductors

[dossrc1]

Good day everyone,
Question, i'm workin on V6000 raceway, fill is not an issue.../ Ampacity of conductors is my issue (Over 40 Cond, 30A, 3w & 5w Recps, Continuous Load...)
376.22 B states that over 30 Current carrying conductors, you must start derating per T310.15.B3a. if i don't have to de-rate under 30 conductors, once i hit 31 conductors, do i have to de-rate the conductors by 60%, then over 40 conductors by 65%. i'm dealing with #10, THHN, amps to derate from 40a in 90c coulum. so (40 x .35 = 14amps) so for 30a ckts, i would be looking at #4 THHN (95 x .35= 33.25 Amps) am I reading this correct....

 

[Dennis Alwon]

That is correct however isn't there a divider you can but for the wireway and wouldn't that allow another 30 wires??? I am not certain but that was my understanding-- I cannot find evidence of it in the NEC. Perhaps someone else can shed some light.

 

[kwired]

Good day everyone,
Question, i'm workin on V6000 raceway, fill is not an issue.../ Ampacity of conductors is my issue (Over 40 Cond, 30A, 3w & 5w Recps, Continuous Load...)
376.22 B states that over 30 Current carrying conductors, you must start derating per T310.15.B3a. if i don't have to de-rate under 30 conductors, once i hit 31 conductors, do i have to de-rate the conductors by 60%, then over 40 conductors by 65%. i'm dealing with #10, THHN, amps to derate from 40a in 90c coulum. so (40 x .35 = 14amps) so for 30a ckts, i would be looking at #4 THHN (95 x .35= 33.25 Amps) am I reading this correct....

Looks like you are on the right track to me. I would think running a second wireway likely would cost less then running over thirty 4 AWG conducotrs in place of 10 AWG in most instances.

 

[Smart $]

That is correct however isn't there a divider you can but for the wireway and wouldn't that allow another 30 wires??? I am not certain but that was my understanding-- I cannot find evidence of it in the NEC. Perhaps someone else can shed some light.

Derating requirement is for the wireway. Doesn't matter whether you use a divider, as it is still one wireway.

 

[Smart $]

... I would think running a second wireway likely would cost less then running over thirty 4 AWG conducotrs in place of 10 AWG in most instances.

+1

 

[Dennis Alwon]

Derating requirement is for the wireway. Doesn't matter whether you use a divider, as it is still one wireway.

Wouldn't a divider make it like 2 wireways? I have never used them but I am thinking that are totally separate. You are limiting the number of conductors on top of each other

 

[John120/240]

Along Dennis's line of thinking using this product in sufficiently large sizes say 4" would fill limitations apply to the whole conduit or to the individual raceways ? IDK are these products acceptable for NEC applications ?

 

[qcroanoke]

Wouldn't a divider make it like 2 wireways? I have never used them but I am thinking that are totally separate. You are limiting the number of conductors on top of each other

That's what we use it for. So we can increase our conductor count.
If that is wrong please show me where that is. I need to know.

 

[qcroanoke]

Try this link. Divider part number is G6000DA

http://assets.twacomm.com/assets/pdf/39749.pdf

 

[Smart $]

Wouldn't a divider make it like 2 wireways? I have never used them but I am thinking that are totally separate. You are limiting the number of conductors on top of each other

No. Still one wireway, but with multiple compartments.

Web page supports this interpretation...

Dividable raceway base. Snap-in divider creates two-compartment raceway. For bringing large amounts of power and data/communications cable to one location.

...as does 386.70 (but quite vaguely).

 

[kwired]

No. Still one wireway, but with multiple compartments.

Web page supports this interpretation...

...as does 386.70 (but quite vaguely).

I did not check out 386.70, but seems to me the topic there is about separation of power and communications more so then creating two wireways for the purpose of relieving deration requirements.

What if I had two separate wire ways, but installed them so they are butted against each other along the linear dimension? Is not the same thing as installing a divider but is almost the same thing. Would we be able to install 30 current carrying conductors in each before the need to adjust conductor ampacites? If one had less then 30 and the other more then 30 is each one still determined separately?

 

[don_resqcapt19]

What is the length of the wire in the wireway as compared to the total length of the wire from end to end?

 

[Smart $]

I did not check out 386.70, but seems to me the topic there is about separation of power and communications more so then creating two wireways for the purpose of relieving deration requirements.

Separation yes, but uses the term separate compartments.

What if I had two separate wire ways, but installed them so they are butted against each other along the linear dimension? Is not the same thing as installing a divider but is almost the same thing. Would we be able to install 30 current carrying conductors in each before the need to adjust conductor ampacites? If one had less then 30 and the other more then 30 is each one still determined separately?

The short of it is, 386.6 requires listing. Let me know if you find any listed as two raceways with divider installed...