Upsizing EGC for voltage drop what about Conduit?

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AC\DC

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So 1/2 emt currently has 3-12 for another circuit one of them is the EGC. I need to run number 6 about 175 to compensate for VD for a RV recep.
I was going to pull the EGC out and use for pull string and just pull two number 6 and just use conduit as EGC.
For VD I know you got to increase EGC (wire) the same you do the phase condutors, Conduit good no matter what correct regardless of VD. I know the EMT is better at clearing a fault then the wire. VD increase just has me guessing I don't see a no in the book
 
Conduit only needs to be sized geometrically for its total wire area applicable to the quantity of wires, and for the mechanics of pulling the wire (e.g. upsizing to avoid jamming). The electrical performance of conduit isn't required to be considered in its sizing. If it is a compliant size geometrically, it is compliant electrically.

The Steel Tube Institute has tables recommending best practices for maximum recommended lengths to use conduit as the EGC, as a function of trade size, after which you'd opt for a wire EGC instead. But this isn't enforceable in the NEC.
 
Carultch said:
Conduit only needs to be sized geometrically for its total wire area applicable to the quantity of wires, and for the mechanics of pulling the wire (e.g. upsizing to avoid jamming). The electrical performance of conduit isn't required to be considered in its sizing. If it is a compliant size geometrically, it is compliant electrically.

The Steel Tube Institute has tables recommending best practices for maximum recommended lengths to use conduit as the EGC, as a function of trade size, after which you'd opt for a wire EGC instead. But this isn't enforceable in the NEC.
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I'd add they don't say instead of but they say an appropriately sized ground in addition allows for more distance from breaker when clearing a fault
 
Also remember you now have four current conductors in a raceway. Is you #6 still good?

2-#12
2-#6

Even if you remove all the number 12 and use 2-#6 the fill allowance changes to 31%

If you look at the table in annex c. It says 2-#6 thhn in 1/2" however a violation in your application.
 
Tulsa Electrician said:
Also remember you now have four current conductors in a raceway. Is you #6 still good?

2-#12
2-#6

Even if you remove all the number 12 and use 2-#6 the fill allowance changes to 31%

If you look at the table in annex c. It says 2-#6 thhn in 1/2" however a violation in your application.
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looking in annex c- 2 can be in a 1/2
 
#6 thhn is .0507x2= .1014
1/2 emt is .122 for 40%

I would have to pull in #14 instead of 12. to make it work.

I was trying to make existing work but now that you caught my mistake on the number 12. I think I just pipe new run. Saved me lol I just submitted a second ago going to pull it back
 
there would still be another 2 wires in them I would just have to take the 12 down to 14. I see what you guys were saying, I described it bad.

Was planning on leaving an existing 20 amp circuit and pull two new wires for total of 4 wires.
Though if I want to now I got to pull in 14awg instead of leaving exiting so now its a pain in the butt.
 
AC\DC said:
there would still be another 2 wires in them I would just have to take the 12 down to 14. I see what you guys were saying, I described it bad.

Was planning on leaving an existing 20 amp circuit and pull two new wires for total of 4 wires.
Though if I want to now I got to pull in 14awg instead of leaving exiting so now its a pain in the butt.
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Pulling in 2 14s would make it legal but you can't do 40% fill on 2 wires
 
ya I understand that never was planning on 2 wire. I remember its a jamming issue. 20 amp multi wire would do what she wants it just for heating her rv and dehumidifier.

Thanks for catching my mistake
 
I got 175 feet that I think about 8% if I remember at max 30 amps.
I know she probably won't ever use max but a multi wire would be better for VD

Ill still have to upsize the multi wire to 10awg
 
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AC\DC said:
I know she probably won't ever use max but a multi wire would be better for VD
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That's what I was thinking in #14. Heck, consider 1" instead of 3/4".

Added: You could add three #10s to two #12s in the 1/2" if the RV can use 120/240v.
 
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LarryFine said:
That's what I was thinking in #14. Heck, consider 1" instead of 3/4".

Added: You could add three #10s to two #12s in the 1/2" if the RV can use 120/240v.
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Don't understand that part??
I was going to upsize the 20 amp multi to 10awg and give her two dedicated 20 amps then she can run cords through the rv lower compartment.
Only way I know an rv uses 240 is on the 50 amps all other conversion are just straight 120

Unless there like a 50 amp conversion to a 14-20r
 
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