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Detatched structure with two 10-2 feeds

electriclese

Bronze Member
Joined
May 24, 2013
Messages
54
Location
Colorado
Ok I have a home owner that did his own work and now wants me to fix the mess. There was a barn but it burned down (imagine that). He saved the two underground feeds, and built a new metal building that's used to store farm equipment and now he wants me to dig up the feeds inside the new building and feed lighting and receptacles. Knowing that I cannot run two feeds, is it acceptable for me to utilize the black conductor from one feed to make a three wire feed out of this conundrum, tagging it with red tape and terminating at main panel using double pole 30-amp breaker? As both are run in seperate parallel raceways underground using 10-2 UF cable in EMT I would ensure both have ground conductors terminated at EGC and I plan to install a disconnect and a 6 six space loadcenter in the new detatched structure. I also plan to sink two 8' x 5/8" grounding electrodes spaced 6 feet apart by this structure tied with #6 and terminated at EGC. No livestock issues so I dont see any need to run a bunch of GEC in the slab to equalize it with any transient neutral voltages. All receptacles installed in detatched structure will be GFCI protected.

Anyone see problems with my logic? Any requirement for arc fault protection on this feed?
 
In looking at the 2006 IRC, Section E3802.2 = Garage and accessory building receptacles,

the GFCI protection rating would be required only if the detached garage is unfinished

on the interior. Is your application finished or unfinished? No arc fault protection required

on your feeder!

.
 
electriclese said:
Knowing that I cannot run two feeds, is it acceptable for me to utilize the black conductor from one feed to make a three wire feed out of this conundrum, tagging it with red tape and terminating at main panel using double pole 30-amp breaker?
Nope

300.3(B) Conductors of the Same Circuit. All conductors of

the same circuit and, where used, the grounded conductor

and all equipment grounding conductors and bonding conductors

shall be contained within the same raceway, auxiliary

gutter, cable tray, cablebus assembly, trench, cable, or

cord, unless otherwise permitted in accordance with

300.3(B)(1) through (B)(4).
 
: - :

I simply have to return the favor chris,

...but, "things kinda slow over at Mike Holt's Forum ?" :D

: - :
 
globe trekker said:
In looking at the 2006 IRC, Section E3802.2 = Garage and accessory building receptacles,the GFCI protection rating would be required only if the detached garage is unfinished

on the interior. Is your application finished or unfinished? No arc fault protection required

on your feeder!

.
It is unfinished, partial slab (rest is gravel).

300.3B - that's what I was looking for. I knew I had read about some conflict long ago when I saw the existing feeds in two 3/4" emt. Looking at my 2011 book here at home it is very clear. Thanks - page tagged and 300.3b highlited.

You guys rock.
 
I might disagree here as 300.3(B)(3) would seem to be the exception. If this is 10/2 uf and I would bet they are run together in the same trench and I see no difference in this then running 3 individual direct burial conductors in a trench. This is a non ferrous run and although strange I think it would be compliant depending on how it was dealt with where it came out of the ground.

I would bet the cable isn't buried deep enough but..........
 
jar546 said:
cable assemblythink about it
Yep. The term same raceway makes it very clear.

Looks like he gets one 20 amp feed for lighting and receptacles. He doesn't want to pay to have a new feed trenched in.

Thanks again.
 
Again I respectfully disagree. I can run nm cable indoors and have the neutral run a different path. 300.3(B)(3) clearly allows this. It will create electromagnetic field's but cables underground running next to each other will not create the electromagnetic field's. I really don't believe this is a violation.
 
Maybe I am confused but did I read this pair of UFs was in a 3/4" raceway? If so, will they pull out? (pulling in 4 THWNs behind them).
 
gfretwell said:
Maybe I am confused but did I read this pair of UFs was in a 3/4" raceway? If so, will they pull out? (pulling in 4 THWNs behind them).
I missed the EMT. I stand corrected. Why would anyone run UF inside EMT instead of PVC. Once a ferrous raceway is involved then that changes the situation.
 
We still don't know if the cables are in close proximity in the same trench or not which is the key to answering this question. Until they prove it is then this is a no go.

(I) Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors shall be installed in the same raceway or cable or shall be installed in close proximity in the same trench.
 
jar546 said:
We still don't know if the cables are in close proximity in the same trench or not which is the key to answering this question. Until they prove it is then this is a no go.(I)Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors shall be installed in the same raceway or cable or shall be installed in close proximity in the same trench.
If they are in emt then it doesn't matter about the proximity- it's a no go
 
Dennis said:
I missed the EMT. I stand corrected. Why would anyone run UF inside EMT instead of PVC. Once a ferrous raceway is involved then that changes the situation.
The same person used non sealing fittings on the emt and they secured above ground portions of the emt to the home using drywall screws. I told him it would come down when rust hits those screws and good thing he used UF as the EMT is probably saturated from their irrigation. As far as burial depth, I hesitate to speculate but I bet it's not 18" though.
 
Underground raceways are usually full of water but EMT is not usually that durable underground anyway, at least not in SW Florida. It may just be a trail of red dust.

If it is still a complete raceway system and he can get the UF to move, tie four THWN (in an appropriate size) on the end and pull it through. Problem solved.

He might have to suck some Yellow 77 through the EMT with a vacuum to get things moving. At least feeling the suction at the other end will go a ways toward proving the raceway is sound and not rusted away.
 
All great thoughts. I will pull a vacuum on them and see if either raceway is intact. I hope they used wide sweep bends. It is 115' long. Pretty long for 3/4" with 12-2 UF in my opinion.
 
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