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#96693 - 12/19/05 05:38 AM Sub-Panel
JoeRossi Offline

Registered: 01/31/03
Posts: 26
Loc: Washington, NJ
A contractor runs PCV to a detached building. Proper sizing, three wires and has a ground rod at the building.
I give him a red tag for Article 250.52 (NEC2005) in which a lively debate starts.
When you run a sub-panel 3 wire feed or 4 wire feed. I always run 4-wires plus a ground rod. What do you guys think?
Joe Rossi

2014 / 2011 NEC & Related Books and Study Guides
#96694 - 12/19/05 06:03 AM Re: Sub-Panel
Roger Offline

Registered: 05/18/02
Posts: 1779
Loc: N.C.
Joe, although I would run an Equipment Grounding Conductor because of preference, it is not required if 250.32(B)(2) applicable.

(2) Grounded Conductor Where (1) an equipment grounding conductor is not run with the supply to the building or structure, (2) there are no continuous metallic paths bonded to the grounding system in each building or structure involved, and (3) ground-fault protection of equipment has not been installed on the supply side of the feeder(s), the grounded conductor run with the supply to the building or structure shall be connected to the building or structure disconnecting means and to the grounding electrode(s) and shall be used for grounding or bonding of equipment, structures, or frames required to be grounded or bonded. The size of the grounded conductor shall not be smaller than the larger of either of the following:
(1) That required by 220.61
(2) That required by 250.122


#96695 - 12/19/05 06:09 AM Re: Sub-Panel
JoeRossi Offline

Registered: 01/31/03
Posts: 26
Loc: Washington, NJ
Thank you Roger, have a great day
Joe Rossi

#96696 - 12/19/05 07:59 AM Re: Sub-Panel
Dnkldorf Offline

Registered: 12/12/04
Posts: 1091
Loc: nowhere usa
Roger states that it is not required.. true, but running a seperate EGC would be alot better. It would avoid the whole paralell path thing down the road, when your not there.


[This message has been edited by Dnkldorf (edited 12-19-2005).]

[This message has been edited by Dnkldorf (edited 12-19-2005).]

#96697 - 12/19/05 08:14 AM Re: Sub-Panel
markp Offline

Registered: 04/12/04
Posts: 60
Loc: Kent, WA, USA
What does 250.52 have to do with 3-wire -vs- 4-wire feeders? Why would you give him a violation of 250.52 when you said he had a rod?
Kent, WA

#96698 - 12/19/05 07:07 PM Re: Sub-Panel
HLCbuild Offline

Registered: 12/05/04
Posts: 206
Loc: Herndon,Va USA
Question: As Roger points out, if there is no grounding conductor run with the feeder, the grounded conductor is used to bond metal frames, etc....does this mean that the neutral bar is not insulated/isolated from the ground bar as it would be if this subpanel was located in the main building where the service is located?

#96699 - 12/19/05 11:23 PM Re: Sub-Panel
gfretwell Offline


Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
HC ... Yes, it looks just like a service entrance.
Greg Fretwell

#96700 - 12/20/05 12:15 AM Re: Sub-Panel
e57 Offline

Registered: 05/27/03
Posts: 2837
Loc: S.F.,CA USA
"I give him a red tag.... in which a lively debate starts."

The color red gets most really lively.

So did he get a green one yet, or an orange?
(That is, if there are no bonded metalic paths between buildings or not.)
Mark Heller
"Well - I oughta....." -Jackie Gleason

#96701 - 12/20/05 06:53 AM Re: Sub-Panel
renosteinke Offline
Cat Servant

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
Even the IAEI, when they presented this application to three of it's own experts, got four answers!

Codewise, the guy can probably get away wit only a ground rod, treating the feeder as if it were a separate service.

I am something of a simpleton, and like to consider the "service" to be where the PoCo drops in, with everything from that point to be part of the same system. But I can see where the code might not limit me to that approach.

#96702 - 12/21/05 05:14 AM Re: Sub-Panel
JoeRossi Offline

Registered: 01/31/03
Posts: 26
Loc: Washington, NJ
In my construction days I always ran four wires. I learned fast that just because the contractor does not do it like I do means it is incorrect.
Yes red-tagged always give lively debates but I always call the contractor when it is going to cause extra work and money.
I gave him a white/purple sticker, that is what New Jersey gives out when the final passes.
Thnaks for all your feed back
Joe Rossi

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