On a single phase residential service, no disco, do you pull a 3 wire service entrance or a 4? I always thought that the panel or disc. was the first stop, allowing you to use the 3, and any other sub after that required the 4 wires.
Thanks, John
If I'm reading your post correctly (that may be doubtful) you would run 3 conductors to the service disconnecting means. After that, any feeders must have an equipment ground (4th wire or metal conduit).
Tom
You read it right. In this case there is only a 200 amp meter, and a 200 amp main breaker in the panel box, no 'knife' switch. We have always ran 3 wires from the meter directly to the panel in this case when there was no disco between the two.
Local POCO won't allow a ground wire between the two, just a properly bonded conduit in RMC.
Exactly. You absolutley don't want a ground between the meter and main.
Is there any article in the nec refering to this? I can't find it.
Thanks again.
John
Article 250 would be a likely starting place.
Start here:
http://www.mikeholt.com/freevideo.php?id=GVB2005 Good luck!
Thanks, thats a great site. To bad my internet is running like dial up, and has been for the last few days. I guess to sum it up, is there any new revisions, or any thing wrong with runninga 3 wire seu with a bare grounded conductor from the meter base to the panel box with a main breaker? I bidded on these houses, and now the inspector says I have to run a 4 wire ser cable, almost twice the cost per foot. I would then need to seperate the ground wires from the neutral wires in the panel box to keep from a parrallel.
John
If this is a typical "riser -to meter -to main panel" setup your inspector is nuts.
Ask him where exactly he expects you to terminate the extra wire.
I could be wrong (it wouldn't be the first time), but it seems that inspector wants you to use the 4-wire because the 200amp main panel isn't at the nearest point of entrance as required by article 230.70 (A) (1).
Also, the grounded conductor isn't the bare conductor, that's the bonding conductor. The grounded conductor is commonly referred to as the neutral conductor.
You will have to install a service disconnect (main disconnect) at the nearest point of entry, or beneath the meter on the outside of the house. This is where your GEC (article 250.66) EGC (article 250.122), and GROUNDED conductor (article 200) from the POCO will all be bonded together to create a solidly grounded electrical system.
I hope I have helped.
Good luck!
--Ron
[This message has been edited by ShockMe77 (edited 01-04-2006).]
Well this is very interesting. The only reason I could see for the inspectors reason would be if you were running from a disconnect to a main lug panel, you would use ser. But you're not. Even if the panel is too far away from the entrance, I think you would be required to install a disconnect before the panel, not simply run ser instead of seu. I don't get it.
I don't do a lot of residential. But when I uppgraded my service to 200 amp, I had to mount a disconnect by the main. I had to run a #6 bare solid CU from the meter (where the N & G bonded together), to the disconnect, and to each of the ground rods, all in one piece. I had to have 2 ground rods 10' apart.From the disconnect to the sub panel was 4 conductors. Anything other, and they would not pass it.
Bob, no disco required, but he wants ser. I dont get it either.
Speedy, EXACTLY. I asked him where to terminate the wire, and he told me to use a double lug, or a single lug tapped to the meter can. I think he is pulling this out his butt. I am going to ask him for written documentation in his municipality that states this requirement. I hope I don't p!$$ him off to bad, but oh well.
[This message has been edited by scjohn (edited 01-05-2006).]
[This message has been edited by scjohn (edited 01-05-2006).]
I would ask him for documentation.