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Old 11-19-2010, 01:49 PM   #1
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Do I need another grounding rod for this?


I am about to start the prep work for a rural house I will be building over the next year. The PoCo just installed my permanent service, it's a pretty much just a short wooden post with an attached meter socket box, situated next to a green transformer cabinet fed by an underground line. The meter socket connects to the transformer via PVC conduit that goes down into the ground. My intention is to install an outdoor main breaker load center with a couple breakers, and a pair of GFCI outlets. (Or GFCI breakers and standard outlets, either way). There is nothing else at the site so it will just be these two circuits for the next many months. I know I need a good ground, but I see inside the cabinet there is already a bare copper ground coming from the PoCo. (Which seems to be tied to the heavy neutral cable also coming from the PoCo). I assume there is a ground rod buried somewhere nearby as the transformer itself is positioned directly next to the post.

What does a guy normally do in this situation? Would I have to install my own ground rod just for these two outlets? Or can I tie into the ground that's already in the meter socket junction box?
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Old 11-19-2010, 02:52 PM   #2
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Yes, you must install your own grounding electrode system. It will be bonded in your disconnect.
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Old 11-19-2010, 07:30 PM   #3
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Quote:
Originally Posted by nap View Post
Yes, you must install your own grounding electrode system. It will be bonded in your disconnect.
The PoCo-provided meter socket has a DPDT lever for selecting between the main power source and "aux" for a potential generator, as well as center-off for no supply even if a generator were to be connected. Because of this, would I be allowed by NEC2008 to use on the post an outdoor main-lug load center without a main breaker, as the meter socket already provides for a disconnect (granted it's not a current limiting disconnect)?
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Old 11-19-2010, 08:25 PM   #4
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Um, I don't know. I have never seen such an installation by the POCO. That disco is technically the first disconnect so that is where your grounding electrode system should be bonded and then a 4 wire feeder to the panel with separate neutral and grounding systems.


Quote:
would I be allowed by NEC2008 to use on the post an outdoor main-lug load center without a main breaker
If just a switch, you have to have OCPD so no, you would have to have a panel with OCPD.

can you take a pic of this? I am curious about it.
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Old 11-19-2010, 08:31 PM   #5
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The panel is one of these models:
http://www.ronkelectrical.com/meter_rite_socket.html

The lever has three positions: MAIN, AUX, and center-off. It's a very large heavy duty mechanical switch inside connected to that external lever.

I would like to mount an outdoor load center and a couple outlets below it for construction purposes. I'm just wondering if I would need to have a load center with a main breaker. The reason I'm interested in a main-lug load center is because of the wider selection of outdoor grade panels.
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Old 11-19-2010, 08:40 PM   #6
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wow, I've never seen them before. About all we have around here is Milbank. I looked for suppliers and they list several in the next town over.

Dang, around here, the POCO doesn't even install the meter base. That is customer supplied and installed.

from what I can see, they would fit the requirement for the first disco so the neutral bond would be in the disco portion of that unit. You would need a 4 wire feeder to a panel WITH overload protection.

Is the grounding conductor you spoke of feeding into that disconnect unit?
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Old 11-19-2010, 08:57 PM   #7
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Quote:
Originally Posted by nap View Post
from what I can see, they would fit the requirement for the first disco so the neutral bond would be in the disco portion of that unit. You would need a 4 wire feeder to a panel WITH overload protection.

Is the grounding conductor you spoke of feeding into that disconnect unit?
Yes, the PVC conduit coming from the transformer cabinet contains an insulated neutral and a heavy braided bare copper ground. The ground leads up into the sealed portion of the enclosure, where I presume its connected to the neutral as there is no visible ground bar anywhere. Then again, perhaps the bare copper is just there to bond the metal transformer cabinet to the metal meter base?

Just to explain where I'm coming from, I have watched and helped with several family member's own personal remodeling projects over the years. All have been either meter base on the outside of the house with the main load center on the opposite side of the wall.... or rural meter on a pole about 75 feet from the house with a 200A breaker below the meter base, and a 200A Main Breaker load center in the house. My own project is the first where I've ever dealt with the issue of outlets on the outdoor pole/meter base demarcation point.
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Old 11-19-2010, 09:05 PM   #8
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the outside/remote panel isn't really anything special. It is treated just like any other panel for the most but obviously has to be at least 3R rated.

Quote:
Yes, the PVC conduit coming from the transformer cabinet contains an insulated neutral and a heavy braided bare copper ground. The ground leads up into the sealed portion of the enclosure, where I presume its connected to the neutral as there is no visible ground bar anywhere. Then again, perhaps the bare copper is just there to bond the metal transformer cabinet to the metal meter base?
There is a neutral terminal in the disco where you can access it, right? Code requires that the EGC, GEC, and neutral be bonded in the first disconnect so I would say you need your own ground rods and GEC.

I would contact your local inspector and possibly the POCO on this though. It is just strange enough that I do not want to direct you down the wrong road. Maybe there is something going on in this installation I am not considering.
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Old 11-27-2010, 03:03 PM   #9
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Quote:
Originally Posted by nap View Post
the outside/remote panel isn't really anything special. It is treated just like any other panel for the most but obviously has to be at least 3R rated.

There is a neutral terminal in the disco where you can access it, right? Code requires that the EGC, GEC, and neutral be bonded in the first disconnect so I would say you need your own ground rods and GEC.

I would contact your local inspector and possibly the POCO on this though. It is just strange enough that I do not want to direct you down the wrong road. Maybe there is something going on in this installation I am not considering.
I was finally able to talk with someone at the POCO willing to say more than "we can't give advice". I thought I would share it here.

I am to install my own disconnect outside of the meter base. Even though the meter base has a DPDT switch, I'm told it doesn't count as the main disconnect as there is no center-off (I misread the specs and was wrong about that). In the event of a generator connected to the AUX bus, there would be no way to cut the power without disconnecting the generator and throwing the switch to AUX.

I am to treat the POCO-provided meter base / DPDT switch as just a plain meter base. I am to bond my grounds in my external disconnect, not in the DPDT portion of the chassis as the lugs located in there are for neutral only. I didn't notice this before, but the POCO's ground and neutral are not bonded in the DPDT portion of the chassis, they apparently are bonded somewhere in the sealed meter area.

So I guess no shortcuts for me! I will have to install a right and proper main disconnect and go from there. Glad I checked before I started work and wasted the inspector's time.
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Old 11-27-2010, 04:49 PM   #10
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thanks for coming back with that. Sure seems like an odd situation. I can't figure out what the purpose of the installation is. I cannot see them allowing you to connect a generator through that from what you have said about it. You cannot connect a generator through it because it is before your first disconnect.

Just not seeing the purpose at this point.
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Old 11-27-2010, 05:17 PM   #11
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I'm not quite sure either. I think I'm just going to set up an outdoor disconnect, load center, and in-use covered GFCI outlets for construction. When it comes time to connect the new house, I'll revisit the generator connection options then.
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Old 11-27-2010, 05:33 PM   #12
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This arrangement is almost identical to how my new service is set up except for the switch - my switch is DPST.
My meter is about 80' from the house and my disconnect is at the house inside the main panel. I only have two hots and a neutral running between the meter and the main panel. My panel ground is a concrete encased electrode.
I think what makes the difference is these lines, from the meter to the house main, are unfused lines. My PoCo provided the dual meter pedestal.
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