Art. 250.94 Nec 2008 Compliancy

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Dennis Alwon

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Chapel Hill, NC
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I just got some info That NC will be enforcing this rule and here is what my suppliers have for compliancy.. Is there any other alternatives?? And does this mean we don't enter the meter base and just rely on the screws of this clamp? Seems quite an ugly addition to the service.

47b8da23b3127cceb78f4b064c8600000025100UaNmbRs1Ys
 

Cavie

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SW Florida
That is just one a many ways to acomplish the requirement to provide a lv ground connection. The most common way around here is to stub out a 6" of bare ground from the meter or thru the wall from the panel. Another way is to machine nut and bolt a buss lug to the underside of the metercan. Both are accepted in Florida. the Rube Goldger attachment you posted is usually installed by the Cable and phone guys. If POCO has to remove it to remove the meter, they will not hook it back up.
 

Dennis Alwon

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Cavie-- one has to bond this to the meter pan or panel with a piece of #6 minimum. It also states you must have at least 3 terminals. How does a copper wire cover that? There are exceptions for existind units

For those who don't have the 2008 NEC
250.94 Bonding for Other Systems.
An intersystem bonding termination for connecting intersystem bonding and grounding conductors required for other systems shall be provided external to enclosures at the service equipment and at the disconnecting means for any additional buildings or structures. The intersystem bonding termination shall be accessible for connection and inspection. The intersystem bonding termination shall have the capacity for connection of not less than three intersystem bonding conductors. The intersystem bonding termination device shall not interfere with opening a service or metering equipment enclosure. The intersystem bonding termination shall be one of the following:
(1) A set of terminals securely mounted to the meter enclosure and electrically connected to the meter enclosure. The terminals shall be listed as grounding and bonding equipment.
(2) A bonding bar near the service equipment enclosure, meter enclosure, or raceway for service conductors. The bonding bar shall be connected with a minimum 6 AWG copper conductor to an equipment grounding conductor(s) in the service equipment enclosure, meter enclosure, or exposed nonflexible metallic raceway.
(3) A bonding bar near the grounding electrode conductor. The bonding bar shall be connected to the grounding electrode conductor with a minimum 6 AWG copper conductor.
Exception: In existing buildings or structures where any of the intersystem bonding and grounding conductors required by 770.93, 800.100(B), 810.21(F), 820.100(B), 830.100(B) exist, installation of the intersystem bonding termination is not required. An accessible means external to enclosures for connecting intersystem bonding and grounding electrode conductors shall be permitted at the service equipment and at the disconnecting means for any additional buildings or structures by at least one of the following means:
(1) Exposed nonflexible metallic raceways
(2) An exposed grounding electrode conductor
(3) Approved means for the external connection of a copper or other corrosion-resistant bonding or grounding conductor to the grounded raceway or equipment
FPN No. 1: A 6 AWG copper conductor with one end bonded to the grounded nonflexible metallic raceway or equipment and with 150 mm (6 in.) or more of the other end made accessible on the outside wall is an example of the approved means covered in 250.94, Exception item (3).
FPN No. 2: See 800.100, 810.21, and 820.100 for bonding and grounding requirements for communications circuits, radio and television equipment, and CATV circuits.
 
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Cavie

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SW Florida
Sorry, I did not notice the 2008. We are under 2005 so My guess is bolt on a 3 lug buss bar undert he meter can as some are doing here now.
 

C3PO

Senior Member
Location
Tennessee
The picture looks just like what we were told we are going to start stocking if/when TN adopts the 2008. Ours is made by T&B. There has to be a neater way to do that.
 

Dennis Alwon

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Chapel Hill, NC
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Retired Electrical Contractor
C3PO said:
The picture looks just like what we were told we are going to start stocking if/when TN adopts the 2008. Ours is made by T&B. There has to be a neater way to do that.

That picture is from T&B -- Cat.# IBT1 and IBT2
 

C3PO

Senior Member
Location
Tennessee
Dennis Alwon said:
That picture is from T&B -- Cat.# IBT1 and IBT2

That would explain why they look the same ;)

I would think that some of these meterbase companys would come up with something that's already built in, but I haven't heard of anything. I will try to check with some of our meterbase vendors.
 

Dennis Alwon

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Chapel Hill, NC
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Retired Electrical Contractor
C3PO said:
That would explain why they look the same ;)

I would think that some of these meterbase companys would come up with something that's already built in, but I haven't heard of anything. I will try to check with some of our meterbase vendors.

The idea is that they are not to be built in. How would the cable or phone people connect to it if it were in the meter? I think this ruling is in part to keep phone and cable of our GEC to the ground rod. Why. I am not sure.
 

C3PO

Senior Member
Location
Tennessee
Sorry, I did not make myself clear. I meant built in but accessible form the outside. Like some sort of external lugs underneath the can or something (but out of the way of KO's)
 

infinity

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New Jersey
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Journeyman Electrician
Hopefully the people who make meter pans will incorporate this setup into the pan itself.
 

raider1

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Location
Logan, Utah
infinity said:
Hopefully the people who make meter pans will incorporate this setup into the pan itself.

Agreed, it shouldn't be hard to incorporate an external ground bar with 3 terminals on the outside of the meter pan.

Chris
 

hillbilly

Senior Member
raider1 said:
Agreed, it shouldn't be hard to incorporate an external ground bar with 3 terminals on the outside of the meter pan.

Chris

I have a suspicion that the reason is...

It would cross the line between the meter pan being service equipment and the external ground bar being non-service related.

It may expose the meter pan manufacturer to liability if a ground fault or lightning strike should damage persons or property....the ground bar would then be in the mix....kinda a CYA sorta thing....maybe...

Just my thoughts

steve
 
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