Two ground wires

[jlybolt]

Inspected home with meter base outside with ground from meter base to ground rod. Inside of home there was one service panel with the main shutoff and another ground wire run back to the same accorn ground clamp. Why would they have grounded the meter can and service panel?
Is a ground wire from the meter base an acceptable grounding method?
Both meter and panel are within 15 feet of each other. Meter outside and service equipment panel inside.

[Paul W. Abernathy]

James,

Probably due to the LACK of understanding of the NEC requirements I care to venture. The NEC states the GEC can take place at the Meter Can, Service Enclosure or believe it or not at the Service Mast Messenger Wire point.....

My guess is the ground was put in at the meter first ( which our local POCO will not allow...even if the NEC allows it..they are FAST to say it is THERE meter cab and they dont want it in their...)

Then quite possibly the local AHJ said they do not want it in the meter can and want it from the panel...so they just ran another one.....

Can't really tell you why they did both....but to answer your question BOTH locations are accepted as approved attachmenet points by the NEC....as points to which you can connect the GEC to the GE.

[Speedy Petey]

Could also be a POCO requirement.
In my area we did actually have to do exactly what you describe in years past. They then changed it so that NO GEC connections were in "their" meter pan.

[jlybolt]

Paul, service wire messenger point? Can you explain please.

[Paul W. Abernathy]

How about I do ya one better my fine fellow...




(A) Grounding. Services supplied from a utility transformer that is grounded to the earth must have the grounded neutral conductor grounded to a suitable grounding electrode [250.50] in accordance with the following:

(1) Accessible Location. A grounding electrode conductor must connect the grounded neutral conductor to the grounding electrode and this connection can be made at any accessible location, from the load end of the service drop or service lateral, up to and including the service disconnecting means. Figure 250–51

Author’s Comment: Some inspectors require the grounding electrode conductor to terminate at the meter enclosure, while other inspectors insist that the grounding electrode conductor terminate at the service disconnect.

The Code allows this grounding (earthing) connection to be made at either of these locations.

(4) Main Bonding Jumper. When the grounded neutral conductor is bonded to the service disconnecting means [250.24(B)] by a wire or busbar [250.28], the grounding electrode conductor can terminate to either the grounded neutral terminal or the equipment grounding terminal within the service disconnect.

(5) Load-Side Neutral-to-Case Bonding. A neutral-to-case bond cannot be made on the load side of the service disconnecting means, except as permitted for separately derived systems [250.30(A)(1)] or separate buildings [250.32(B)(2)] in accordance with 250.142. Figure 250–52

Author’s Comment: If an improper neutral-to-case bond is made on the load side of service equipment, dangerous objectionable current will flow on conductive metal parts of electrical equipment in violation of 250.6(A). Objectionable current on metal parts of electrical equipment can cause electric shock and even death from ventricular fibrillation. Figure 250–53

(B) Main Bonding Jumper. An unspliced main bonding jumper complying with 250.28 must be installed between the grounded neutral terminal and the metal parts of the service disconnecting means enclosure in accordance with 250.24(C).

OK.....just for short we call the bare wire that supports the service drop the messenger wire...which is also the neutral wire.....or # 1 location in the image I posted....courtesy of Mr. Mike Holt.....

[jlybolt]

Your good, thanks Paul and everyone for your comments.

[Bruce M. Graham, III]

Paul,
Where do you get your illustrations from?
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[Paul W. Abernathy]

Bruce,

I get them from Mike Holt's Website...www.mikeholt.com and the bottom link on the left. You have to have his permission to use them....which I have so I post them alot...lol

[Greg Fretwell]

Pete, it's funny how POCOs work. FPL wants the GEC in the meter can.
I like it that way too since it might shunt lightning to ground before it gets in the house.