Service ground

[Bungalows]

Jerrry,
I had a house today with the meter (overhead service, driven ground rod and grounding conductor going into the meter can)on one end of the home and the service equipment on the opposite end (60') 2 hots and a neutral no ground at service panel. It is my understanding that the service panel should have a ground run to it if it is more than 6-10' from the meter, is that correct? and what is the code site for that.
Thanks

[Jerry Peck - Codeman]

Hi Bungalows,

This is what I think you are thinking of, a mixture of two things.

The first thing which needs to be addressed are the following:
- Do the service entrance conductors run from the overhead service and meter location to the service equipment location: a) through the house, b) through the attic, c) under the house (crawl space), d) under the house (slab), e) over the roof, or f) around the house?
- If the answer to the above is a), b), or c), and the conductors are not in a raceway and are not encased in concrete not less than 2 inches thick all the way around the raceway, the conductors are considered to have entered the structure at the point where the raceway enters the structure at the area stated in a), b), or c).
- If the answer to the above is a), b), or c) and the conductors are in a raceway and are encased in concrete not less than 2 inches thick all the way around the raceway, the conductors are not considered to have entered the structure at the point where the raceway enters the structure at the area stated in a), b), or c). The conductors are considered to have entered the structure at the point where the conductors emerge from that raceway which is embedded in concrete within the structure.
- If the answer to the above is d), e), or f), then the conductors are not considered as entering the structure until the conductors get around the house to the point were the service equipment is located and, if the service equipment is inside, the conductors are considered as entering the structure at the point where they actually enter the structure. If the service equipment is located outside, then the service entrance conductors would not be considered as having entered the structure, the service entrance conductors just ran around the house to the service equipment.

While the above may seem complex initially, when a), b), c), d), e), and f), are addressed individually, and the non-applicable ones discarded, the installation will become simple and apparent, and, depending on which the installation is, the requirements applicable to the installation will be different.

Let's presume the installation is a), b), or c), as the same requirements will apply to all of them.

Here is the installation as presumed: The overhead service and meter is on one end of the house, the service entrance conductors run from the meter can to the service equipment located in the house in conduit which goes up the wall above the meter to the attic (or down to the crawl space, same thing), the conduit runs across the attic (or crawl space) then turns and runs into a wall where the service equipment is located 60 feet from the meter.

The raceway is metallic and is serving as the equipment grounding conductor between the meter and the service equipment, or is non-metallic and is not serving as the grounding conductor. Making presumptions here as we go along in the example to fill in the missing information which was not given. Being as these are service entrance conductors, no separate equipment grounding conductor is required. The raceway contains 2 hots, and the grounded neutral conductor which is serving as both the neutral and the grounding conductor, which is allowed as these are still service entrance conductors.

Now, as stated above, two problems come into play.

- 1) The disconnect is required to be located at the point of entrance of the service entrance conductors into the structure, which is where the conduit turns into the wall and goes into the attic/crawl space. The service equipment is located 60 feet away. This is not allowed as it is not in any stretch of imagination "nearest the point of entrance of the service conductors".
- - From the 2008 NEC. (bold and underlining are mine)
- - - VI. Service Equipment — Disconnecting Means
- - - - 230.70 General.
- - - - - Means shall be provided to disconnect all conductors in a building or other structure from the service-entrance conductors.
- - - - - - (A) Location. The service disconnecting means shall be installed in accordance with 230.70(A)(1), (A)(2), and (A)(3).
- - - - - - - (1) Readily Accessible Location. The service disconnecting means shall be installed at a readily accessible location either outside of a building or structure or inside nearest the point of entrance of the service conductors.

- 2) The grounding electrode conductor is required to be connected to the grounded service conductor (neutral), between the load side of the service drop to the bus to which the grounded conductor is connected at the service equipment, in an accessible location. Being as many AHJ do not consider the meter as an accessible location because the power company seals it up after installing their meter, the next accessible location is typically the service equipment itself. This means the grounding electrode conductor would be required to run from the driven ground rod all the way to the service equipment.
- - 250.24 Grounding Service-Supplied Alternating-Current Systems.
- - - (A) System Grounding Connections. A premises wiring system supplied by a grounded ac service shall have a grounding electrode conductor connected to the grounded service conductor, at each service, in accordance with 250.24(A)(1) through (A)(5).
- - - - (1) General. The grounding electrode conductor connection shall be made at any accessible point from the load end of the service drop or service lateral to and including the terminal or bus to which the grounded service conductor is connected at the service disconnecting means.
- - - - - - FPN: See definitions of Service Drop and Service Lateral in Article 100.

Where I believe you are combining the two different issues is your 6 feet to 10 feet from the meter thinking. That allowable length is based on where the meter is located and where the service entrance conductors enter the structure. Here are a few examples to illustrate the different allowable lengths and where those came from:
- Meter on exterior block wall with service equipment on interior of block wall directly inside the meter. The service entrance conductors "enter the structure" where they come out of the meter can and enter the block wall. The block wall is typically 8 inches thick, the conductor typically run up to the top of the service equipment, about another 3 feet, and then allowing for proper bending radius, etc., the total length of service entrance conductors inside the structure is about 5 feet to 6 feet. A 2x6 frame wall is not going to reduce that as the frame wall will require sheathing and siding, so the total thickness will be about the same, maybe even slightly greater than a block wall with 1/2 inch of stucco on it.
- Meter on exterior block wall with service equipment inside in an interior wall with the service entrance conduit coming up through the concrete floor slab. Typically the service equipment enclosure will be mounted as such a height which would require the service entrance conductors to enter the structure at the 2 inch down point in the concrete slab, extend up 6 feet 7 inches to the service disconnect, with additional length required for proper bending, for an approximate length of 8 feet to 10 feet of service entrance conductor inside the structure.

Remember when breaking the above down into separate options, and discarding the options which are not applicable, what remains will be a simple description of what you have, only I did not have enough information to condense the requirements do to only what is applicable to your installation.

I believe you will find the answers to your asked and unasked questions to be: that distance from the meter to the service equipment is not allowed as the service entrance conductors are too long within the structure, and, the grounding electrode conductor from the ground rod needs to go to the service equipment 60 feet away.

Hopefully that information helps.

Codeman

[Bungalows]

Thanks Jerry, this was in the attic with no conduit. I find this about 20% of the time.
awsome site keep it up

[Jerry Peck - Codeman]