Thayer

I ran into a situation several years ago in which a garage was fed from the house by an overhead service. The previous contractor had used Standard #6 triplex (ACSR messenger) so, no EGC was run between the two buildings. The neutral and ground in the garage panel were then bonded and a single rod was driven. This new electrode was not tied to the house's original grounding electrode. My first thought was that a diffrence in potential would arise. What do you guys think of this situation, how could it be improved overall?

sparks134

I gotta look that one up!!! Just hit 400 posts, yeah!!!

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InPhase277

That was previously legal prior to the 2008 code, if certain conditions are met. No other metallic paths, such as water lines or low voltage cables, can exist between the buildings. And yes, some difference of potential could exist between the two electrodes, but how would one find themselves in contact with both at the same time?

Thayer

I couldn't find a reference in the NEC regarding this situation. There is both a gas line and a bonded telephone cable running between the two buildings. I was originally hired to install the telephone cable between the two , so I know that it is bonded at both ends via the metallic shield. I noticed the power situation later.

nolabama

Cant sleep at night over this one. I would not worry about it. But then again I am a rat hack.

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sparks134

they should change that code back, its a stupid code violation! im gonna make a code proposal next time!!!

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Magnettica

Grounding and Bonding, Article 250, section 250.32.

250.32 (B)(2)

Grounded Conductor. Where (1) an equipment
grounding conductor is not run with the supply to the build-
ing or structure, (2) there are no continuous metallic paths
bonded to the grounding system in each building or struc-
ture involved, and (3) ground-fault protection of equipment
has not been installed on the supply side of the feeder(s),
the grounded conductor run with the supply to the building
or structure shall be connected to the building or structure
disconnecting means and to the grounding electrode(s) and
shall be used for grounding or bonding of equipment, struc-
tures, or frames required to be grounded or bonded. The
size of the grounded conductor shall not be smaller than the
larger of either of the following:
(1) That required by 220.61
(2) That required by 250.122

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Thayer

Somehow I missed that during my brief look. That pretty well sums up the situation.

JohnJ0906

With the other metallic paths between the buildings, that is a violation.
Needs an EGC installed to the garage, and the neutrals/EGCs separated at the garage.
The electrodes do not need to be tied together. (Although they already are, indirectly)

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John from Baltimore
"One day at a Time"
All responses based on the '08 NEC
It's not my fault, it's not my problem, I'm not your solution.

Thayer

Thanks everyone!

Magnettica

That's what we're here for.

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