Grounding electrodes at outbuildings

[Joe Funderburk, CMI]

Are you looking for this at outbuildings, shops, detached garages, etc.?


2009 IRC E3607.3 Buildings or structures supplied by feeder(s) or
branch circuit(s). Buildings or structures supplied by
feeder(s) or branch circuit(s) shall have a grounding electrode
or grounding electrode system installed in accordance with
Section E3608. The grounding electrode conductor(s) shall be
connected in a manner specified in Section E3607.3.1 or, for
existing premises wiring systems only, Section E3607.3.2.
Where there is no existing grounding electrode, the grounding
electrode(s) required in Section E3608 shall be installed.
Exception: A grounding electrode shall not be required
where only one branch circuit, including a multiwire branch
circuit, supplies the building or structure and the branch circuit
includes an equipment grounding conductor for
grounding the noncurrent-carrying parts of all equipment.
For the purposes of this section, a multiwire branch circuit
shall be considered as a single branch circuit.

IRC Commentary:
Where two or more buildings are supplied from one
service, each building must have a grounding electrode.
For example, a dwelling has a service supplied
from the power company to service equipment on the
outside of the dwelling and has two 2-pole circuit
breakers as main service disconnects. One 2-pole circuit
breaker serves a feeder run to the panelboard inside
the dwelling, and the other serves a feeder run to
a panelboard at a separate workshop building 100 feet
(30 480 mm) away from the dwelling. Both the dwelling
and the workshop must have a grounding electrode as
described in Section E3608. If there is no grounding
electrode at the workshop, one of the grounding electrodes
listed in Section E3608 must be installed. A
ground rod, concrete encased electrode, or ground
ring could be installed. If water is supplied to the separate
workshop building through metal pipe, an underground
metal water pipe could serve as the grounding
electrode. This section states that the grounding electrode
at the separate building must be connected in
the building disconnecting means in one of the ways
described in the two sub-sections that follow. Note that
Section E3607.3.2 applies only to existing premises
wiring systems. A separate building must have a main
disconnect and not simply a panelboard. A main disconnect
could be a main circuit breaker in the
panelboard that would disconnect all the power to the
panelboard.

A grounding electrode is not required in a separate
building if it is served by only one branch circuit. If a
separate building supplied by only one branch circuit
does not have a grounding electrode, it does not have
to have a ground rod installed. If a metal underground
water pipe is already installed at the building, it does
not have to be bonded to the equipment grounding
conductor of the one branch circuit. A building like a
small tool shed, for example, may have only a light and
receptacle. The equipment grounding conductor run
with the branch circuit conductors is sufficient to
ground any equipment for this separate building. Of
course, a receptacle in a tool storage shed or accessory
building at grade level would require ground-fault
circuit-interrupter protection, but, the grounding conductor
need not be connected to a grounding electrode
such as a ground rod.

[Sean Fogarty]

SO in lamens terms, if you have a sub panel in your garage, then it needs a grounding electrode.

[Joe Funderburk, CMI]

Originally Posted by sfogarty

SO in lamens terms, if you have a sub panel in your garage, then it needs a grounding electrode.

Unless there is only 1 branch circuit (outlets and lights, for example).

[Joe Funderburk, CMI]

I have only seen a grounding electrode at an outbuilding once in 5 years.

[Sean Fogarty]

I would agree with you. What do you think people will say when you try to make them fix it???

Also are you sure it is a manditory requirement in your area?

[Joe Funderburk, CMI]

Originally Posted by sfogarty

I would agree with you. What do you think people will say when you try to make them fix it???

Also are you sure it is a manditory requirement in your area?

If it's an existing building without a 4-wire feeder, this code applies:

http://www.nachi.org/forum/f19/groun...ildings-56130/

Regardless, unless it's a single circuit, all outbuildings require a grounding electrode per the 2009 IRC. Read the commentary in the above link for existing buildings.

[Sean Fogarty]

Even if the stste does not recognize this adoption?

[Joe Funderburk, CMI]

Originally Posted by sfogarty

Even if the stste does not recognize this adoption?

The IRC is not applicable if it's not adopted by your local government or state.

[Sean Fogarty]

SO I guess the turning of the blind eye will continue for me

[Joe Funderburk, CMI]

Originally Posted by sfogarty

SO I guess the turning of the blind eye will continue for me

Is the NEC applicable where you live? The electrical section of the 2009 IRC comes from the 2008 NEC.

[Jeffrey R. Pope]

Originally Posted by sfogarty

SO in lamens terms, if you have a sub panel in your garage, then it needs a grounding electrode.

If the garage is detached, yes.

I have always tried to confirm that detached structures have their own GES. If I cannot confirm it, or it isn't present, it goes in the report as a necessary correction.

[Sean Fogarty]

Originally Posted by jfunderburk

Is the NEC applicable where you live? The electrical section of the 2009 IRC comes from the 2008 NEC.

In some areas of East TN I don't think they know what the NEC is

[Joe Funderburk, CMI]

Originally Posted by sfogarty

In some areas of East TN I don't think they know what the NEC is

If you do, you should educate them via your reports.

[Sean Fogarty]

Originally Posted by jfunderburk

If you do, you should educate them via your reports.

I am glad you are enjoying all the new found books at you job Joe.

[Joe Funderburk, CMI]

Originally Posted by sfogarty

I am glad you are enjoying all the new found books at you job Joe.

I'm studying for my ICC electrical exam. Learning all kinds of interesting stuff I never realized!