"Ed B" wrote in message
...
RBM wrote:
wrote in message
...
On Mon, 14 Jun 2010 20:37:46 -0400, "RBM" wrote:

"Ed B" wrote in message
...
Situation is:
A residential home with a detached garage has a sub panel which is
serviced from a 50A breaker located in the main breaker box. This
service
feed is approximately 20'.
The house has a meter pan/disconnect where the 200A service enters the
house.
The breaker box is approximately 30' from the meter pan. There is a
grounding rod, earthed at the meter pan entrance which goes to the
breaker
panel.
The water lines are bonded.
My main question is should the sub panel in the garage be earthed or
do I
use the ground wire from the main to act as my safety ground like to
carry
currents from a lightning strike to the original earthed point all the
way
across the house by the meter pan.

Since the garage is detached, wouldn't I want to provide a path for
lightning to the closest point?

Any advice will be appreciated. :-)
Thank you
If the feeder to the garage is 4 wire, the grounds and neutrals at the
garage should be on separate busses, and a ground rod or two should be
driven at the garage and attached to the grounding detail.
If there is only three conductors in the feeder from the house, the
neutral
and ground busses should be bonded together in the garage panel, and a
ground rod or two should be driven and attached to the neutral - ground
detail

The 2008 code eliminated the 3 wire feeder entirely. You have to go
the 4 wire route described above.

This is not a new installation. It's existing, and the op doesn't say if
it's 3 or 4 wire. He didn't ask how a new installation should be done.
Thanks to all who responded, your advice is greatly appreciated



It is existing, using a three wire feed. I am installing additional
electrical circuits off of this sub in the garage need to get it
inspected. Once the inspector opens the panel I am afraid he will make me
comply with the 2008 rule change. I am not sure if it is grand-fathered.

If it was done legally to begin with, it should have had ground rods already
.. There is no reason the inspector should have a problem with it since it
was done before the code change.