the straightest answer can only come from your licensed electrician who
knows your code and how it applies to your home/construction
type/soil/climate.
buffalo ny, from a non-electrician: your local electrician must be
asked because some soil and climate conditions at your home address do
not offer to you the otherwise good grounding practices we might
suggest to you. gas: in some repiped areas like here the new
underground gas lines are plastic, and connect to metal to meters
outside the home.
the ground rod idea may not necessarily apply, would you be creating an
unwanted ground loop at the garage?:
http://en.wikipedia.org/wiki/Ground_loop
regarding the rod and bonding and ground loop and more, please read
thoroughly:
http://www.faqs.org/faqs/electrical-wiring/part1/
i was going to quote the parts about grounding and bonding but they are
lengthy;
you will find canada is included throughout the faq.
as electrical codes evolve over the years to make life safer, we
scratch our heads and wish the electrons were more visible as they run
around in our main panel connections.


J wrote:
I've read a number of newsgroup postings and there is so much
disagreement it is hard to get a straight answer. So don't give me the
'asked&answered' response - just save your breath. I might be flogging
a dead horse but here we go....

My house was build in the 50's and all of the original outlets were two
prong with no grounds. At some point in the last 50 years, before I
moved in, someone upgraded the service with a 100 amp panel and added some
more outlets which are grounded. I believe there are no grounding rods,
only the cold water pipe is being used as the grounding electrode. This
is one part that has lots of disagreement but I'm guessing this was up
to code when the work was done. Also, this is not really where my
question lies. The gas line is also bonded to the cold water pipe and
sewer stack in
the basement and there is a jumper over the water meter.

I'm thinking of adding a subpanel in the detached garage. It would be a
fed through #10 THWN (4 wires) from a 30 amp breaker through existing
1/2" EMT. Can is use RW90 in Canada? Since it's a seperate building I
would need to drive a
grounding rod at the subpanel to comply with the code. Can you explain
why this is necessary? If it's the same building then it is not
necessary, right? The neutral and ground at the subpanel would not be
bonded. That part makes sense to me. Also, would the gas line in the
garage need to be bonded to the ground there? This would seem
appropriate to me, but maybe not necessary. For now the ooooold heater
chassis is not grounded.

Thanks for your time,