John Ross wrote:

bud-- wrote:
John Ross wrote:

But as far as these wire sizes everyone is throwing around: is that
required or suggested? I hear this size 6 mentioned. Is that the code
from the rod to the panel or is that just suggested. Also, does that
change with the size of the service (this is 100 amp)? I think this
latest electrician said something about size 10 or 8.

Connecting ground rods minimum #6.

Services - depends on service conductors.
Generally 100A #6 is minimum used (can be #8 but the requirements on
installation are very restrictive).
200A service #4
#4 may be used instead of #6 because #6 also has some limitations on use
without 'protection'.
snip
The inspector can also allow variances.
In your case, the jurisdiction or inspector allows connecting the added
receptacle ground wires anywhere on the water pipe while the NEC now
allows that connection only to the first 5 ft of the water pipe. [If the
wire from electric service to water pipe electrode is not in the first 5
ft, as was permitted in the past, it does not make sense to connect
added ground wires in the first 5 ft. And the added ground wires can
usually be more conveniently connected elsewhere in the electrode system.]/snip

I spoke with the electrician today and he said he would use #8 wire
(he said that was for 100 amp panel). Not sure what you meant by "very
restrictive" in using that, I doubt he would do anything different.

2005 NEC 250.64-B "Securing and protection against physical damage"
"Grounding electrode conductors smaller than 6AWG [#8} shall be in rigid
metal conduit, intermediate metal conduit, rigid nonmetallic conduit,
electrical metalic tubing, or cable armor."
All of them are a form of pipe (some are light weight pipe) except cable
armor which is a spiral metal protection like BX. If the conductor is
run through ferrous tubing/pipe there are additional requirements that
directly or indirectly bond both ends of the pipe to the grounding
conductor. If you use one of the required protection methods #6 should
be cheaper.

"A 6AWG grounding electrode conductor that is free from exposure to
physical damage shall be permitted to be run along the surface of the
building construction without metal covering or protection where it is
securely fastened to the construction; other wise it shall" use one of
the protective methods above.

"A 4AWG or larger copper or aluminum grounding electrode conductor shall
be protected where exposed to physical damage."


Also, I am not so sure anymore that my city does allow the water pipe
connection for add on grounds. In any event, did I understand you
correctly that since the original "bonding" to the pipe was not
required to be 5 foot from entrance, and since it is still all metal,
it doesn't make sense to redo it to within 5 feet (if not required)
i.e. just leave that alone until plastic pipe enters the picture?

My intent was if the electrode connection to the water pipe is not
within 5 ft of the building entrance, the restriction of connecting your
added receptacle ground wires within 5 ft of the entrance does not make
sense. I would usually split bolt the receptacle ground wires to one of
the heavy grounding electrode wires anyway.

If the electrode connection to the water pipe is not withing 5 ft of the
entrance it is safe as a grounding electrode as long as the metal water
pipe is intact. Your call whether you move the connection.

[Note that when w_ talks about "bonding" the water pipe, it is not for
using it as a grounding electrode, but is the connection required if the
water service is plastic.]


I hope this doesn't open up a new can of worms, but I remembered that
the way they did these houses, they didn't have a ground bar in the
panel--the grounds are connected to the neutral bar. I asked him about
that and he said he would just connect the new ground connections to
the neutral bar also and "that was legal." Do you see a problem with
that?

At the service panel only (not downstream subpanels) the neutral and
ground are connected. The neutral bar is usually insulated from the
enclosure, but they should [almost] always be connected together at the
service panel. The connection is often by a screw that goes through the
neutral bar and screws into the enclosure behind - not at all obvious.

The neutral-ground connection at the service is part of providing a low
resistance metal path for short circuit currents to trip breakers. The
path is ground wire to neutral-ground bond to service neutral to
transformer.


--
bud--