Thank you William. I see I need some corrections in the finer
details of my recollections... It has been 20 years since I let
my license lapse.

In my local code, nothing but the UFER is acceptable anymore
since about 1995. Small commercial buildings can still use a
grounding rod, but residential buildings are all UFER.. The
footing that contains the UFER has to be at least 10 feet in
length, 2 feet wide, and 24 inches under the surface of the
ground. The copper wire can be looped in the footing, as long
as it is more than 12 inches apart, and 6 inches from the
surface of the concrete at any point. It is probably 4 gauge,
but 6 came to mind for some reason... CRS no doubt.

Some localities have such poor soil for grounding that nothing
short of a full ground plane under the building will do. Arizona
comes to mind.

My house has no concrete footer. It uses prefab concrete walls
that are preinsulated, and set on 6 inches of tamped #8 crushed
stone. I complained about the UFER grounding requirement to
the county engineer, and he said he had zero latitude in making
substitutions for the requirement. The reason he gave for the
new (then) requirement was a combination of NEC, and the trouble
that they have had with bad connections and damaged grounding
wires with the ground rod method. I had to pour a special
2 foot by 10 foot footing just for the UFER ground.

Water pipe grounds are frowned upon because it is standard utility
practice today to use plastic tubing from the house to the meter
head.... In the house too, with CPVC. Using gas pipe as a
ground is just stupid. But I have seen it done.

Otherwise, I think what I said is true.

-Chuck Harris

William Ray wrote:

This is supposed to be a discussion about Tek scopes, and I don't mean to be rude, but safety is kind of important, and so its good to be correct about what's acceptable/unacceptable for wiring practices:

It is quite clear from the 2017 NEC, that water pipes, ground-rods, etc. are still permissible in the USA. I'm not sure if gas pipes ever have been.

"Ufer" grounds require considerably more than 8-feet of conductor in the concrete. 6 AWG is not adequate for a Ufer.

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