Ufer grounds clearly work very well for low stress conditions - static electricity, maintaining a ground reference, communications, etc.
I've always been curious about their effectiveness in a lightning strike scenario, and been unable to find any data on it.
They are good for lightning, that was what the original design was
trying to mitigate (ammo dumps).
The main problem with a Ufer is it needs to be done when you are
laying the foundation. That is now part of the inspection regimen in
The best "made" electrode is a ground ring but most people will
usually not want to do that.
Although you are not allowed to admit it, the absolute best electrode
is a concrete in ground swimming pool.
Ground rings are tedious to install, and with modern copper prices, very
expensive, too. They are usually installed with engineered soil, but
this may vary by location. I imagine Florida is quite the PITA to get
effective Earth bond. I also know that there are some areas, in Florida,
where a bare neutral is not allowed in a metallic conduit.
Same in certain regions of Nevada, California, and Arkansas. Some places
do not allow bare wires sharing a conduit with live wires, period. Some
places really don't have a true, local authority managing certain things.
Sometimes it is scary going into Bubbaville. Electrical code enforcement
is not necessarily universal. Arkansas adopts each new release of code
without a blink. California, well, they like to wait awhile. IIRC, they
were still on the 1993 book in 2002, or had just adopted 1996. I know for
a fact that 1993 was still the gospel in 1999.
So, as a caveat. Check your location's addendums and adoption policies
in regards to code enforcement and localized modifications. For instance,
in Alameda, Ca, it is required to have the meter of a service drop/feed be
a minimum of 75" (IIRC)in areas where there is a walkway or foot traffic
adjacent and parallel to the meter installation. This is the only place
I have ran into this restriction, but...
LOL! What if there is not a concrete footing? As always, local code
trumps NEC. Some locations require a Ufer in conjunction with a ground
rod; vertical. One must remember that all soil is not equal. It not
only goes left-right, forward and back, in all directions from a 2-D
perspective, it also goes up and down. The soil on the surface might
be horrible for obtaining an Earth bond, but 6' down you might find an
excellent strata to accomplish the task.
I've seen locations where the maximum depth allowed is 8' because this
depth was approaching an aquifer (some places are even down to ~6'). It
was impossible to get the soil to provide less than 30 ohms at 6' increments
between ground rods. Needless to say, the cost of that project went up
I didn't do that. I had a copper (clad) ground rod, purchased from a
burglar-alarm supply house, that sold only burglar alarm products)
nailed all the way into the ground minus about 4 inches, and a
separate wire running to the panel. IIRC the rod was 6 feet, but no
less than 4 feet.
4-6 feet? 8 foot minimum with local code specifying diameter, length and
quantity. Some applications allow a 1/2" by 8'. In some applications the
ground rod is allowed to be laid in a trench with proper (direct burial)
connections to rod and access to said connection. Other applications might
require 16', or more, vertical with multiple rods spaced at predetermined
intervals (soil engineered).
It is only a guess, on my part, but it would seem that there was something
not properly installed.
Are you saying there is code for a burglar alarm rod, even though
burglar alarms are not required?
At any rate, this was bought at a professional burglar-alarm only
wholesale store, I didn't ask for a cheap one, I'm sure it was the
only one they sold, at least for homes, and I'm sure whatever they
sold met any code in effect at the time.
Just a guess on your part.
I know this ng. If someone says white, the next person says black.
And vice versa. When I found an extender for my lightbulb so it would
fit in a temporary socket I was using, an extender that had been in my
father's electric parts box probably since before I was born, which I
finally had a chance to use, six people replied, none favorably. The
objections were ridiculous. I didn't say anything then, but this
A rod for burglar alarms is not in the NEC.
In you want all earthing electrodes connected into a single system with
one connection back into the house.
Isolated rods can be at a far different potential (thousands of volts)
than the rest of the electrical system during an "event". The same
principle is why Dufas puts surge protectors at pad mounted a/c
IMHO isolated rods are likely to increase damage.
I'm not familiar with the specifics of electric fences, but the
requirements for grounding a house require much longer rods. And with
house construction people commonly use two rods spaced a distance
apart to improve conductivity.
Leave only enough exposed as necessary to get the cable bonding clamp
on the end of it - an inch or two. And when you say bury, you really
mean how far should you pound it into the ground, right?
I would not worry about the rust as in a month there will be more rust on
YOu should look here about ground rods for the fence.
Unless you have a very short fence one 3 foot rod is not nearly enough. Go
atleast to a 6 foot rod and either a copper coated one or galvinised rod.
On 7/12/2012 10:39 AM, firstname.lastname@example.org wrote:
'Pends on where you're located--if it's only 3-ft, drive most of it,
anyway. If it's enough, you'll know it when you grab 'hold the fence to
test it... :)
The minimum you can get by with (but why worry about it, anyway; it's a
trivial exercise) will depend on how damp a climate you're in so how
much the top of the ground and how deeply the ground dries out to the
point of not having good enough conductivity. Here it needs to be
pretty deep for mid-summer when things get very dry, but 3-ft will
generally work even then.
Secondarily, how much ground you need depends on the length of wire, the
power of the charger and what you're trying to keep in as well as the
ground conditions. If it's very dry the critters don't has as good a
ground, either...when it's damp they'll get a much better jolt.
It would not not be power or wire length, it's high voltage low current.
It's not how deep, but how good a ground. The critter is only on surface
level the current must travel through the ground to get any shock. Nec
guidelines apply to high current safety.
You don't pound ground ground rods unless you hit thin rock, and can get
stuck, and have to cut off and work another if it was not deep enough.
An electrician showed me, at least near Pittsburgh. You pour water down
working the pole up and down with your hand !!! As the pole goes deeper,
add more water. It goes right down. I've done 6 foot rods. One got stuck
couple feet from top. Used sledge to get in a little deeper.
I'm sure I'll get at least one comment on this one !
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