I acquired a length of 3/8" stranded stainless steel cable (from sailboat
rigging) at a metal recycler. I am planning to use this as my ground "rod" for
my house electrical system. Is there any reason this would not be a good choice
for my grounding system if I run it down 15 feet, well into the water table,
which is 7-10 feet down.
I will do this by using PVC pipe and water pressure to tunnel into the ground,
inserting the cable, then pulling the PVC out.
Should I leave my current galvanized rod connected also if I do this?
Copper at room temperature (300K) is 5.8e7 [1/Ohm/m].
304 SST at room temperature (300K) is 9.8e5 [1/Ohm/m].
So copper is quite a better conductor. Is it enough to matter?
Probably not under benign conditions where only stray leakage currents
flow into the ground system.
If there's a lightning strike or a hard fault from power line to
ground...that's a different story. IIWM, I'd want the best low
Not to mention that code in many areas requires you either prove the
ground resistance is low enought using special equipment, or use a
system of two copper ground rods with specified length, spacing and
Again, IIWM, I'd go with the code approved solution. It's a safety
issue, and a poor ground can prevent surge suppressors and electrical
noise filtering circuits from working properly.
I've never seem a real copper ground rod. Even the copper colored ones I've seen
are merely copper plated steel, and the more common ones are galvanized steel.
Certainly, none of the "big-box" rods are copper.
One of my considerations is to get the rod down into the ground water, and the
commercial 8 foot rods don't do that well. The stainless seemed like something
that would do that, and would last a long time, but I guess I do need to
re-think this on the conductivity basis.
I understand 3/4" galvanized pipe is code approved for ground rods, so maybe I
should get a couple 20 foot lengths of that.
You can get 10' rods and even segmented rods that screw together. 40
foot rods are not all that uncommon in Florida in some special
circumstances like radio towers and toll booths. They join four 10'
sections. You need a drive cap to save the threads for the next rod.
*It may work fine as a grounding electrode, but I prefer to stay with
approved methods. In your case I would be concerned about your connection
to the electrical panel or meter. Usually those terminations are only
approved for copper and aluminum conductors.
After you make your tunnel for the stainless cable to be inserted, what will
cause the tunnel to compress around the cable to make good contact with the
There will be a considerable difference in surface area between what
you get with a 1" or so diameter ground rod and the 3/8" cable. Part
of the benefit of the rod would be, I would think, that his has
substantial surface area.
If for some reason you want to add the stainless cable, yes leave the
current galvanized rod connected. If you are worried your current
ground rod is not sufficient, you may want to update it to latest code.
I *think* that is 2 10' rods 6' apart. If it's new construction the
ground starts out with all the rebar in the footer. It has to be
electrically connected and inspected before the footer is poured. Part
of the rebar, or maybe copper wire from the rebar in the footer is then
attached as your ground without the 10' stakes. (I think that is
right?) I just installed 2 10' ground rods I think 6' apart so I can
have a service going directly to the garage. I'm not sure about all of
that, I was relying on my brother, an electrician, to do the work and I
was the helper. Well not exactly. He let me hammer in the 2 10' ground
rods. (was ready to rent a big hammer drill if needed but it wasn't needed).
To avoid 2 bills which the power co. charges commercial rates for the
2nd one, I'm having a "current transformer" installed out on the pole
with the transformer. From the pole there will be a service going to
the house, and a second one going to the garage. The "current
transformer" monitors both services and powers a meter out on the pole
so I only get one bill. And they won't have to get out of the truck to
read the meter since it will be a newer infra-red optical output that is
read from a hand held unit pointed out of the truck window.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.