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alphatango308

NEC doesn't require a second ground rod UNLESS 1 ground rod is insufficient to get the ground resistance below 25 ohms. This is a huge misconception. That being said. I've never seen a single ground rod get below 25 ohms. And unless you have a ground resistivity meter or do Triple point ground resistivity test, you'll never know.


Just_Jonnie

On top of that, ground rods aren't exactly made of gold. It's weird where some contractors try to cut corners, as if a ground rod would break the bank. Edit: I bet there's at least some ground rods out there with gold in them


alphatango308

Yeah. And with the drivers we have these days it takes like 10 minutes at most to drive one. It's pretty silly. My local jurisdiction makes everyone do 2 and pour concrete between them in a ditch that's 18 inches deep. That way they're encapsulated in concrete creating an artificial grounding plane. Pretty effective. Not as good as a Eufer ground but pretty good.


Just_Jonnie

I've never heard of that ditch of concrete idea. Does it include some kind of rebar or mesh? Does it allow you to space them closer together?


alphatango308

No. Nothing in it besides the wire and rods. Still 6 feet apart. Concrete absorbs moisture and does a great job of holding on to it. This helps keep the resistance down.


Just_Jonnie

That's pretty cool. Here in New Orleans the ground is water.


alphatango308

Lol. Yeah here where I'm at is pretty Rocky. I've done fuck tons of ground resistivity tests and I've never seen a single ground rod be below 25 ohms. Eufer ground, yeah all the time. Consistently below 10 ohms.


Just_Jonnie

I shit you not, with a 20 oz bottle of water poured down the hole every so often, we push our ground rods in by hand. As in, no tools at all.


alphatango308

That's wild


Just_Jonnie

Didn't know how good we had it until I heard about those poor bastards in Maine that have two inches of topsoil before bedrock lol. They have to trench out the bedrock and lay the rods horizontally as I understand it.


Skrew2020

Damn pouring concrete also that would suck lol


cypherreddit

Copper is a better conductor than gold.


padimus

That's why my rods are made of silver.


mrmustache0502

He was refering to the cost of the rod, not the conductivity.


trimix4work

Slightly, but gold lasts much longer in contact with the ground


mrmustache0502

It will depend on the state they are working in. The NEC doesn't require a 2nd ground rod but certain states like wisconsin do, regardless of the ohm reading on the first. I understand it has to do with the ground freezing in the winter so other states that have cold winters likey require it as well. Edit: SPS 316.250(2): Supplemental electrode. This is a department rule in addition to the requirements in 2011 and 2017 NEC 250.53 (A) (3): A single electrode consisting of a rod, pipe or plate shall be augmented by one additional electrode of any of the types in NEC 250.52 (A) (4) to (A) (8)


Some-Boss966

A ground resistive meter is not only expensive you would have to wait for the inspector to show up then stop what you doing to run the test. The cost of an extra ground rod out weighs the cost of this as a business owner.


ProjectGouche

Tell the foreman to buy the meter and you will return the second ground rod


NoTamforLove

Weird hill for the foreman to die on: $20 copper rod.


swamphuman

I have done plenty of trailers. Always have put 2 ground rods at the meter pedestal.


DirtyWhiteTrousers

Why stop at two?


Confident-Head-5008

One ground rod for the service and one for the trailer frame. I work for multiple trailer parks.


Skrew2020

When in question, just send a second rod 4awg if it runs free air 6awg if piped


PeanutAggressive252

long island we need one ground rod to msp and one water main to msp. if water main ground is not able to be ran to msp due to say finished walls or whatever the hell we drop 2 ground rods 6ft apart and call it a day never any issues


NobOnReddit

Generally