Corroded Ground Rod Indoors

[xguard]

It's indoors in an electrical closet. I think bleach or other cleaning products were stored in the room at one point. Was planning to replace the wire and clamp, possibly the rod also. Looking for input.

1. Good idea to replace rod?

2. Is there a good way to test ground rods that are installed indoors? Where you don't have easy access to the earth for the fall off potential method? (Installing a second rod 6' away would put it in another room or other inconvenient location.)

Thanks

 

[zbang]

I'd just clean the rod and replace the clamp, once you strip back the wire, it's probably fine.

While I wouldn't say never, the likelihood of pulling that rod without a major fight is quite low.

 

[Rick 0920]

After wire brushing and clamp replacement, coat the exposed part of the rod and conductor with an oxide inhibitor (noal-ox, penetrox) That will help for future oxidation.

 

[petersonra]

WHAT DIFFERENCE WOULD IT MAKE.

Incidentally, why is there only one rod? If you are going to "fix" it, install the required second rod.

 

[LarryFine]

The oxidation is only superficial.

 

[tom baker]

And if that’s an 8ft rod, it does not meet code requirement to be driven 8 ft deep

 

[4x4dually]

And if that’s an 8ft rod, it does not meet code requirement to be driven 8 ft deep

Dang 7'10-3/4 !!! LOL

 

[tom baker]

WHAT DIFFERENCE WOULD IT MAKE.

Incidentally, why is there only one rod? If you are going to "fix" it, install the required second rod.

2nd rod is not always required, but is best option over testing resistance

 

[tom baker]

In

Dang 7'10-3/4 !!! LOL

In using units, since is a 8ft rod, the accuracy is + or - .5 ft. If the code said 8.0 ft the the accuracy is 0.5
So 7 - 10 3/4 is ok, but tell that to an inspector, LOL indeed.

 

[petersonra]

In

In using units, since is a 8ft rod, the accuracy is + or - .5 ft. If the code said 8.0 ft the the accuracy is 0.5
So 7 - 10 3/4 is ok, but tell that to an inspector, LOL indeed.

Where does it say that in the code?

 

[norcal]

If that rod was done prior to the adoption of the edition of the NEC that required either proving 25 Ohms of resistance or less, or driving a 2nd rod, it is just fine.

 

[AC\DC]

It’s a 10 foot rods what are you talking about!

 

[tom baker]

Where does it say that in the code?

It doesn’t but is the accepted method, it’s one half of the least significant figure. Look in Wikipedia. Like I said, LOL

 

[petersonra]

It doesn’t but is the accepted method, it’s one half of the least significant figure. Look in Wikipedia. Like I said, LOL

wikipedia is not part of the code.

 

[tom baker]

wikipedia is not part of the code.

Yes, but it explains the principle behind measurements. Your measurements can be no more precise than the least accurate measurement. Or say you a measuring tape that is only market in feet. Your accuracy is .5 ft

 

[petersonra]

the code says you have to support a conduit every ten feet. so if you do it every 10.5 feet you are OK?

 

[garbo]

It's indoors in an electrical closet. I think bleach or other cleaning products were stored in the room at one point. Was planning to replace the wire and clamp, possibly the rod also. Looking for input.

1. Good idea to replace rod?

2. Is there a good way to test ground rods that are installed indoors? Where you don't have easy access to the earth for the fall off potential method? (Installing a second rod 6' away would put it in another room or other inconvenient location.)

Thanks


View attachment 2559107

Did a lot if work in machine shops where back in the 1980' s service techs installing CNC machines demanded a ground rod at each machine. One shop moved maybe 7 or 8 years and made a heavy steel clamp to pull out halve a dozen ground riids against my wishes. All were several corroded to where diameter was less then halve if the original 5/8" diameter. I refused to install ground rods and had the backing of my inspector. Told the CNC tech guys to make a copy of where the ground rod is required for every CNC machine in the NEC. Gave me the run around and said they would not provide warranty service. They finally said that ground rods were not needed after machine shop lawyer sent them a certified letter on this matter.

 

[darekelec]

one time I installed a ground rod as an update and then saw 2 rmc 4" service conduits in the ground. was my rod any important? nope