ground rod pounder

[Bananaman321]

Whatever extra tools you need depends entirely on your soil type. I have pushed ground rods in for the first 5', and then wailed them in the last 3 feet with a sledge, and I've fought with them for an hour driving the thing at a 45 degree angle ( max allowed by code iirc). The rotary hammer attachments are great, either sds-max or spline drive, but you need a beefy rotary or demo hammer for it to do it. If you have rocky soil (NH ain't called the granite state for nothing), then expect to finish it with a sledge or a bandsaw (never do this, because code). I have a cheater for a sledge hammer so I can farmer that ground rod in. In sandy soils some people can pour water over the ground rod and push it in. You also, unless you have a ground resistance meter that can prove 1 has a resistance to ground of 25 ohms or less, have to drive 2.

I was required to get 12 Ohms. More than once I've had to drive over 50 feet into the ground and you could easily pour some water or pee on it and get that but that's cheating and if someone happened to check your work on a dry day? That's why I drove a minimum 20 feet.

I pulled old power pulls out of the ground during a utility re-conductor that just had the ground wire coiled about six times on the bottom of the pole and stapled to it. I assume that must have been the build code back 40-50 years ago.

 

[going_commando]

I was required to get 12 Ohms. More than once I've had to drive over 50 feet into the ground and you could easily pour some water or pee on it and get that but that's cheating and if someone happened to check your work on a dry day? That's why I drove a minimum 20 feet.

I pulled old power pulls out of the ground during a utility re-conductor that just had the ground wire coiled about six times on the bottom of the pole and stapled to it. I assume that must have been the build code back 40-50 years ago.

You can't get that low in NH. We have an open pit mine that we take care of, and have to do a ground grid test annually per MSHA (mining version of OSHA). There are a pile of ground rods and hundreds of feet of #4 copper in the ground, and if you are more than 25' away it's at least 100 ohms. We have an earth ground resistance meter, and it reinforces the futility of ground rods here. Difference in potential is a real hazard that I understand, and do what I can to mitigate, because playing with higher voltages (400+) is dangerous, and the last thing you want to have is someone grabbing on to something steel when a motor or whatever is faulted and getting belted and/or killed. If anything, PV circuits not being grounded is safer, since the risk of being part of the circuit is substantially lower.

The next best thing is what the code requires, which is to eliminate the difference in potential as much as practically possible by driving ground rods and bonding them to the equipment grounding conductor, and bonding the chassis of the solar panels. I don't want to belittle the importance of this in any way. The last thing you want to happen is for someone to get belted because a solar panel fails, grounds out, and none of the protective devices pick it up, and they get killed.

 

[Bananaman321]

You can't get that low in NH. We have an open pit mine that we take care of, and have to do a ground grid test annually per MSHA (mining version of OSHA). There are a pile of ground rods and hundreds of feet of #4 copper in the ground, and if you are more than 25' away it's at least 100 ohms. We have an earth ground resistance meter, and it reinforces the futility of ground rods here. Difference in potential is a real hazard that I understand, and do what I can to mitigate, because playing with higher voltages (400+) is dangerous, and the last thing you want to have is someone grabbing on to something steel when a motor or whatever is faulted and getting belted and/or killed. If anything, PV circuits not being grounded is safer, since the risk of being part of the circuit is substantially lower.

The next best thing is what the code requires, which is to eliminate the difference in potential as much as practically possible by driving ground rods and bonding them to the equipment grounding conductor, and bonding the chassis of the solar panels. I don't want to belittle the importance of this in any way. The last thing you want to happen is for someone to get belted because a solar panel fails, grounds out, and none of the protective devices pick it up, and they get killed.

This is straight from my lineman's and cableman's handbook

If when the rod is driven to its full length it is found that the resistance is not well below 25 Ohms, resort can be had to one of the two following prosedures:
1. Extend the length of the rod.
2. Drive additional rods.

Option one is the only one excepted in the contracted build code at that time.