diy solar

diy solar

Ground rod?

Guda

Guda

Superstrut Strut
Joined
Nov 19, 2019
Messages
516
My ground is crazy tough to dig deep. I am pretty sure there would be no way to pound in 8' of copper. Even with all the ways I have looked up. Can I just dig a hole with my backhoe & then put in the ground rod.

Will back filling a hole be the same as pounding in the rod?
Is getting it close to the equipment the only consideration?
 
It boils down to the resistance (impedance). You can't just whack a rod in and say done. Check your local electrical standard. Somewhere in its many pages it will tell you what that measurement must be (or be better than). It might even detail the process for determining what the impedance of your installation is.
 
gnubie said:
It boils down to the resistance (impedance). You can't just whack a rod in and say done. Check your local electrical standard. Somewhere in its many pages it will tell you what that measurement must be (or be better than). It might even detail the process for determining what the impedance of your installation is.
Click to expand...
Not ignoring the important content above - What about a 60# electric jackhammer and a rod driver? Any good tool rental business will have this combination of tool and accessory.
 
If its really that hard to dig, maybe your local code allows for different things than the national standard.
 
mapguy525 said:
What about a 60# electric jackhammer and a rod driver? Any good tool rental business will have this combination of tool and accessory.
Click to expand...
Aaron_85 said:
Do you have a hammer drill?
something like this works wonders. this one is for an SDS drill, but ones exist that just go into a regular chuck too
Click to expand...
I did see this method & I do have a SDS, on the small side.
smoothJoey said:
If its really that hard to dig, maybe your local code allows for different things than the national standard.
Click to expand...
It is pretty tough. Very interesting geology. About 2' of topsoil & then a layer of various size/kind of hard packed rock. Below that is, I don't know what its called. Its like packed dirt. Bubbles when submerged. Hard but will crumble. I've dug it all with the backhoe & can dig a hole deep enough to put the rod in. I'll try to find the local code.
 
Try to drive the rod after a few days of heavy rain. Here in south Texas the dry clay is like rock, but when wet is easy to dig. This is the only way I could dig fence posts.
 
I have driven in many grounding rods over my lifetime, rarely has it been that hard to do, just be patient and watch out for your legs when swinging the sledge. One miss can be REALLY painful.

Alternately, you CAN use a Grounding Plate such as this below:
These can be installed 30 inches below surface and 24" from the building itself. These provide the same amount of "contact surface" as a 6' long rod but are more suitable in rocky soils and where a rod cannot be necessarily installed. I used these on my current home as I have rocky soils and it was far more practical & easier to do.
!*! Always check with your local Electrical Code requirements, they will ALL address proper grounding techniques for your region and such things should always be done to comply with codes.

 
gnubie said:
It boils down to the resistance (impedance). You can't just whack a rod in and say done.
Click to expand...
Very good point.

For general info, I had to replace* a ground rod for a house because the earth loop impedance was too high. The rod was in as far as code required but still didn't have a low enough impedance**. I forget the exact number but it was in hundreds of ohms, this is a problem because anything over 100's of ohms does not a decisive fault current make, hence MCBs wouldn't trip effectively (I = V / R). You can all test this yourself with devices such as this:

2020-01-30_13-59-51.png


*when I say replace, I mean I had to have another fitted in a different location.
**I'm guessing it was raining super-conducting rain when the electrician certified the installation, or probably more likely, he didn't test it.
 
tictag said:
Very good point.

For general info, I had to replace* a ground rod for a house because the earth loop impedance was too high. The rod was in as far as code required but still didn't have a low enough impedance**. I forget the exact number but it was in hundreds of ohms, this is a problem because anything over 100's of ohms does not a decisive fault current make, hence MCBs wouldn't trip effectively (I = V / R). You can all test this yourself with devices such as this:

View attachment 15442


*when I say replace, I mean I had to have another fitted in a different location.
**I'm guessing it was raining super-conducting rain when the electrician certified the installation, or probably more likely, he didn't test it.
Click to expand...

How does that work?
It looks like the UK equivalent of a North American outlet tester.
I don't think ours can test the impedance of the "dirt circuit", because the neutral ground bond facilitates a much lower impedance path back to the transformer.
Dirt circuit... I just made that up, hope it sticks.
 
It might have a flying probe on a long lead that is not shown. Plug unit into GPO, stick probe into ground at appropriate distances from the earth rod.

The UK has different earthing systems in use too. It's possible that the earth comes in from the electricity network rather than a local earth rod / plumbing earth so it's testing the overall neutral earth loop.
 
gnubie said:
It might have a flying probe on a long lead that is not shown. Plug unit into GPO, stick probe into ground at appropriate distances from the earth rod.

The UK has different earthing systems in use too. It's possible that the earth comes in from the electricity network rather than a local earth rod / plumbing earth so it's testing the overall neutral earth loop.
Click to expand...

I just found this https://martindale-electric.co.uk/product/ez165-socket-non-trip-earth-loop-tester/
Nice tester.
This video show how uk wiring is donehttps://youtu.be/W0_1xRqT8uU?t=142
Based on that I suspect this device is testing the fault current path impedance back through the neutral as opposed to the "dirt circuit".
 
smoothJoey said:
How does that work?
Click to expand...
I don't know the circuitry behind the tester, but the product page and datasheet is here and here. I do know that it is specifically designed to test earth loop impedance, just without the hundreds of pounds price tag for professional products. I use it to test caravan site EHU supplies beford I plug my caravan into them.
 
gnubie said:
It's possible that the earth comes in from the electricity network rather than a local each rod / plumbing earth so it's testing the overall neutral earth loop.
Click to expand...
This is definitely the usual case here in the UK (i.e. TN-S-C) but this house was whatever 'no utility earth' system is, hence the earth rod. After the new earth rod was fitted, the tester showed 'green' (I forget the value).
 
smoothJoey said:
Based on that I suspect this device is testing the fault current path impedance back through the neutral as opposed to the "dirt circuit".
Click to expand...
If it was just measuring impedance to the neutral line, it wouldn't show me a different value for one ground rod over another. I don't know for sure, I just called an electrician to 'fix it'.

p.s. Maybe he just cleaned up the ground terminal lug and charged me a day's labour for the help!! ?

Edit: Added postscript.
 
Just started whacking at that ground rod I bought. Got over 1/2 way before I needed a extended break from whacking. I tried looking up code. Turns out I am not a code reader. I live in a area where you can code or not. Not coding currently. Just going to solid, quality & future proof.
 
Guda said:
Just started whacking at that ground rod I bought. Got over 1/2 way before I needed a extended break from whacking. I tried looking up code. Turns out I am not a code reader. I live in a area where you can code or not. Not coding currently. Just going to solid, quality & future proof.
Click to expand...

If you are not going to code is their something metallic in the ground already that you can bond to.
Like a well casing or similar?
Anybody know of a reason not to do that?
 
evad said:
You can add a second rod in parallel. Some localities require two.
Click to expand...
I was watching a video of a guy installing a breaker panel & he referenced having 2.
smoothJoey said:
If you are not going to code is their something metallic in the ground already that you can bond to.
Like a well casing or similar?
Click to expand...
Don't have anything like that. I'm sure I'll be fine after a few more whack sessions.
 
I saw a video by Wild Wonderful Off Grid on YT where the owner (a licensed electrician in the US) laid two ground rods horizontally in a trench. Can't put my finger on it right offhand but he mentioned that it complied with NEC requirements.

And from my limited experience, it seems like local/regional code jurisdictions are simply adopting national codes in order to keep things simpler and more consistent. Now I'm sure this isn't the case everywhere but seems like complying with a national code is probably gonna work for most situations.
 
tictag said:
This is definitely the usual case here in the UK (i.e. TN-S-C) but this house was whatever 'no utility earth' system is, hence the earth rod. After the new earth rod was fitted, the tester showed 'green' (I forget the value).
Click to expand...
Came across this youtube clip which people may find useful in understanding the earthing systems in use in the UK

 
You must log in or register to reply here.

Similar threads

e67
another grounding issue
Replies
2
Views
167
e67
e67
N
Yes, another “grounding” question, lol
Replies
1
Views
267
JBoffgrid2022
JBoffgrid2022
iowachap
Eg6000 xp earth ground
Replies
1
Views
300
FilterGuy
FilterGuy
Bluedog225
Can I run a ground through the slab?
Replies
3
Views
335
Bluedog225
Bluedog225
M
Eg4 6000xp off grid
Replies
2
Views
333
TexanSun
T

diy solar

diy solar
Back
Top