Todays Earth Rod Efforts

[uksparks]

Hi,

As I mentioned last night, I was going to be putting the earth rods in for this summer house this morning.

I put 8 rods in, this was one stack of two, and two stacks of three rods.

The readings from the two that were 3 rods deep were around 10 Ohms per location, and the two rod stack was approx 17 Ohms.

I tested the first rod at approx 10 Ohms, then connected the second rod to the first which was 17 Ohms which them reduced the total down to approx 6 Ohms, then connected the third rod which was 3 deep and that bought it down to 3.2 Ohms.

So the Ra that I achieved today was a respectable 3.2 Ohms

All rods were connected together with 16mm earth.

I am going to go back next week and bang in another couple of piles of two rods so another four in total because I want to get that sub 1 Ohm reading.

Anyway, what do you think, 3.2 is not bad is it!!


Reading from first rod: 10.6 Ohms (3x 4ft 5/8" Rods)


Reading from second rod: 17.2 Ohms (2x 4ft 5/8" Rods)


Reading from third rod: 9.6 Ohms (3x 4ft 5/8" Rods)


Reading from first and second rod combined: 6.3 Ohms


Reading from all three rods connected together: 3.2 Ohms

 

[NDG Elecs]

Hi,

As I mentioned last night, I was going to be putting the earth rods in for this summer house this morning.

I put 8 rods in, this was one stack of two, and two stacks of three rods.

The readings from the two that were 3 rods deep were around 10 Ohms per location, and the two rod stack was approx 17 Ohms.

I tested the first rod at approx 10 Ohms, then connected the second rod to the first which was 17 Ohms which them reduced the total down to approx 6 Ohms, then connected the third rod which was 3 deep and that bought it down to 3.2 Ohms.

So the Ra that I achieved today was a respectable 3.2 Ohms

All rods were connected together with 16mm earth.

I am going to go back next week and bang in another couple of piles of two rods so another four in total because I want to get that sub 1 Ohm reading.

Anyway, what do you think, 3.2 is not bad is it!!


Reading from first rod: 10.6 Ohms (3x 4ft 5/8" Rods)
View attachment 29132

Reading from second rod: 17.2 Ohms (2x 4ft 5/8" Rods)
View attachment 29134

Reading from third rod: 9.6 Ohms (3x 4ft 5/8" Rods)
View attachment 29133

Reading from first and second rod combined: 6.3 Ohms
View attachment 29135

Reading from all three rods connected together: 3.2 Ohms
View attachment 29131

Good work. Bet you only get down to 1.5 ohms with the next rods driven in mate....sods law I think we call it! You could always put any RFCs on a 20A and tell them they can't use their electric shower and hob!! Tell them disconnection times are very very important!! Look forward to the update mate.

Neil

 

[mechelec]

3.2ohms is not bad it will be better when you get it finished ; )

 

[Richard Burns]

No a load of rubbish, pull them all out and start again!!:mad2::53:

I would say 3.2Ω is a pretty good reading, 71A fault current enough to trip a 10A MCB.
Pretty close to the resistors in parallel results actually which is interesting to know.
Thanks for putting in the effort to give us some feedback.

 

[uksparks]

I think I'll put two more locations in and end it there, I bet each will knock an ohm off the figure.

it about killed me off beating them in with a lump hammer!

By the time the group has settled the reading will have got better as its really only the bottom rods that are in are touching the earth as the others are flapping round due to the couplers.

 

[Richard Burns]

Manually driven gives you some definite points, I am just not sure if they are for stupendous effort or stubborness!

 

[NDG Elecs]

Manually driven gives you some definite points

I think the points are called callouses aren't they!

 

[uksparks]

The first one was easy, the second was a little touch, but the third rod was the killer, the deeper you go, it just gets sodding hard work.

I need to achieve a higher fault current really as 71A is pants, just looking at the time current tables in the BYB and max zs etc.

 

[Andy78]

I applaud your efforts with this one I really do. Looks like you will end up with something close to very good.

I have to say though, driving coupled rods with a lump hammer..... don't you like yourself very much ?

 

[Marvo]

I think I'll put two more locations in and end it there, I bet each will knock an ohm off the figure.

it about killed me off beating them in with a lump hammer!....

You must be mad, get an attachment for a jackhammer. Also if you want a better Ra go 1 rod deeper on all your existing locations rather than making new locations.

By the time the group has settled the reading will have got better as its really only the bottom rods that are in are touching the earth as the others are flapping round due to the couplers.[/QUOTE]

 

[uksparks]

Im not going to get a 0.2s disconnection with 71A, so need to improve that some what!

How many amps am i going to need to get 0.2s ? I know its RCD protected but thats not the point!

 

[uksparks]

You must be mad, get an attachment for a jackhammer. Also if you want a better Ra go 1 rod deeper on all your existing locations rather than making new locations.

By the time the group has settled the reading will have got better as its really only the bottom rods that are in are touching the earth as the others are flapping round due to the couplers.

[/QUOTE]

I could try putting another on the top of them, I could do with someone holding the rod so i can hold the hammer with two hands.

 

[Corbs]

I could try putting another on the top of them, I could do with someone holding the rod so i can hold the hammer with two hands.[/QUOTE]

or one of these much easier

[video=youtube;vvCZvNj8H30]https://www.youtube.com/watch?v=vvCZvNj8H30[/video]

 

[Marvo]

If you really want to be a diehard, instead of using a sledge hammer use a slide hammer. See this thread.

 

[uksparks]

I might need to get myself one of them! it took me two hours of hard graft getting those rods in!

 

[uksparks]

I'd need an SDS max bit wouldn't I? and I could rent a drill to do it, presumably an SDS max drill would do it or would I need something bigger?

 

[Corbs]

I could try putting another on the top of them, I could do with someone holding the rod so i can hold the hammer with two hands.[/QUOTE]


you tried something like this? might help

[video=youtube;0sLv4LLVPbA]https://www.youtube.com/watch?v=0sLv4LLVPbA[/video]

 

[Corbs]

I'd need an SDS max bit wouldn't I? and I could rent a drill to do it, presumably an SDS max drill would do it or would I need something bigger?

thats fine, prob normal sds would do but might take longer, but vid below is sds max demolition hammer

[video=youtube;VJYhHZYu_4g]https://www.youtube.com/watch?v=VJYhHZYu_4g[/video]

 

[uksparks]

Thats not a bad idea.

 

[telectrix]

i just get glennsparks to come round and snarl at the rod. the rod then drives itself in.:uhoh2: