Advice Wanted - VERY High Earth Resistance Problem

[Axnfell]

I have been doing some tests around our property here and I cannot get the earth resistance test to get anywhere lower than 1.86k, even started tested now up to 30 meters away from the property and still cannot get any lower readings.

Any advice would be greatful.

Kind Regards

James

 

[davesparks]

Earth Rods are being hit in to their entire length, approx 1m deep, cannot get much deeper as we are hitting bedrook, have tested using |KEW-5105A and then tried removing the earth rood and testing again 1 meter further away from the property and so on, but cannot get the reading to get any lower. The soil is not the best, looks as though its had about 100 years of tiles, bricks and plaster pored into it.

1m is not deep enough to get an Ra which is stable long-term.
And using just one rod is not a very good plan either.
You need to go deeper or else find another method of installing an earth electrode

 

[Yozza19]

900x900 earth mat on bed of marconite about 3 m deep

 

[Axnfell]

They kind of live in the middle of woodland, on a hill that seems to be basically baserock with a light covering off soil and roots, all looks lovely but a real pain at the moment, I have not tried Tape yet, I was kind of hoping that this would be a simple fix somewhere along the line, Will have to pop to Yesss on Monday to see if they have any tape in stock, Thanks guys for the help, Very much appreciated.

 

[jamie-spark]

Do you have access to another test instrument to make sure your meter/ leads are not faulty.

If the ground is hard you need an sds max gun with an attachment to make easy work of it, I’ve done an install at Loch Lomond where the ground was full of rocks, it can make a lot of difference if you sharpen the end of the first rod to a point as this can break small rocks or help deflect the electrode when going down. As others have said you’ll need more than just one electrode for stability , I usually go for a minimum of 3 1.2 m you may also need multiple electrode sites. The above job I mentioned we hade 5 electrode pits with 4 electrodes deep as the soil resitivity was poor although we were looking to achieve an Ra of under 10 ohms

 

[westward10]

Stick the rod into a tree.

 

[UKMeterman]

Hi,
This link might give some ideas. https://www.wbdg.org/FFC/NAVFAC/DMMHNAV/hdbk419a_vol1.pdf

 

[mhar]

Hi,
This link might give some ideas. https://www.wbdg.org/FFC/NAVFAC/DMMHNAV/hdbk419a_vol1.pdf

Got to page 403 then gave up

 

[johnduffell]

I’d look at burying tape rather than rods and create an Earth nest.

I got a c asking Ra last week even with all the sun we’ve had.

0.74ohms can't be going through the earth surely, did you touch the water supply pipe on the way down and are going back to the network via someone else's bonding?

 

[Strima]

0.74ohms can't be going through the earth surely, did you touch the water supply pipe on the way down and are going back to the network via someone else's bonding?

I didn't install it, only tested it, it's been in the ground 15 years.

I reckon it's hit another service on its way down, according to the paperwork the rod is 5/8" and 3m long so not a twig by any means.

 

[davesparks]

0.74ohms can't be going through the earth surely, did you touch the water supply pipe on the way down and are going back to the network via someone else's bonding?

Why can’t that be going through the earth? The DNOs regularly achieve Ra lower than that for substations

 

[johnduffell]

Why can’t that be going through the earth? The DNOs regularly achieve Ra lower than that for substations

I assumed he wasn't t testing a substation just a normal rod, but i did add a "surely", to account for the fact that it could be some crazy setup for amateur radio or something

 

[Gavin John Hyde]

Need to borrow neighbours dogs and encourage them to cock there legs on the top of the rod! will help get a better reading, failing that a bit of marconite could do the trick.

 

[static zap]

Got to page 403 then gave up

Fore warned ..403 Went straight to appendix-es ..
Now getting bored with list .

EARTH ELECTRODE SUBSYSTEMS -- 11, 24, 25, 31, 33, 44, 51, 52, 63, 64, 65, 66, 70, 7 1 , 85, 86, 87, 8 9 , 101,
107, 120, 131, 137, 138, 145, 148, 170, 187, 190, 196, 205, 212, 213.

213 ..FAIL ..mostly surface corrosion /good connection (+ RF Impedance)

.... Then got side tracked with memories "Things wrapped in Brown wax paper ,in heat sealed polythene bags..."
( may see if my -Inner lucky stumble , is working later )

 

[Axnfell]

Managed to get it down to 112 Ohms, after paying out a small fortune, 3 earth rods later all connected with flat copper tape (25mm x 3mm x 25m) dug into the ground about 12” deep, couldn’t get any deeper due to roots and rock. Thanks guys for the advice

 

[Strima]

Managed to get it down to 112 Ohms, after paying out a small fortune, 3 earth rods later all connected with flat copper tape (25mm x 3mm x 25m) dug into the ground about 12” deep, couldn’t get any deeper due to roots and rock. Thanks guys for the advice

Cool, go back when you've had a couple of days rain and test again, just out of curiosity.

Personally I wouldn't have bothered with rods and gone solely for tape.