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

 

[telectrix]

pleas explain what you're trying to do. are you looking to get a Ra?

 

[Axnfell]

Hi, Yes trying to test 'Ra', Here on the Isle of Man most of the Island is TT based Earthing.

 

[telectrix]

are you banging in a decent sized rod?

 

[SJD]

How exactly are you testing, and what depth of earth rod?

Round here I can almost get a few kOhm by just dipping the end of my test probe in the soil!

 

[Axnfell]

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.

 

[Octopus]

Try watering the ground

 

[telectrix]

hire one of these beasties. maybe HSS do them:

 

[Strima]

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.

 

[telectrix]

1553 and Wiha screwdrivers.... copycat. .

 

[Strima]

1553 and Wiha screwdrivers.... copycat. .

1552, I’m not as much of a tool tart as you...

 

[telectrix]

1552 and 1553 best MFTs ever. just had mine calibrated for 4th time since buying 2nd hand from MDJ, 5 years ago.

all the 1553 has over the 152 is bluetoth which i never use.

1. i don't need it.
2.i don't undersatand it anyway.

 

[Strima]

Had to get mine repaired, the test lead sockets fell to bits, apart from that I’ve never had a problem with it.

 

[SJD]

A depth of 1m is not that deep, I normally drill the first 1m with an extra long bit first. But if it really is solid rock after 1m then I appreciate going deeper could be tricky, unless you can find some super-long drill bits. Possibly burying tape, or an array of rods spaced out might be worth trying.

What about neighbours, assuming there are any, what sort of values do they have?

 

[telectrix]

Had to get mine repaired, the test lead sockets fell to bits, apart from that I’ve never had a problem with it.

could have done that yoursen.

 

[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.