How we Earth here

[malcolmsanford]

Just thought I would start some posts for some of the less experienced lads on here, and for guys who are predominately domestic.

Here is the start of what is going to be a 3 story building. Grd floor workshops and tech area 1st floor will be classrooms and briefing areas and offices final floor offices, conference room, etc




Because of the system here we do get our protective earth from the supply transfomer which is going to be installed during this build. Which was sized as 700KVA



Above though is going to be part of the earthing system as well, but will be more functional earthing. This will be tied in with earth pits and will form a 1ohm requirement for IT. This is the famous ufer earthing system which I think as been covered on here and will when tied in with the pits will give me less than the required 1 ohm



This is the result. I have 4 x 95mm conductors on each of the 4 corners of the building and we start from there

If people are interested I'll post over the coming months, the TX installation, to the building being built and various stages of the installation till completion .

This though is just 1 of 6 new builds I have and 14 refurbs lol

 

[Hellmooth]

Would love to see any pics of the installs, very interesting! Where about are you?

 

[malcolmsanford]

Yes I'll post when things are starting to take off. If anyone of the lads want to ask anything I'll try and answer as best I can.

I'm in Saudi, we are upgrading ....a military facility can't really say much more lol

 

[Leesparkykent]

How much will it cost to achieve the <1Ohm figure? Should make an interesting thread

 

[malcolmsanford]

I normally try and drive a rod in every 7-9mtrs around the Building. I use 1800mm x 19mm rods so I'm guessing with the buildings foot print we will have about 17-18 rods in total. All the rods will be linked with a 70mm bare conductor laid in earth.

Theses will also tie in with the lightning system so I will be looking at a result of 0.5 ohms or less to be honest Lee.

I have stopped us using Furse, no reflection on furse, it is good stuff, but compared to Wallis it's twice the price and that is bringing Wallis from the UK

In the scheme of things I'm guessing the system will be 3-4K UK

 

[Deleted member 72666]

Would love to see any pics of the installs, very interesting! Where about are you?

+1....

 

[UNG]

I normally try and drive a rod in every 7-9mtrs around the Building. I use 1800mm x 19mm rods so I'm guessing with the buildings foot print we will have about 17-18 rods in total. All the rods will be linked with a 70mm bare conductor laid in earth.

Theses will also tie in with the lightning system so I will be looking at a result of 0.5 ohms or less to be honest Lee.

I have stopped us using Furse, no reflection on furse, it is good stuff, but compared to Wallis it's twice the price and that is bringing Wallis from the UK

In the scheme of things I'm guessing the system will be 3-4K UK

Other than the price of their kit, used Wallis stuff for many years because Furse seem to charge for their name when buying their kit

 

[snowhead]

....a military facility can't really say much more lol

If we don't hear from you again we'll know you've already said too much, you'll be kissing the Ufer under the concrete..

 

[GMES]

The Attached Pdf is Malcoms donation to the thread, but he was having issues with the system so thank him not me for this please guys.

 

[Robson689]

I normally try and drive a rod in every 7-9mtrs around the Building. I use 1800mm x 19mm rods so I'm guessing with the buildings foot print we will have about 17-18 rods in total. All the rods will be linked with a 70mm bare conductor laid in earth.

Theses will also tie in with the lightning system so I will be looking at a result of 0.5 ohms or less to be honest Lee.

I have stopped us using Furse, no reflection on furse, it is good stuff, but compared to Wallis it's twice the price and that is bringing Wallis from the UK

In the scheme of things I'm guessing the system will be 3-4K UK

What sort of readings are you getting from the rebar once the concrete has been poured?

I always find it to be hit and miss a job I did recently was getting readings of under 0.10 ohms but on another job similar sized concrete slab was over 700 ohms. Probably just down to the quality of the rebar ties or something I'd imagine but curious nonetheless.

 

[malcolmsanford]

What sort of readings are you getting from the rebar once the concrete has been poured?

I always find it to be hit and miss a job I did recently was getting readings of under 0.10 ohms but on another job similar sized concrete slab was over 700 ohms. Probably just down to the quality of the rebar ties or something I'd imagine but curious nonetheless.

You would probably find rather than the steel ree bar being the culprit, that it is the concrete itself that is giving you the poor results.

I've seen literally a piece of ree bar pushed in a concrete pour and once it formed that was used as the earth rod and results were pretty good, I can't remeber the exact results but it was less than 10 ohms

Your 700 ohms is surprising though.

 

[malcolmsanford]

The Attached Pdf is Malcoms donation to the thread, but he was having issues with the system so thank him not me for this please guys.

Thanks Glen.

I posted this mainly for the trainees and perhaps guys that are just getting into design. It's a doc I developed out here that we submit to the clients O+M office for approval.

You can see, hopefully how we go about doing the intial design and I'm sure it can be altered, or changed to suit. Notice I haven't put R1 + R2 on it, here that would totally confuse things lol. Back in the UK youd could add a column for that

Just hope it might help someone