Earth rod installation

Lwols · Mar 19, 2019

Hi all,

I'm having a car charger fitted in the next 2 weeks and the installer has mentioned they shall be fitting an earth rod.

I'm not too concerned as I'm sure these guys know what they are doing! However, I wondered how they will drive a rod into the ground whilst avoiding utilities, etc.

Also, the rod looks like it's going in near a gravel patch, so how would other professionals install a rod, would you drill a hole into the ground then hammer it or is there a tool needed to drill a rod into the ground.

Thanks!

Nigel · Mar 19, 2019

You can drive it in with a drill but this is not best practice in-line with H&S legislation.

We hand dig with GRP fence post spades and CAT scan every 300mm.

Increasingly we are installing earth mats but these require a little more skill and expense to work with. The advantages is only need to dig to 350mm. The disadvantages is need to dig a square 1000x1000 and cost more.

Robson689 · Mar 19, 2019

Personally CAT scan around the area usually 1m² where the rod is going and put first 1.2m rod in with sledgehammer then the others on top with Hilti te1000 with earth rod attachment

Top Cat · Mar 19, 2019

Looks like i am going to be busy with all these CAT scans.

KEV 1 N · Mar 19, 2019

Top Cat said:
Looks like i am going to be busy with all these CAT scans.

A doctor tried to replace his living room light, but kept blowing the fuse. He called an electrician, The electrician arrived, unpacked his tools, looked at the light and said “Ah! The old all the reds and blacks together ploy!” He sorted the wiring and handed the doctor a bill for £500.
The doctor exclaimed, "This is ridiculous! I don't even make that much as a doctor!."
The electrician quietly answered, "Neither did I when I was a doctor."

[ElectriciansForums.net] Earth rod installation

Lwols · Mar 19, 2019

Robson689 said:
Personally CAT scan around the area usually 1m² where the rod is going and put first 1.2m rod in with sledgehammer then the others on top with Hilti te1000 with earth rod attachment

That's interesting. Thanks for that

If the earth is hard and dry would you tend to water it and knock in? Or would you go straight to knocking it in with the SDS / Hilti?

Also, isn't this bloody dangerous! It seems to me it's required due to the risk of losing the incoming Neutral but I've never heard of an example of this happening in the UK?

What if you have a bloody block paving drove etc.!

buzzlightyear · Mar 19, 2019

Earth rod only if tncs exporting a earth from Dnohttps://www.google.com/url?sa=t&source=web&...FjAAegQIARAB&usg=AOvVaw221IQqjRFazFVzav3AO9es

Lwols · Mar 20, 2019

buzzlightyear said:
Earth rod only if tncs exporting a earth from Dnohttps://www.google.com/url?sa=t&source=web&rct=j&url=https://www.voltimum.co.uk/articles/installation-electric-vehicle-charging&ved=2ahUKEwjalKK-rI_hAhVYXRUIHS3hD7IQFjAAegQIARAB&usg=AOvVaw221IQqjRFazFVzav3AO9es

Thanks for that. Really interesting.

Isn't it more often than not a TNCS?

Very rarely a TT and same for TNS?

I just can't get my head around the risk with driving rods into the ground and not knowing for sure where any itilieuti are lay!

StephenRowley · Mar 20, 2019

I'm just a wee apprentice but isn't the need for a rod with a charge becuase they don't want DC fault currents flowing though the ac earthing system?

DPG · Mar 20, 2019

Lwols said:
It seems to me it's required due to the risk of losing the incoming Neutral but I've never heard of an example of this happening in the UK?

What if you have a bloody block paving drove etc.!

This does happen, especially in the joint boxes under pavements which tap off and feed each house on the street.

Block paving is neither here nor there -if a rod is needed then a rod is needed. Block paving would need to come up.

davesparks · Mar 20, 2019

Lwols said:
Also, isn't this bloody dangerous! It seems to me it's required due to the risk of losing the incoming Neutral but I've never heard of an example of this happening in the UK?

What if you have a bloody block paving drove etc.!

To hear about it happening you would have to be listening in the right places, it's not something the media is ever going to care about or publicise.
I'm sure there are many people on this forum who have heard of it or experienced it.

If you have bloody block paving then you should clean the blood off of it, and probably be a bit more careful not to spill blood on it in the future.

Midwest · Mar 20, 2019

davesparks said:
If you have bloody block paving then you should clean the blood off of it, and probably be a bit more careful not to spill blood on it in the future.

Thats nearly as bad at Pete's attempts at humour

mattg4321 · Mar 20, 2019

essex said:
You can drive it in with a drill but this is not best practice in-line with H&S legislation.

We hand dig with GRP fence post spades and CAT scan every 300mm.

Increasingly we are installing earth mats but these require a little more skill and expense to work with. The advantages is only need to dig to 350mm. The disadvantages is need to dig a square 1000x1000 and cost more.

I can imagine the number of earth mats installed for a domestic EV charger is probably zero!

Out of the many I've seen installed, most haven't even banged a rod in!

Midwest · Mar 20, 2019

Lwols said:
It seems to me it's required due to the risk of losing the incoming Neutral but I've never heard of an example of this happening in the UK?

The latest amendment to the wiring regs apparently (I've not done the 18th), precluded the use of a PME supply or its earthing system for car chargers (less you can achieve certain conditions). So if you have a TN-C-S it has to have a separate earth via a earth rod, unless your vehicle is being charged within the confines of the property, not on the drive for example.
Seems your electrician might be offering good advice?

Lwols · Mar 20, 2019

Midwest said:
The latest amendment to the wiring regs apparently (I've not done the 18th), precluded the use of a PME supply or its earthing system for car chargers (less you can achieve certain conditions). So if you have a TN-C-S it has to have a separate earth via a earth rod, unless your vehicle is being charged within the confines of the property, not on the drive for example.
Seems your electrician might be offering good advice?

Needless to say, I agree.

He seems like a very decent bloke.
Should I be expecting the earthing cable to be running in conduit up and into the charger.

Does it matter about the size of earthing, assuming 10mm will be ok? Or do the regs mention 16mm?

Thanks for all the information guys.