Earth Rod attached to motorhome...any unforseen detrimental effects?

[John Frum]

Moving RV. He envisions a short earth rod pounded in with a hammer and soaked with water. I dont fancy the idea myself, but everyone says that i must get the system 'checked out by a qualified electrician', but having done so, i'm now getting told frequently that he is wrong in his assertions.

I'm sorry to say that I'm rescinding the offer to camp in my driveway
We can still hang out though.

 

[Samueru]

In a rubber tyre insulated motorhome, is there any downside to attaching an earth rod to the chassis when parked up, when using 240v ac inverter power only(no grid tie or grid earthing) ?
Is it safer with the earth rod connection or not?

Without it.

Thanks for all the replies folks. I have an electrician friend that insists i need an earth rod for the RCD to work.

Are the RCDs not tripping when you press the test button?

Looks like this is the UK, there they have what is known as TT system, they do in fact sometimes use the earth as EGC, but because the earth resistance is too high the upstream breaker needs to have RCD protection, otherwise a ground fault would only make things more dangerous.

IIRC TT is no longer being used in the UK.

They likely are trying to apply the logic of TT systems here.

@Boondock Saint

Thanks for your reply boondock saint...

I thought i had all the grounding worked out, but a qualified electrician friend has thrown a spanner in the works by insisting that i need an earth rod for RCD protection.

As regards boats, if they have a metal hull, would this not conduct through the water back to earth?

The reason i keep asking questions as im getting so much conflicting information and i'm paranoid about electricity. I need to be 100% confident my vehicle is safe, not 99.9%

See my rough earthing drawing of current setup...care to comment?View attachment 53057

What is SCC?

Are you sure the inverter has a neutral to earth bond inside? If that's the case then the diagram is 100% safe. If the inverter does not have the bond RCDs will not work, but that does not mean that it is not safe 100%, other european countries allow you to have ungrounded systems, no idea if in the UK you can.

When you have an ungrounded system there is no potential between live and chasis, meaning that you cannot get a shock by touching just the live wire, you would need to touch both live and neutral and nothing can protect you against that, not even RCDs with a grounded system.

 

[12VoltInstalls]

Best to ask here: https://forums.mikeholt.com/forums/bonding-and-grounding.22/

Holy cow
I’ve not run across that before but the paragraphs I just read are simply fantastic. It’s like the engineer’s knowledge viewed with the eyes of an electrician and spoken in plain English with not just the rule, the how, snd the why, but also the dangling “because” context that so often gets missed.
i can write like that about a few subjects but not general electricity (or at least not NEC stuff regarding 120VAC).
I am impressed. ‘Because you’re supposed to’ has never been an adequate explanation to me for anything.