# Generators - earthing question



## asprn (Feb 10, 2006)

We got a polarity checker before going to France in May, and I noticed that it showed a "no earth" light when the genny was running. I was fairly sure it wasn't a fault as such and ignored it, but on thinking about it, how does a genny earth, and why does the checker show a "no earth"?

Dougie.


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## urbanracer (Aug 22, 2007)

If you read the generators instruction it will say you need to have an earth wire that you attach to a metal tent peg or similar and pushed into the ground.

Thats how it should be but I have never done this.


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## DABurleigh (May 9, 2005)

Dougie,

As a techie I recommend you forget about motorhome earthing issues - that's if you value your sanity. I consciously don't go there as I value what's left of mine.

Dave


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## asprn (Feb 10, 2006)

DABurleigh said:


> As a techie I recommend you forget about motorhome earthing issues - that's if you value your sanity. I consciously don't go there as I value what's left of mine.


lol - not the answer I expected.  So a can of worms, _Peut-Être?_

Might be a conspiracy to get rid of me, of course...... 8O

Dougie.


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## smithies (Jul 1, 2007)

My Dometic genny in our now sold Autotrail was the same , the installer assured me thats the way it works..... I made up an earthing wire and used that.....


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## LPDrifter (Aug 17, 2005)

DABurleigh said:


> Dougie,
> 
> As a techie I recommend you forget about motorhome earthing issues - that's if you value your sanity. I consciously don't go there as I value what's left of mine.
> 
> Dave


Hmmm a deeply philosophical answer. :lol: :lol:


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## 104477 (May 13, 2007)

LPDrifter: keep watching this space but it don't change ! Are you trying to get a rise out of us non public school types? It won't work you know....Oh B**ger, you win!


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## LPDrifter (Aug 17, 2005)

rapidorob said:


> LPDrifter: keep watching this space but it don't change ! Are you trying to get a rise out of us non public school types? It won't work you know....Oh B**ger, you win!


Ahh Rapidrob that's a deeply philosophical avatar :wink:

LPDrifter (non public school type)


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## 96783 (Nov 23, 2005)

In my army days we ran 22.5Kva diesel Lister gennies 24 hrs a day to run all sorts of specialist equipment - no problem boiling a 3Kw kettle but noisy and smelly. They had a socking great big earth spike and you wouldn't dream of not using it. Now why would that be if it isn't necessary for your safety and the safety of your precious and expensive electrical system?


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## asprn (Feb 10, 2006)

PhredC said:


> Now why would that be if it isn't necessary for your safety and the safety of your precious and expensive electrical system?


Dunno - you can tell us though. 

Dougie.


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## 96783 (Nov 23, 2005)

I actually don't know the answer! My guess, and it is 
only a guess, is that relying on the vehicle's own earthing system is not considered sufficient by the gennie manufacturer. I confess that I was hoping that one of our more technically minded readers would be able to give a definitive answer. Dave B clearly has strong views about not viisiting earthing spikes. My question was a serious question, not a put down (or up for that matter)!


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## DABurleigh (May 9, 2005)

Don't get me wrong. My only reluctance is that the subject really, really makes my brain hurt. I'm more than happy for someone to explain practical minimum safety compliance for genny/inverter/RCD/earthing use in a context of motorhomes, but everything I've seen on the subject so far just doesn't hang together.

Dave


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## geraldandannie (Jun 4, 2006)

Is it something to do with the van being on rubber tyres, and therefore isolated from earth? Is it something like the "double insulated" mains-powered hand drills (Black & Decker etc)? They don't have an earth - just a plastic prong.

Maybe the likelihood of having a part of your body touching a live socket and the earth (the other side of the aforementioned rubber tyres) is so slim, nobody worries about it.

TBH, I'd never thought of it before. Then again, the use of gennies at all is another topic ... :wink: 

Gerald


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