240V earthing (2 Viewers)

hilldweller

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Live dangerously - come to Morocco where most outlets don't have eart pins and don't have individual protection either. ELCBs here? Ha.

6 weeks and counting :)

Are the sockets the normal EU ones, either Froggie style or blue ones ?
 

hilldweller

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Its a pity you don't take the time to get to know Olley before making such a derogatory statement Geo

Noble defence but he was quite inaccurate.

But now he's older and wiser.

Or older and more confused because there is no definitive answer to the original question of earthing a genny.
 
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Hi I appear to being slated for my post, without any of the Slater's actually stating what was wrong with it, apart from a sinbads quote taken from a book about very low amperage's killing you.
Thanks for that ringing endorsement Geo, not sure if its justified but the money's in the post. ::bigsmile:

As for my area of expertise, I don't have one, just all round practical knowledge based on over 40 years of working off and on with electrics, but no, I am not an electrician, I am an engineer/heavy vehicle mechanic/plumber/electrician jack of all, master of none. ::bigsmile:

No argument on my part about high voltages and low-ish amperage's killing you, but we are talking here of 230v from a small genny.

Can any of you electrical guys tell me you have never had a shock from 230v mains? and yet you are still here, strange; shouldn't you be dead? I have had plenty and still live to tell the tale. If your stupid enough to wet your hands and firmly grasp the neutral while you hold the live with your other hand then your probably trying to end it all anyway.

Now I was taught all those years ago that AC throws you of, but DC makes you stick to a conductor, making DC far more dangerous, as its AC we are talking about your not like to stick, and all my own shocks have confirmed this so I would think 1/10 of a second is all your hand will be on the conductor for.

Lets look at the question asked: do you need an earth on a small genny? if you intend to walk around on wet grass in your bare feet and grab hold of the outer casing; possibly. If on the other hand you do what 99% of people do and put your shoes on then no. If you happen to have a dicky heart or pace maker then maybe you shouldn't be playing with a genny anyway.

For on board gennys that us RVer's have no point, your cooker becomes live and you touch it, you get a minor shock if anything, your to well insulated from the neutral, stand out side on wet grass and grab the handle if its live, (mines on a fiberglass body so wouldn't be) again you will get a shock but the earth path is through you, through the wet grass and up your tyres to the genny, making a high resistance path.

For you to get a shock you must be in-between the positive and neutral supply, if you are well insulated enough you cannot get a shock just by touching the live conductor.
I watched a guy work on a live 20,000 volt cable once, he sat on a rubber mat and spliced us a new supply from it.

Please if your going to take issue with what I have posted, then base it upon practical experience, not scare mongering from a book. And tell me exactly what you disagree with, not a blanket put me down. You may be right, if you are I WANT to know, this old dog can learn new tricks.

Olley

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hilldweller

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Hi I appear to being slated for my post, without any of the Slater's actually stating what was wrong with it, apart from a sinbads quote taken from a book about very low amperage's killing you. Olley

Slated ? Jumped on :)

If you want reasoned answer....

>> "Hi I think you are worrying un-necessarily, here is my understanding of the situation.
With household electrics sockets you are looking at an almost unlimited momentary amperage before a fuse blows, that's why RCD's are so essential, and its the amps that kill you, with a 1000watt genny only about 4amps, so it will make you jump but its unlikely to kill you."

You know now. MilliAmpres will kill you. So a 4A genny is just as dangerous a 32A ring main fuse.

>> "That's why you can have a shaver socket in the bathroom, your protected from the household mains by a mains isolating transformer, its still 230v but at a much lower amperage so is considered safe."

You know this now. The shaver socket removes the earth from the system which means hand on faulty razor, other hand on earthed tap and you live.

So there is no easy answer, removing an earth in one case saves your life, removing it in another kills you.

Take my little genny. I'm cutting the hedges. I have it running and accidentally cut the cable touching the live wire. I'm in bare feet on wet grass. Do I live ?

Yes - because I did not earth it. Nowhere for the current to flow.

One thing IS CERTAIN, wet is very bad. Dry skin is a bad conductor, wet skin is a good conductor so what you might get away with in the dry will kill you in a bathroom or wet field. The last thing you want is the whole motorhome live which on hook up should be taken care of by the power feed but there is a very good case for a spike, just in case.

I don't have an earth spike :)
 
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sinbad1

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olley

I really don't think anyone is slating you as you say ;but merely pointing out the your earlier thread was not really good advice. i'm the same as you jack of all trades and master of none, and yes years ago we all took risks our our jobs even me and most workers resented safety officers ands proceedures .

Nowdays the rules and safety proceedures are there to protect us, and have probably
saved x thousands of lives .

I am by no means an expert thats why i posted the question for your views .

Olley, i have had a few shocks over the years ;but like you have been lucky some arn't and the statistics of electricution even with gennies out there.

I applologise if you think i was slating you ;but that was not the case

Regards
 

Chudders

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I am a relative newcomer to the forum and do not want to be seen as a clever dick and upset anyone. I am an electrical engineer with a multtude of qualifications and a qualified member (MIET) of The Institution of Engineering and Technology. The Institution of Engineering and Technology - The IET Formerly The Institute of Electrical Engineers. This is the body that administers BS 7671 Wiring Regulations. I specialise in Electrical testing and certification.
I have watched this thread with interest and there are some interesting views, some are accurate and some are less so but I do not intend to put the cat amongst the pigeons by praising some and not others.
Since the electrical safety of our motorhomes and more importantly its occupants is paramount and as there is clearly some interest I will if you wish in time start another thread with the requirements of site electrical safety and requirements and with particular regard to motorhomes and caravan hook up points, including earthing arrangements. I have no wish to hi jack this topic.
It is a very complicated subject but without wanting to upset those that have knowledge will try to keep it in laymans terms so that everyone has some knowledge of what is safe and satisfactory.
Believe me I have seen some horendous electric hook up installations and would not dream of connecting my motorhome to them let alone provide them with a satisfactory certificate..
Regards, David.

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sinbad1

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Hi Chudders

I originally started this thread because i was unsure of the safety regarding the earthing of onboard generators, as previously said its not been conclusive so i am erring on the safey side.

Your are welcome to continue this thread, any constructive input is allways welcome.

Regards
 

scotjimland

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I disagree with this statement, but wonder what others think?

Olley

Hi Olley

A 4A genny is more than capable of killing you, 30ma is considered to be the upper safe limit , over 100ma is lethal if it passes across your heart or brain, ie arm to arm or arm to leg, whether the power is supplied by the EHU or the genny, the shock and the consequences will be the same.. you may lucky and get off with a 'belt' or be killed

So I would have to agree with the statement.

There are plenty of articles on the net re electrocution, this one from Wiki is quite good.

Electric shock - Wikipedia, the free encyclopedia

Jim
 

American Dream

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I was always trained to respect electricity.

We used to work with 50 volts but capable of thousands of Amps.Saw a spanner vaporised once and the user taken to hospital with bad burns and shock.

My rule is, If it involves electricity in any way, I make sure it's earthed and treat it with the utmost respect.My Family safety is paramount.

I always check the site earth and polarity on ehu and earth the genny when running.

230v at just a few milliamps in the wrong circumstances can cause death as Jim has said.

My Genny has a small earth screw on it.I run a cable to a metal skewer to earth.
 
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hilldweller

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I disagree with this statement, but wonder what others think?

Olley

Is that disagree that you were jumped on or disagree that 4A is as dangerous as 32A ?

Since you are the one asking for reasons then do the same.

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scotjimland

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We used to work with 50 volts but capable of thousands of Amps.Saw a spanner vaporised once and the user taken to hospital with bad burns and shock.



Indeed.. Steve

Statistically there are more injuries from 'flash' burns than electrocution, many from batteries where people tend to be more careless, a short across a metal wrist watch strap can give a serious burn requiring hospital treatment..

Some years ago my dad suffered a serious flash burn to both hands when closing an old fashioned open frame 11kv transformer switch.. the injuries took many months to heal.

Play it safe.. respect all electrical supplies whether 12v or 230v , they are equally dangerous albeit in different ways..
 
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hilldweller

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I specialise in Electrical testing and certification. Regards, David.

Come on David, don't keep us waiting.

You've seen my views, I don't think one rule fits all, so what is the best all round practice ?

Just to be awkward in 6 weeks we, and a few others in here, will be parked up in the wet windy hell of England/France and a few weeks later in the Sahara :)
 
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sinbad1

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Play it safe.. respect all electrical supplies whether 12v or 230v , they are equally dangerous albeit in different ways..[/quote]

I agree Jim, houses have 230V, motorhomes have both 12v and 240v which i guess increases the potential hazards.

I am suprised that there is no mandatory safety certificate for motorhome habitation.

I lived on a boat for 15yrs , to be able to get a license the boat had to have a certificate of compliance (COC), the list covers many area's tested and checked before a certificate is issued.

battery setup/corgi test gas leak and configuration/ventilation/240v system, etc

Interestingly
If you had a gennerator onboard you would not be issued with a certificate
(Petrol vapour hazard in confined spaces )

Perhaps another thread

Regards

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OK just one agrees with me ::bigsmile:

My belief that the amps do make a difference is to me logical, consider this:

I am hit by a car doing 5 miles an hour, now it has the potential to kill me but in practice it probably won't, increase the speed of the car and my chances of survival steadily decline.

Now to my logic, amps work in exactly the same way, get enough of them and they will actually fry you as they boil your blood.

True story: On a safety course at Sizewell Nuclear power station, we were told about a maintenance worker who stood on a high voltage cable tray, somehow he broke through the cable insulation with his shoes, at the autopsy it was noted that both his knee caps had been blown off.

Olley
 

thehutchies

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I am hit by a car doing 5 miles an hour, now it has the potential to kill me but in practice it probably won't, increase the speed of the car and my chances of survival steadily decline.

Now to my logic, amps work in exactly the same way, get enough of them and they will actually fry you as they boil your blood.


Olley

In this example, though, the speed of the car is analogous with the voltage, rather than the current. The higher the voltage, the greater the current that will pass through the given resistance of your body.
 
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Thanks papa, this basically confirms what I have been saying, the amps do make a difference, 4amps possible death, 10amps probable death.

I will hold my hands up and say that 4 amps is more dangerous than I thought.

However I will also say that IMHO driving an earth stake into the ground is over the top, 24 people died last year by electrocution, whereas 2946 died on the roads, so it seems to me you are more likely to die driving to the site than from an electrical fault when you get there.

Olley
 

pappajohn

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Thanks papa, this basically confirms what I have been saying, the amps do make a difference, 4amps possible death, 10amps probable death.

I will hold my hands up and say that 4 amps is more dangerous than I thought.

However I will also say that IMHO driving an earth stake into the ground is over the top, 24 people died last year by electrocution, whereas 2946 died on the roads, so it seems to me you are more likely to die driving to the site than from an electrical fault when you get there.

Olley
no probs Olley,

obviously too many variables to say what WILL kill you and what WONT.....wet hands, rain, standing in a bath of water changing a light bulb....:ROFLMAO:
 

Tony Lee

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Thanks papa, this basically confirms what I have been saying, the amps do make a difference, 4amps possible death, 10amps probable death.

Olley

Hmmmm! OK Olley. I think it might be best to leave you in your blissful state when it comes to the black art of electricity. However it might be safer for everyone if you keep your electrical expertise to yourself rather than sharing it.

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Hmmmm! OK Olley. I think it might be best to leave you in your blissful state when it comes to the black art of electricity. However it might be safer for everyone if you keep your electrical expertise to yourself rather than sharing it.

Hi Tony, so your reply is another "slate" you have no idea of my electrical capabilities, I could question yours but this is a FUN site, so I will stick to defending myself.

I have rewired houses, built old fashioned inverters, built single and three phase sunbeds which involved shorting out power factor correction, so I consider my basic electrical knowledge pretty good. I can say that with confidence, as the recent rewires were for a local landlord who then had them certified by an electrician. But then rewiring a house is not hard.

So no I won't keep my electrical expertise to my self, but maybe you should stop being so condescending? none of us knows everything, and just because you were a teacher doesn't make you superior to me or anybody else.

There's an old saying "those that do; do, those that don't teach"

Olley
 

hilldweller

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24 people died last year by electrocution, whereas 2946 died on the roads, Olley

That puts it into perspective even more that the figures indicate.

Every man woman and child is exposed to electrical danger all day, every day. Whereas I'd guess the average time in a vehicle per day less than an hour a day.
 

pappajohn

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Hmmmm! OK Olley. However it might be safer for everyone if you keep your electrical expertise to yourself rather than sharing it.



Hi Tony, so your reply is another "slate"

Olley

got to agree with Olley, there is certainly more than a lttle 'slate'-ism in that post.:Sad:

if a 17th edition inspection and test NIC-EIC qualified electrician gave a definative answer would you get a second opinion incase he was wrong?

probably......

others have pointed out what they think are Olleys mistakes and left it at that...end of disagreement.

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hilldweller

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Come on David, don't keep us waiting.

You've seen my views, I don't think one rule fits all, so what is the best all round practice ?

Just to be awkward in 6 weeks we, and a few others in here, will be parked up in the wet windy hell of England/France and a few weeks later in the Sahara :)


This seems to have got lost, I don't see any definitive reply.
 

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