Using a generator.

Discussion in 'Tech/Mech General' started by dogman, Nov 1, 2013.

  1. dogman

    dogman Read Only Funster

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    This may be a pretty stupid question BUT how many earth their generator? I have used generators on and off for many years but NOT for an MH. When using EHU you are earthed back to source but not so with a generator, is there a danger of static build up:Eeek:. The instructions say earth the genny out so earth it out it will be but who else earths theirs out?
    Many thanks for any replies.
    Cal
     
  2. buffallobill

    buffallobill

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    i do.:thumb: .....with a length of wire from earth screw on genny to a thick steel tent peg , either knocked into ground or if on hard standing put the genny on top of earthing peg..
     
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  3. pappajohn

    pappajohn Funster Life Member

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    if the generator isnt 'earthed' to ground there is no return earth path from the van.

    number 1 safety advise to digger drivers....if you hit a cable DO NOT get off your machine as you become the earth path.

    if you earth the genny you need to earth the van as well or in a fault situation you step out the van you become the earth return path.

    on generator power i would sooner not have an earth.

    using an earth spike requires quite detailed knowledge for it to work correctly....just banging a metal rod in the ground isnt good enough.

     
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  4. bobandjanie

    bobandjanie Funster Life Member

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    And if your holding the earth spike while hitting it with your club hammer, and it goes through an under ground electric cable, :Wink: your history. :Eek!: Bob.
     
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  5. Wildbill

    Wildbill Funster

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    and i see so many that don't even bother and sum that put in a tent peg in to bone dry ground and have seen one with earth in to a bucket of earth:Rofl1: i prefer to use a coper shrouded piece of 8mm 10mm coper pipe thread bar in to the ground at least 2 ft more if possible to pick up the damp ground in to dry soil you may as well not borther
    then make the ground wet around the peg best place i have fund is where my gray water drips out then you don't nead to keep poring water on the aria.
    i don't use a genny much now but that was my way may be wrong but sum earthing is better than no earthing
     
  6. haganap

    haganap Funster Life Member

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    Wow, in ten years I've never earthed my genny....

    I've never worried about reverse polarity neither


    I'm such a dangerous man :Cool:
     
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  7. pappajohn

    pappajohn Funster Life Member

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    the mechanics or testing an earth spike for correct functionality

    no good just banging a metal rod in the ground
     

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  8. cmcardle75

    cmcardle75 Read Only Funster

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    Don't worry about it. A motorhome using a gennie is basically using IT earthing, which isn't a particularly bad system, especially when using predominately double insulated appliances.

    Make sure you have an RCD. And if you suspect a fault, jump down from the step double footed, rather than stepping down...
     
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  9. Snowbird

    Snowbird Funster Life Member

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    In all the vans I have owned when running a genny there has never been an earth light on the polarity tester. But the van I have now shows an earth not only on the genny but on the inverter. Everything is wired through a shunt, would this make a difference.
     
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  10. Ed Excel

    Ed Excel Funster

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    When using a generator, why install an earth spike, the machine is connected to your MH by cable. There is nothing supplying the generator, so an earth return path is not required.

    An earth cable is provided to return fault currents to their source, which in the case of a generator is the generator.
     
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  11. dogman

    dogman Read Only Funster

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    Having trouble posting, evidently my post is too short, it should be at least 1 character despite being several sentences??? Not sure what's going on at all, I have closed then and reopened MHF, also closed multiquote, any suggestions please.
     
    Last edited: Nov 2, 2013
  12. dogman

    dogman Read Only Funster

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    if the generator isnt 'earthed' to ground there is no return earth path from the van.
    This is the way I see it.

    if you earth the genny you need to earth the van as well or in a fault situation you step out the van you become the earth return path.
    I see no point in this as the earth return will be via the cable direct to the genny.

    on generator power i would sooner not have an earth.
    Can you please explain for the benefit of others contributing to this thread.

    using an earth spike requires quite detailed knowledge for it to work correctly....just banging a metal rod in the ground isnt good enough.
    I think banging a rod into suitably wet ground would be good enough.

    Many thanks for your time and trouble in answering my query, I'm sure others have learned from you and other posters.

    Don't worry about it. A motorhome using a gennie is basically using IT earthing, which isn't a particularly bad system, especially when using predominately double insulated appliances.
    No idea what an IT system is, can you please briefly explain.

    Make sure you have an RCD.

    A good point, one I had NOT considered but will now.
    And if you suspect a fault, jump down from the step double footed, rather than stepping down... Not so easy getting back in though.:Rofl1:
    When using a generator, why install an earth spike, the machine is connected to your MH by cable. There is nothing supplying the generator, so an earth return path is not required.
    But the earth return is via that cable and terminates at the genny, without an earth cable it has nowhere to go.

    An earth cable is provided to return fault currents to their source, which in the case of a generator is the generator.

    Exactly my point.
     
  13. dogman

    dogman Read Only Funster

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    Well it's obvious there is a lot of knowledge and experience out there together with differing opinions, thank to those who have taken the time to reply, I'm sure many have learnt something but keep the knowledge flowing as this earthing business is an important safety issue for all motor homers and those over on the "dark" side (caravanners:Eeek:).
    Regards
    Cal
     
  14. dogman

    dogman Read Only Funster

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    Well the only way I could get round this was to copy the post I wanted to quote, paste into word and add my comment, then copy it back to MHF, not sure why but got there in the end.
    Cal
     
  15. jonandshell

    jonandshell Funster

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    OK, if your van is live due to a fault, and and you use an earth spike on your Genny, when you step out of the van you die.

    If you don't earth your plastic enclosed genny and your van is live, you step out of your van, there is no circuit to complete and you don't die.

    Of course this assumes the tyres are nice and dry and aren't conductive!

    I think all motor caravanners should wear industrial nonconductive wellies, always!

    However, your van won't go live in any case because your earths all go back to the Genny neutral. A live to earth connection results in a dead short and a blown trip. Problem solved!
     
  16. dogman

    dogman Read Only Funster

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    OK, if your van is live due to a fault, and and you use an earth spike on your Genny, when you step out of the van you die.
    Surely if the circuit is complete via the earth cable from the genny to the ground the MH can't become live??
    If you don't earth your plastic enclosed genny and your van is live, you step out of your van, there is no circuit to complete and you don't die.
    To me this is the opposite to what would happen but I am NOT an electrician.


    Of course this assumes the tyres are nice and dry and aren't conductive!

    I think all motor caravanners should wear industrial nonconductive wellies, always!

    However, your van won't go live in any case because your earths all go back to the Genny neutral. A live to earth connection results in a dead short and a blown trip. Problem solved!
     
  17. jonandshell

    jonandshell Funster

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    Point one, yes!

    Point two, you are electrocuted when you form a circuit from live to neutral. In your house, or a campsite, all neutrals are connected to earth at the sub station. In our house, due to the dry sandy soil we are on, our earths are connected to neutral at our house, a Protective Multiple Earth, or PME system. When you touch a live wire, you are connecting it through yourself, through the ground under your feet, to neutral at the substation.

    When using a generator, your van is 'earthed' via your hookup lead, to the neutral of the generator. You will not form a circuit to actual earth, by touching a live wire, unless you use an earthing spike on your generator. Even if your van did become live by means of a faulty hookup lead, simply touching actual ground will not result in a shock because your generator neutral is not connected to the ground it is sat on.

    Does that make sense?

    This whole earthing business is not a problem in most countries, its just us trying save money by having the planet used as the neutral connection for the national grid rather than putting a fourth cable on our pylons!:BigGrin:
     
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  18. Ed Excel

    Ed Excel Funster

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    With you on the other points but this last one isn't quite correct. The supply to your house is by 4 core cable from a star connected transformer with a centre tapped earth, in a secondary substation. The supply to the sec. sub. is by 3 core cable from a delta connected transformer with no earth, in a primary sub. Earth faults are transmitted back to the sec. sub. and then appear as load on the primary. I'll bet not a lot of people wanted to know that!! :Eeek:
     
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  19. JJ

    JJ Funster

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    I sometimes use a genny.

    I never, ever earth the genny.

    If this causes my death please feel free to say "I told you so..."

    Many, many times I drive along a road in a motohome. Now that really is putting me and any passengers in danger.

    JJ :Cool:
     
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  20. jonandshell

    jonandshell Funster

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    Deffo 2 core cable to our gaffe, its via an overhead cable.

    Had it renewed last year!:thumb:

    Our earths all connect to neutral via the distribution board to the lock off.
    Its because the the earth impedance is too high due the dry land round here.

    Not many underground cables round here!:BigGrin:
     
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