Earth on inverters

Discussion in 'Motorhome Chat' started by Reallyretired, May 2, 2012.

  1. Reallyretired

    Reallyretired Funster

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    My mains sockets are wired through a 1.5kw (continous)charger/inverter/UPS so that whether or not connected to EHU I always have mains available.

    While connected to EHU, even if there is a power cut, there is still an earth on the 3 pin sockets, however when not connected and supply is totally from inverter the sockets will show an earth fault. This is not surprising of course as there is no connection to earth in this case.

    Does the panel see any virtue in connecting the mains wiring earth to an earth spike so that appliances will stil be earthed even when there is no connection through EHU?

    I have also found some site electric connections abroad do not have the earth connected, even if there is in theory an earth pin.
     
  2. Gromett

    Gromett Funster

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    I had a relay on my previous van which the neutral to the chassis if the inverter was on and no EHU was connected. I am going on memory here so don't just jump in with this.

    I seem to recall that if no earth was present connecting neutral to the chassis gave you an effective earth for the breakers.

    I will dig out my notes on this and get back to you with the details.
     
  3. aba

    aba

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    i have been advised by a friend that when running a generator its good practice to earth spike the van as it is possible that when you put a foot onto the aluminium retractable step and one on the ground you could get a shock if there is a fault.

    i see no difference with an inverter although i am looking at some method of grounding the van without a spike maybe a couple of those car sickness strips that fasten on the underside of the car and touch the road.
     
  4. pappajohn

    pappajohn Funster Life Member

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    if the generator is stood on ground likely to get wet then an earth spike is a good idea.

    the vans earth circuits are earthed to the genny casing so if the genny is clear of ground, or on dry ground, (the genny is insulated by the plastic case or rubber feet) there is no earth path to the ground (its an internal earth) so stepping out of the van will make no difference.

    if you fit an earth spike to the genny you should also fit an earth spike to the vans chassis or stepping out of the van while touching a live appliance will make you the earth point to ground.

    this is one time an earth can be dangerous.
     
  5. pappajohn

    pappajohn Funster Life Member

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    those things will only discharge static electric and wont work as an earth point for mains.....unless they are wet through.
     
  6. hilldweller

    hilldweller Funster Life Member

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    Speaking theoretically, don't do this at home, if you connect the 240V live from your inverter to the van body you can safely get in an out in bare feet. There is no path for the current.

    With a gennie. Connect 240V to body. No return path. But earth the gennie then you get a belt when you climb in.

    Food for though, is an earthed genny more or less dangerous than a non-earthed one.

    A bit on the Stirling site says it is now required to link N-E on inverters. That makes it like the standard mains.
     
  7. pappajohn

    pappajohn Funster Life Member

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    well i got that right for once.

    but if you also earth spike the van as well, then you still wont get a belt as its already earthed better than you are.

    all this is immaterial anyway as the RCD in the vans fuse box should already have tripped if theres an earth fault via the genny earth circuit :Doh:
     
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