A question for the electricians - earthing the 240v consumer unit

Discussion in 'Mech Tech' started by baygeekster, May 12, 2014.

  1. Quick question - now I have completed wiring up my 240v electrics, I know I should also connect the earth terminal to the body of the van, otherwise, if the van body ever becomes live through a loose or frayed wire, it could become a handy kentucky-fried-person device. So, what sort of cable do I need to connect the earth side of the consumer unit to the van body? (If that isn't an obvious question).
     
  2. Razzyh

    Razzyh Supporter

    It's the normal earth cable that you'd use for home electrics.
     
  3. 4 or 6mm2 Green/Yellow stripe.
    Connect it from the Earth terminal in the consumer unit to a new point on the bodywork/chassis. Don't share the earth point with the 12V system.
     
    Dicky likes this.
  4. What MarcT512 said ^^

    single core 4 or 6mm2 Green/Yellow stripe :thumbsup:
     
  5. theBusmonkey

    theBusmonkey Sponsor

    Sorry to jump in here @Diddymen but are you sure (ie 100% sure) that single core is best practice?
    I'd always been led to believe (& believe me I'm no expert on leccy) that on any vehicle, caravan, motorhome, boat etc where vibration is present that multi-strand flexible cable is to be used.

    It's probably different for campers but there is no way we would recommend a single core earth for bonding boat hulls to earth. If the single core breaks in the sheath due to vibration, there is an earth fault, then protection is lost. It's all generally hypothetical anyway, but I'm interested in the regs for motorhomes/campers etc. :thumbsup:
     
  6. domestic ,
    4mm and 6mm earth cable will be multi strand,
     
  7. ...single core is where the cable consists of a single insulated conductor. There may be an outer sheath for mechanical protection..... the conductor itself may be solid or multistranded.
     
    Diddymen and theBusmonkey like this.
  8. A "fine" stranded flexible wire would be best. Something like "Tri-rated singles, BS6231 class 5 flexible" (or H07V2-K, H07V2-F or H07R-F in the harmonized code.)

    For example:
    http://www.tlc-direct.co.uk/Products/CA4TRGY.html

    I've probably got some off-cuts if you need. PM me and I can post a short bit to you.
     
  9. Whats the issue with sharing the earthing point?
     
  10. rickyrooo1

    rickyrooo1 Hanging round like a bad smell

    i wondered this as mine does......
     
  11. I would imagine that it gives the load a chance to dissipate throught-out the body of the vehicle, and back to the supply protective device, before it frys your 12v electrics...
    :gnome:
     
  12. I can't think of any...
     
  13. It's a regulations thing - the IEE Wiring regs stipulate the cables for the mains and ELV (Extra Low Voltage, 12V) systems must be run separately. Therefore they shouldn't meet at a common earth point.
     
    SeanOC likes this.
  14. what size is the earth wire on your mains hook up supply ?
     
  15. Mines 4mm singles to an 8mm bolt through the wheel arch.
     
  16. Do you mean the actual hook up cable? If so, 2.5mm2 three core flexible cable is recommended. The earth is therefore 2.5mm2.
    The earth bond in the van should be no less than 4mm2. I think mine is 6mm2 and goes from the consumer unit earth strip to an M8 bolt through the floor.
     
    SeanOC likes this.
  17. theBusmonkey

    theBusmonkey Sponsor

    Thanks @fritt , as I said I'm no lectrician & apologies for questioning your earlier answer @Diddymen :thumbsup: Always learning....
     
    Diddymen likes this.
  18. Is this specifically for campers?
     
  19. Caravans - but for campers/motorhomes the same applies.

    Some useful info here - this is a guide to the regs for caravan installs:
    http://www.tlc-direct.co.uk/Book/7.9.2.htm
     
  20. lol no probs mate :thumbsup: ...there no such thing as a silly question especially when electrics are concerned

    conductor and core are slightly differing terminologies and @fritt has explained it better than me lol!!! ....I can see where it is easy to get confused though


    the definition from the wiring regs is:-

    Types of wiring system-

    insulated single core cables, with flexible class 5 conductors run in non metallic conduit

    insulated single core cables, with stranded class 2 conductors (min of 7 strands) run in non metallic conduit

    sheathed flexible cables
     
    MarcT512 likes this.

Share This Page