Caravan TT system hook up point.

[dogwind]

Hi i was wondering what the downside to connecting the earth to an earth rod TT system AND to the TNCS from which the supply is being fed from, i understand that in the fault of the pme neutral going down that a caravan could become live under fault conditions but surley 2 earth paths would be safer than the TT alone which as we all know is dependant on how moist and conductive ground is around the earth rod. Can anyone tell me what the dangers are of connecting to both earth systems.
Thanks

 

[truckster]

You should not mix earthing systems as PME currents may use your TT as an earth path and as you say the potential of the caravan may rise. The ESQC regs prohibit connecting a PME system to a caravan and BS7671 also prohibits connecting PME to any pitch outlet.

 

[dogwind]

Thanks for your reply truckster, I did see in the regs it isnt allowed to be a PME so i wasnt going to connect it anyway but just wanted to know the dangers of connecting to both TT and PME, I didnt think of it using the TT caravan hookup point and caravan as the PME earth path but now it all makes sense.
Cheers for the advice