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Caravan hook up
Former Community Member
Hi I am fitting a caravan hook up on the wall next to the dno incomer box. No wires exposed. Do I still require an earth rod. The earth bond will be prob 1 ft long inside so not exposed. I know if I fit the box away using swa then yes earth rod would be used.
The complication with caravans is that the ESQCR prohibits the use of a PME earth connection for a caravan (or boat) - and since UK DNO's are liable to interconnect N and PE during network alterations the only safe policy is to assume that every DNO supplied earth terminal could be PME (unless there's been explicit assurance from the DNO otherwise). So generally the caravan socket will need to be connected to a TT system and separated from any DNO's earth facility. If the installation is already TT, then it's simple and no extra rod is required - it can just share the installation's.
Driving in a new rod will of course require a lot of care - not just from the risk of hitting exiting buried services (quite likely if you're next to a meter box and the supply is underground...) but really you should keep the rod well away from any underground metalwork that's connected to the PME system (old gas and water pipes, or lead sheathed cables for instance) otherwise you still have the same problem of the caravan's earthing system being taken to hazardous voltages should the supply CNE go open circuit. Ideally it should be subject to the same potential as the ground the caravan will be stood on, but that isn't necessarily straightforward when buried metalwork can have an influence over a much shorter distance than the length of a caravan.
Electric vehicle charge points have the same problem - and for them there is an option of using the PME earth together with a device that disconnects everything (L, N & PE) if an open-CNE is detected. They are a little controversial however (especially the single phase L-N voltage monitoring types) and as far as I know aren't recognised by the regulations for use with caravans.
The complication with caravans is that the ESQCR prohibits the use of a PME earth connection for a caravan (or boat) - and since UK DNO's are liable to interconnect N and PE during network alterations the only safe policy is to assume that every DNO supplied earth terminal could be PME (unless there's been explicit assurance from the DNO otherwise). So generally the caravan socket will need to be connected to a TT system and separated from any DNO's earth facility. If the installation is already TT, then it's simple and no extra rod is required - it can just share the installation's.
Driving in a new rod will of course require a lot of care - not just from the risk of hitting exiting buried services (quite likely if you're next to a meter box and the supply is underground...) but really you should keep the rod well away from any underground metalwork that's connected to the PME system (old gas and water pipes, or lead sheathed cables for instance) otherwise you still have the same problem of the caravan's earthing system being taken to hazardous voltages should the supply CNE go open circuit. Ideally it should be subject to the same potential as the ground the caravan will be stood on, but that isn't necessarily straightforward when buried metalwork can have an influence over a much shorter distance than the length of a caravan.
Electric vehicle charge points have the same problem - and for them there is an option of using the PME earth together with a device that disconnects everything (L, N & PE) if an open-CNE is detected. They are a little controversial however (especially the single phase L-N voltage monitoring types) and as far as I know aren't recognised by the regulations for use with caravans.
