Caravan hook up

I am not talking about a device cutting out anything with DNO. I was looking at a Viridian EV pen loss connection centre. New to market. A solution to not using an earth rod.

I think UKPN was referring to the device cutting the connection between the caravan and the DNO's earth terminal - which they necessarily must do.


There are a few non-electrode makes of such devices on the market now - which meet the requirements of regulation 722.411.4.1 (iv) for EVs - i.e. the look for a broken PEN (a.k.a. CNE) by checking the L-N voltage and presume a break when it's outside of a +/- 10% of 230V range.


There are a couple of issues - firstly there are some conditions, where a single phase installation is fed from a 3-phase distribution system (which is of course the most common arrangement), where a broken PEN can occur and the N & PE of the installation be raised well above a safe voltage above true earth, but the L-N voltage can remain within the 207-253V range - so they're not ideal where there is any other alternative available. Some manufacturers are building in extra checks (like additionally tripping if there's more than 30mA of protective conductor current) - but still the thing won't necessarily disconnect before someone gets a shock.


Secondly you'd still be connecting the caravan to the DNO's PME earthing facility (when the device hasn't detected a broken PEN) - which the ESQCR has a legal objetion to (OK, technically the legal obligation is on the DNO rather than the consumer, but the DNOs are pretty good at passing the responsibility down via the contractual agreement with the consumer). Yes technically the situation is very similar to charging an EV, but the law (or the wiring regs) hasn't caught up with the technology yet - so it's not much use for a legal and wiring regs compliant solution.


   - Andy.

I am not talking about a device cutting out anything with DNO. I was looking at a Viridian EV pen loss connection centre. New to market. A solution to not using an earth rod.

I think UKPN was referring to the device cutting the connection between the caravan and the DNO's earth terminal - which they necessarily must do.


There are a few non-electrode makes of such devices on the market now - which meet the requirements of regulation 722.411.4.1 (iv) for EVs - i.e. the look for a broken PEN (a.k.a. CNE) by checking the L-N voltage and presume a break when it's outside of a +/- 10% of 230V range.


There are a couple of issues - firstly there are some conditions, where a single phase installation is fed from a 3-phase distribution system (which is of course the most common arrangement), where a broken PEN can occur and the N & PE of the installation be raised well above a safe voltage above true earth, but the L-N voltage can remain within the 207-253V range - so they're not ideal where there is any other alternative available. Some manufacturers are building in extra checks (like additionally tripping if there's more than 30mA of protective conductor current) - but still the thing won't necessarily disconnect before someone gets a shock.


Secondly you'd still be connecting the caravan to the DNO's PME earthing facility (when the device hasn't detected a broken PEN) - which the ESQCR has a legal objetion to (OK, technically the legal obligation is on the DNO rather than the consumer, but the DNOs are pretty good at passing the responsibility down via the contractual agreement with the consumer). Yes technically the situation is very similar to charging an EV, but the law (or the wiring regs) hasn't caught up with the technology yet - so it's not much use for a legal and wiring regs compliant solution.


   - Andy.