Are you saying your supply does not comply with Regulation 27 of ESQCR

I've known sites where the, er, 'tolerance of measurement' has been debated - i.e. several UPSs (programmed for 253V max) regularly complained of over-voltage and switched into 'buck' mode, while the DNO's power quality meters insisted it wasn't quite exceeding 253V. Even a tenth of a percent difference is measuring devices can be very significant in these borderline cases.

 

The new method requires no earth terminal, and  is by using a device that  removes the car from the charger by opening of L, N and E  if the L-N voltage goes out of spec,

i.e.  over 253 or below 207V for more than 5 seconds.

They also seem to be sneaking in a new method of shock protection - i.e. a non-separated separated system with lots of extra RCDs to try and make up for the inherent deficiencies.



Many of the PME approaches seem to presume that an open CNE fault can only occur in the cable serving a single installation. I'm not sure that's sensible. I'm sure I've seen a document somewhere that listed amongst other things the average number of customers affected by different types of distribution network faults - more than likely linked to from this (or the old) Forum. Can anyone remember where it might be?


   - Andy.

Are you saying your supply does not comply with Regulation 27 of ESQCR

I've known sites where the, er, 'tolerance of measurement' has been debated - i.e. several UPSs (programmed for 253V max) regularly complained of over-voltage and switched into 'buck' mode, while the DNO's power quality meters insisted it wasn't quite exceeding 253V. Even a tenth of a percent difference is measuring devices can be very significant in these borderline cases.

 

The new method requires no earth terminal, and  is by using a device that  removes the car from the charger by opening of L, N and E  if the L-N voltage goes out of spec,

i.e.  over 253 or below 207V for more than 5 seconds.

They also seem to be sneaking in a new method of shock protection - i.e. a non-separated separated system with lots of extra RCDs to try and make up for the inherent deficiencies.



Many of the PME approaches seem to presume that an open CNE fault can only occur in the cable serving a single installation. I'm not sure that's sensible. I'm sure I've seen a document somewhere that listed amongst other things the average number of customers affected by different types of distribution network faults - more than likely linked to from this (or the old) Forum. Can anyone remember where it might be?


   - Andy.