Details of BS7671:2018 Amendment 1 are here.

lyledunn:

I wonder how common loss of neutral is in U.K. systems.

On average about 1 per day is actually reported. No-one knows how many go unreported. The real number therefore exceeds this, but it's impossible to know by how much. The load unbalance downstream of the broken neutral determines the potential touch voltage - this changes over time, so the Neutral is shifting around all over the place. The effectiveness of fortuitous earthing from extraneous-conductive-parts of installations also impacts this, but worth noting  that this is reducing in effectiveness over time as metal pipes are (necessarily) being replaced with plastic.

It's also unknown how many people get shocks but don't report them.

Thumping in compensatory electrodes ain’t going to do much to reduce risk of collision with underground cables, gas pipes and the like.

And the achievable resistances often means the requirements of 722.411.4.1 for additional earthing can't be met.

The solution has got to be as close to simple plug and play as possible in order to facilitate safe roll out of the EV infrastructure.

Perhaps the changes in 722.411.4.1 make this more achievable -  although as others have pointed out in this thread, in some cases it will depend on what DNOs consider acceptable - particularly for on-street installations. In reality, as has also been pointed out, some of it is in the standards for the vehicles and chargers, which are outside the scope of BS 7671. Other countries don't have the same concerns about PME - but they implement their versions of PME in different ways, with different network configurations than the UK.  There are other countries where there appear to be more issues with PME in general, regardless of EV charging - one example is Australia.

Accepting the TN-C-S risk requires a solution, an even bigger risk is likely to come from fire due to the higher amperage sustained loads, especially in dwellings where inspections may never be made.

 

lyledunn:

I wonder how common loss of neutral is in U.K. systems.

On average about 1 per day is actually reported. No-one knows how many go unreported. The real number therefore exceeds this, but it's impossible to know by how much. The load unbalance downstream of the broken neutral determines the potential touch voltage - this changes over time, so the Neutral is shifting around all over the place. The effectiveness of fortuitous earthing from extraneous-conductive-parts of installations also impacts this, but worth noting  that this is reducing in effectiveness over time as metal pipes are (necessarily) being replaced with plastic.

It's also unknown how many people get shocks but don't report them.

Thumping in compensatory electrodes ain’t going to do much to reduce risk of collision with underground cables, gas pipes and the like.

And the achievable resistances often means the requirements of 722.411.4.1 for additional earthing can't be met.

The solution has got to be as close to simple plug and play as possible in order to facilitate safe roll out of the EV infrastructure.

Perhaps the changes in 722.411.4.1 make this more achievable -  although as others have pointed out in this thread, in some cases it will depend on what DNOs consider acceptable - particularly for on-street installations. In reality, as has also been pointed out, some of it is in the standards for the vehicles and chargers, which are outside the scope of BS 7671. Other countries don't have the same concerns about PME - but they implement their versions of PME in different ways, with different network configurations than the UK.  There are other countries where there appear to be more issues with PME in general, regardless of EV charging - one example is Australia.

Accepting the TN-C-S risk requires a solution, an even bigger risk is likely to come from fire due to the higher amperage sustained loads, especially in dwellings where inspections may never be made.