I mentioned in another post that I would contact HSE regarding any issues reported to them arising from loss of neutral and EV charging points. They have responded and confirmed that there has been no incident reported to them. However, they were made aware of a small number of situations that were a result of poor or no load management. I should point out that this is HSE in Northern Ireland.
The Irish Regs (IS10101: 2020) on the other devote only 3/4 of a line; “In TN systems the final circuit supplying a connecting point shall be a TN-S system”. My understanding is that this regulation is not modified from HD 60364-722
Edit; maybe if GK reads this he could confirm or otherwise that last sentence.
Confirmed, although the Clause number is 722.312.2.1, and the requirement is
In a TN system, the final circuit supplying a connecting point shall be a TN-S system.
Interestingly, in IEC/HD speak, this does not mean the supply arrangement has to be TN-S; there are many international standards, which have the notion that in a TN-C-S, downstream of the point of separation of the protective conductor is TN-S.
As an aside, this creates a unique situation in interpreting those standards which are not incorporated in BS 7671 in the UK. For example, does BS EN 60079-14 permit the electrical installation in a hazardous area to be derived from a TN-C-S (PME) system?
I would also add that, whilst the UK is presently the only country whose national wiring standard is concerned with the risks of broken neutrals in TN-C-S supply distribution arrangements, other countries are beginning to consider them, as we have seen with the recent discussion thread here.
... and finally, I understand for the rest of the UK, we are looking at a recorded average of just under 1 broken neutral event reported today, but the YoY rate of increase is perhaps more concerning. I have not seen specific data regarding damage to equipment or installations, injuries, or worse, just "events".
The Irish Regs (IS10101: 2020) on the other devote only 3/4 of a line; “In TN systems the final circuit supplying a connecting point shall be a TN-S system”. My understanding is that this regulation is not modified from HD 60364-722
Edit; maybe if GK reads this he could confirm or otherwise that last sentence.
Confirmed, although the Clause number is 722.312.2.1, and the requirement is
In a TN system, the final circuit supplying a connecting point shall be a TN-S system.
Interestingly, in IEC/HD speak, this does not mean the supply arrangement has to be TN-S; there are many international standards, which have the notion that in a TN-C-S, downstream of the point of separation of the protective conductor is TN-S.
As an aside, this creates a unique situation in interpreting those standards which are not incorporated in BS 7671 in the UK. For example, does BS EN 60079-14 permit the electrical installation in a hazardous area to be derived from a TN-C-S (PME) system?
I would also add that, whilst the UK is presently the only country whose national wiring standard is concerned with the risks of broken neutrals in TN-C-S supply distribution arrangements, other countries are beginning to consider them, as we have seen with the recent discussion thread here.
... and finally, I understand for the rest of the UK, we are looking at a recorded average of just under 1 broken neutral event reported today, but the YoY rate of increase is perhaps more concerning. I have not seen specific data regarding damage to equipment or installations, injuries, or worse, just "events".
