EV CHARGING EQUIPMENT

An interesting idea Chris, but one which would immediately become a political nightmare with many vested interests in making it mandatory and expensive. It is true that surgery may not always be the optimum solution for minor ailments, and death rates from dentistry are not zero for example. However decayed or broken teeth are both common and horrible, so we have widespread dentistry. In this case however the risk I have suggested, perhaps one death per year, and tens of millions of cars charged say 25 times a year on average, is an accident rate of 1 in 250 million. You are many times more likely to be killed outside your own gate by a road vehicle. A sense of proportion is necessary in all assessment of risk, the entire world in the UK thinks that risk assessments are the way to go, but when I do that the result is very safe yet we have section 722 and a COP, both of which are extremely cautious and suggest the risk is high (at least high enough to take a lot of measures and cost to remove; actually not remove but reduce by some small unknown amount). The risk of this accident is probably at a level of one thousandth of riding a bicycle on the road or perhaps even less. OK ban bicycles, they are far too dangerous to use, just imagine the pushback from that! The more this is discussed, the more it seems that the situation needs no special measures. I wonder how long it will take for someone to admit this and admit this is a non-problem? It is probably as likely as "someone" admitting that bicycles are a problem yet all drivers know this from direct experience!

Ok Richard, we all have a 13A socket with RCD protection. Extra cost zero. Charging point (OK it may be quicker but I could install another larger socket and the bit of electronics to charge quicker for a few quid) I will stick to £500 extra cost. Type Bs and lost neutral detection and a rod and install and everything costs at least that much at present. We are spending a Billion pounds a year (30 years life) no discount rate, so nearer 2 Billion in accounting terms, per life saved. Now explain the logic for this, as I asked, it is not a few extra quid, it is a huge sum much better spent on other things (perhaps even the NHS) where it would make a much bigger difference to lives saved or extended. Cost benefit is never used in safety discussions, so alleged "safety" is never costed.


Do not get the idea I am against safe working, or reasonable precautions because that is the opposite of my view. The electricity industry do live working all the time and it is more than adequately "safe". There is the odd incident but rarely any deaths to jointers, who are obviously well trained. The saving to everyone in money terms is huge, because cutting off areas from electricity has many downsides, while work is carried out. The same goes for some overhead line repairs where shutoffs tend to be even larger. Now consider the adequate word, how do you assess that? Clearly one has to decide that some accidents are acceptable, at a low level. Realistically it is never zero, as there is no way to do this except by locking everyone up, which also has a risk level (actually quite high). We should do the same with car charging. Every other country accepts a slight risk level, it appears that ours does not. Why not, that is the question we need to answer?

Dollar value on human life 

https://www.motherjones.com/politics/1977/09/pinto-madness/

Do an internet search for “Ford Pinto petrol tank” it is estimated that over 500 people were killed and many more maimed because Ford wanted to save a dollar.

https://www.autonews.com/article/20030616/SUB/306160770/lee-iacocca-s-pinto-a-fiery-failure

Dave, it's not the cost of a charging point you need to use in your calculation, but the overall increase in cost from whatever extra safety measures are being proposed against the number of lives those safety measures save. e.g. cost-benefit analysis on type B RCDs, lost neutral detection devices and install costs. I agree that for all but the most basic safety measures we're likely to conclude we should have spent that money on road safety or vaccines, etc. but £500 is clearly not the right number here.


The harder calculation is then the one of human nature. If you push the cost of a charging point install up to what extent will people decide they can't be bothered and daisy chain 3 extension leads out the window to a granny lead, complete with upturned buckets over all the sockets as we so often see on Christmas lights. Not that we see any significant increase in electrical deaths associated with Christmas lights so maybe that's not as dangerous as it sounds either.

For reasons which I completely fail to understand, some risks are treated in entirely different ways to others. In some areas a decision is made by "someone" (an entirely hidden person or body) that a risk must be avoided at all costs, often totally unreasonably large costs compared to the risk, say for arguments sake £1 billion per death, and in other cases that deaths on a small scale are acceptable. Here we are probably discussing the first case, whilst all other uses of the car follow the second case. If we changed to all electric cars it is likely there would be 30 million charging points around the country, some in services, most in peoples homes. Let us say that each costs on average £500. Thus we spend 15 billion pounds to save maybe 1 life a year. But we loose 1500 lives in cars from accidents for which we accept as a reasonable risk. There is something completely out of kilter here, and it is this worry about vehicle charging points and the possible risks, which are actually very small indeed. Perhaps someone, preferably the "someone" above, would care to make a reasonable logical case for this difference to me, and the public at large?

This is all explained in Annexes H and I of the 4th Edition of the EV CoP. Very briefly

I think I understand the thinking, but isn't this going way beyond BS 7671's requirements?


If my existing installation happened to be TT - than according to BS 7671 itself, can't I just connect up a charge point without any further consideration as far as earthing is concerned? Likewise if I had reliable TN-S (private transformer say) - even though the system's Earth reference could be tens or hundreds of metres from the EV parking space (which may or may not be influenced by some buried metalwork).


If PME voltages from buried services could be hazardous, shouldn't we have seen some incidents from other situations where a touch potential from several metres away could be simultaneously accessible - such as metal gates hung on metal posts or the tubular steel handrails often seen linking street to front door outside 'pensioner's bungalows'?


    - Andy.