O-pen devices, Overvolatge, IET-01, increasing the volatge to mitigate issues !!!!!

Question

Good morning all, I am looking for a bit of clarity - I have some fitted chargers which are tripping the O-pen device above 253 volts, this is down to spikes with the voltages on the DNO side. When contacting the DNO they are unable to rectify the issue as its within the tolerances that they work to. I have discussed this with the charger manufacturer who are stating that their charger voltages can be upped to 256 volts. The issue I have is that this charger is not fully compliant to IET -01 and I am struggling at present to fully understand the implications of IET -01 and its relationship with Bs7671, specifically the regulation stated below.

The one thing I am having some difficulty with is the impact of over voltages on our clients with their chargers constantly cutting off, and the fact that the DNOs will not help. I am struggling somewhat to fully interpret 722.411.4.1 (V) - in regards to how manufacturers of charge points can state the increase in volatges is acceptable, is this purely based on their methodolgy in regards to the stated regulation?

We have chargers from reputable British manufacturers with the ability to increase the voltage ranges, these manufacturers are stating that down to their interpretation of indent 5 that they can in fact do this, my issue is trying to understand if this is the case and could we implement these voltage increase, to help with the problem of tripping? Indent 5 does not specify voltage ranges, simply stating the same or greater protection as opposed to the other indents in this regulation? 
 
 I appreciate within Appendix 2 the voltages tolerances are stated as

Is it possible to work out with these tolerances if the methodology behind compliance with 722.411.4.1 (V) is met? 
 
 Thank you very much.

AJJewsbury · Accepted Answer

I suspect you're not going to get a nice yes/no answer for this - as there's no clear definition of what makes such a system safe or unsafe in the first place. As a bit of background there was a thread about the way open-pen devices like this work - Open PEN detection for 722.411.4.1 (iv) - as you seen there are situations where the results are perhaps less than ideal anyway. Increasing the acceptable voltage range will increasing the probability of the system remaining connected in a hazardous situation, but given the original system is not entirely perfect in the first place, whether that constitutes a significant reduction in safety is debatable rather than calculable. 
 I could see an argument that if the device had some additional mechanism for reducing the risk from shock under broken PEN conditions - not just voltage measuring, but say monitoring the c.p.c. current and disconnecting immediately if hazardous shock levels were present (say >10mA), and as that wasn't compromised at all by the voltage limit change, the overall risk might not be significantly increased. 
 - Andy.

Sergio Fernandez · Answer

Might be worth renting a CA PEL ( Chauvin Arnoux Power and Energy Logger) to collect some data as to the lows and highs. Other brand are available. I suspect as time goes on this will become more regular as sites change from Consumers to ProSumers. In the north of England people are stating that they are regularly getting 250 to 253v. This is probably why the EVSE ( Electric Vehicle Supply Equipment ) manufactured has the ability to tweak the tolerance to 256v. 
 
 Things will start to play different at 256v think about ADS ( Automatic Disconnection of Supply ) will it now become to sensative or not respond quick enough. This will probably need the IET, ENA (Energy Network Association) and EVSE industry for the UK to sit down and discuss this further.

Philip Oakley · Answer

I see that in New Zealand the have changed their supply voltage limits because of Prosumer issues from +6% to +10%, while keeping the DNO supply level at +6% to allow for back feeding from solar on longer distribution lines. 
 see https://www.youtube.com/watch?v=s8RXQERPzMY "The newly announced NZ Grid Voltage Increase explained". 
 This may give one view on how to explain things, even if it's not directly equivalent. 
 The other option is to distinguish between a "Fault" and "Disturbance" (aka Dangerous vs Annoying).

Dom · Answer

Thank you Graham, with the issue of renewable generation aside, we are seeing issues with the DNOs in that they are stating that the times they will allow over volatge are over certain time periods (meaning so many overvoltages within a set period would result in them stepping down the volatge). The issue here - with chargers that are not auto reset (so to speak) after an over volatge, means a client is resetting a charger multiple times a night. The DNOs are simply shutting off to our requests. 
 
 I think with the overall view points on this - the only option I have or will have is to look to install all equipment in accordance with IET -01 and where we have the issue of over voltage we will need to change equipment over. 
 
 Thank you very much for your reply.

lyledunn · Answer

Dom said; "Its one of these situations where we are damned if we do damned if we dont" 
 I imagine that may well have been the state of affairs that afflicted those who were responsible for the regulation, damned if they ignored the risk and damned if they insisted on control measures that would be difficult and costly to implement. Likely they saw a real risk with EVSE on PME supplies that deserved a specific regulation and strained to balance that with the disadvantages of any proffered control measures. Perhaps the cure would turn out worse than the illness. 
 That seems to be the issue here where the functionality of the EVSE is compromised by the o-pen control measure built into the EVSE by the manufacturer. 
 I can understand why manufacturers tried to make the solution integral with their equipment as the trade demands a plug and play arrangement. The trade does not want, and, perhaps because of demand, is not capable of providing sufficient numbers of skilled persons who are also capable of providing bespoke solutions to the vexed question of open PEN. If the roll out of EVSE provision is not to be impeded, that solution has to be packaged by the EVSE manufacturer. 
 If it turns out that the packaged solution is not fit for purpose then we have a serious problem. It seems that solar pv is expanding and that DNO networks may end up having voltage issues that cause EVSE to drop out, irrespective of the earthing arrangement the EVSE is connected to. Who knows, a doctor or critical care worker finding that their car was not charged because the network voltage slipped out of certain limits may be a greater risk than an open PEN event. 
 I have no idea of the state of the network in mainland UK. I am told that in most areas here in NI, the network is healthy and an open PEN condition, whilst not impossible, would be unlikely. Certainly, not more than a few miles from me on the other side of the border, in the ROI, the freshly expanded Part 722 of IS10101:2020 + A1 2024 (their equivalent of BS7671) expresses not one jot of concern about open PEN conditions, even though most of the network in the ROI is of a PME-type arrangement. 
 In other words, like the implementation of the hierarchy of risk control, get rid of the thing that is causing the problem, which might be the regulation itself.

O-pen devices, Overvolatge, IET-01, increasing the volatge to mitigate issues !!!!!

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