[donald]

Unfortunately, that doesn't seem to be something that is going to be added, but I was just pondering the logic of protecting cars from PEN faults and such that have NEVER caused a recorded risk for someone charging their car, whereas falling space debris is a real and present danger that has actualised.

So, why PEN fault protection for car chargers, but no satellite debris protection?

In fact, why aren't all pedestrian walk-ways, in towns and across nature parks, now covered with a satellite-debris protection shield?

I'm just asking a stupid question about stupid HSE perspective. What makes a thing more of a risk; when it has actually happened, or when someone thinks it might?

 

[jmacneil]

Good to see you're back on form, @donald

 

[RoyOb]

Need to adjust your meds ?
But in all seriousness I'm sure there is someone doing the risk/cost analysis and making decisions what should be done to prevent deaths and how much it would cost vs benefit...

 

[farmergiles]

Unfortunately, that doesn't seem to be something that is going to be added, but I was just pondering the logic of protecting cars from PEN faults and such that have NEVER caused a recorded risk for someone charging their car, whereas falling space debris is a real and present danger that has actualised.

View attachment 163437



So, why PEN fault protection for car chargers, but no satellite debris protection?

In fact, why aren't all pedestrian walk-ways, in towns and across nature parks, now covered with a satellite-debris protection shield?

I'm just asking a stupid question about stupid HSE perspective. What makes a thing more of a risk; when it has actually happened, or when someone thinks it might?

Sod the chargers, what about the vehicle?
Don't fancy a Sputnik landing on my roof at 125mph.

 

[freddym]

Unfortunately, that doesn't seem to be something that is going to be added, but I was just pondering the logic of protecting cars from PEN faults and such that have NEVER caused a recorded risk for someone charging their car, whereas falling space debris is a real and present danger that has actualised.

View attachment 163437



So, why PEN fault protection for car chargers, but no satellite debris protection?

In fact, why aren't all pedestrian walk-ways, in towns and across nature parks, now covered with a satellite-debris protection shield?

I'm just asking a stupid question about stupid HSE perspective. What makes a thing more of a risk; when it has actually happened, or when someone thinks it might?

Are you OK. Not sleeping at night?

 

[Zebster]

Perhaps there haven't been any deaths from PEN faults because EVSE includes protection against this hazard? Similarly, if protection against satellite debris was commonly fitted to outdoor areas then this unlucky/lucky woman would have avoided this ordeal.

 

[RunningStrong]

PEN fault protection falls under the ALARP principle.

Sitting in your car is the ALARP solution to space debris.

 

[Gt6k]

I am glad its not just me that thinks PEN protection is rather overblown. If you do a proper search a PEN faults and PEN protection there is basically nothing that doesn't eventually trace back to press releases from a couple of PEN fault protection manufacturers.

 

[Jeremy Harris]

HSE stats for open PEN fault that cause injuries each year have been given before - go look them up, I can't be arsed to keep posting the blindingly obvious to people that insist on wearing blinkers.

 

[donald]

Perhaps there haven't been any deaths from PEN faults because EVSE includes protection against this hazard? Similarly, if protection against satellite debris was commonly fitted to outdoor areas then this unlucky/lucky woman would have avoided this ordeal.

That seems possible to me. If the star point of a 3 phase drifts too far then either it trips the EVSE into over-voltage, or if it is 'under-voltage' then surely that means it is EVSE charging on the other phases that is causing the current draw, so the folk on the lower-voltage phase are likely not charging a car? And indeed some EVSE have under-voltage protection too, but also the car's OBD itself will shut off if it is not getting an adequately high voltage through.

I think if one analyses PEN fault scenarios properly, one will see that the EVSE will trip on over-voltage wrt neutral, because that is the phase drawing the power to shift the star point wrt ground.

If all 3 phases are drawing equal power during a PEN fault then, with or without it, there is little chance of a hazard.

Plus charger cables are plastic not metal. What is the user going to grab first to stop the charge ... or in fact in most cases the charging will have already finished while they were asleep.

I also don't think all chargers have a direct connection to vehicle ground, but are resistively tied in parallel with a capacitor, for EMC reasons, so the EMC filtering will also help mitigate this fault.

I don't know all the specifics and I am not saying there is zero risk. I am saying while there is zero injury from this then there is a justified debate if, in actual fact, the existing measures without PEN detection is already 'as safe as reasonably practical'.

 

[Jeremy Harris]

The bottom line here is that there is absolutely nothing at all new about protecting from an open PEN fault. All non-Class II bits of kit outdoors have had to have open PEN fault protection for as long as I can remember - I was working on caravan sites in the late 1970's and every single hook up point had to have open PEN fault protection even back then. An EV is absolutely no different to a caravan hooked up to the mains, so unsurprisingly it needs the same protection.

 

[Simon..Hewison]

The bottom line here is that there is absolutely nothing at all new about protecting from an open PEN fault. All non-Class II bits of kit outdoors have had to have open PEN fault protection for as long as I can remember - I was working on caravan sites in the late 1970's and every single hook up point had to have open PEN fault protection even back then. An EV is absolutely no different to a caravan hooked up to the mains, so unsurprisingly it needs the same protection.

and still we have installers bypassing the pen fault detection requirement for outdoor installations by fitting the chargepoint electronics in a garage that is full of clutter, with the cable under the door to the car on the driveway.

 

[donald]

and still we have installers bypassing the pen fault detection requirement for outdoor installations by fitting the chargepoint electronics in a garage that is full of clutter, with the cable under the door to the car on the driveway.

If it is not disallowed by the regulations, then why not if there is no requirement?

You're sounding like HMRC there when they realised that 'their' rules that 'they' had decided on could be avoided by doing something else that 'they' allowed.

No-one's issue but the rule-setters if they bungle that sort of thing.

One sets rules so that people work 'with' them. To expect people work 'within the expectation of the author of the rules, irrespective of whether they said it or not, is assuming that mind-reading is a legal expectation.

To argue that the spirit of the rule should be complied with for safety's sake moves the responsibility of proving it is unsafe to the person making that claim. Are you making that claim, and what is your argument for it being unsafe?

 

[Jeremy Harris]

and still we have installers bypassing the pen fault detection requirement for outdoor installations by fitting the chargepoint electronics in a garage that is full of clutter, with the cable under the door to the car on the driveway.

The problem is largely one of skills fade, there are an awful lot of people trading as electricians that came from the period when there was little or no on-the-job training, when apprenticeships essentially didn't exist. This sort of stuff was passed on largely by more experienced apprenticemasters, who were familiar with the risk because back when we first moved to PME supplies it was a hot topic. Unless someone has worked in areas where these requirements are commonplace, like caravan sites, hot tub installations, installations in metal framed buildings, like greenhouses, then there is a good chance that the need to consider the risks from the loss of the PEN conductor won't be understood. There are an awful lot of electricians around that have only ever worked on domestic stuff, where they most probably haven't ever come across any non-Class II stuff being installed outdoors. Thankfully it seems that social media is now doing a pretty good job of replacing that partially lost understanding.

 

[Peirpoint]

In all fairness, if I was space junk I would do my best to hit someone dressed like that (someone dressed like that) especially if they were sneaking about at 3:30 AM.

Or is that FAKE NEWS as someone who might be back on Twitter used to squeal almost daily?

Gaz

 

[Anahata]

If all 3 phases are drawing equal power during a PEN fault then, with or without it, there is little chance of a hazard.

It's a big "if" for lives to depend on...
PEN fault protection is sometimes done by detecting abnormal line-neutral voltages. It's the worst method, allowing dangerously high voltages to be tolerated while also giving false positives.

Plus charger cables are plastic not metal. What is the user going to grab first to stop the charge ... or in fact in most cases the charging will have already finished while they were asleep.

The problem area is wider than that. Anyone touching the car for any reason is at risk, and the risk does not end when charging has stopped, because it's the earth wire that has gone live when there's a fault (hence the requirement that the protection device break all three llines.)

 

[donald]

It's a big "if" for lives to depend on...

No, it is the 'if' if it is not an over or under voltage.

IF this OR that. The different 'ifs' are .. different, was my only point.

The PEN fault alone is not the issue, it is possible you can have a PEN fault without any adverse outcome.

The issue is whether the phases are absorbing significantly differential current loads at the same time as a PEN fault, thus the neutral shifts away from ground with an apparent voltage appearing on it. But it does that due to differential loads which are NOT independent of what is going on on those phases, with EV charging being one of the larger loads on domestic 3 phase. If the neutral loses its tie with ground, the voltage will collapse on the phase charging (if the other two do not have EV charging going on) then the car will likely trip under-voltage. If there is EV charging going on on the other two phases but not yours then you will see a high voltage on neutral, but you're not charging so there's no direct connection from neutral to your car chassis even if it is still plugged in.

Most OBCs are neutral-chassis coupled via a resistor block and capacitor shunt, to act as a simple EMC filter whilst also tying the OBC bridge voltage to neutral. The capacitor is the low impedance short for high frequency content.

 

[Jeremy Harris]

The issue is whether the phases are absorbing significantly differential current loads at the same time as a PEN fault, thus the neutral shifts away from ground with an apparent voltage appearing on it. But it does that due to differential loads which are NOT independent of what is going on on those phases, with EV charging being one of the larger loads on domestic 3 phase. If the neutral loses its tie with ground, the voltage will collapse on the phase charging (if the other two do not have VE charging going on) an the car will likely trip. If there is EV charging going on on the other two phases but not yours then you will see a high voltage on neutral, but you're not charging so there's no direct connection from neutral to your car chassis even if it is still plugged in.

The highlighted test is false information.

The risk comes not from the neutral within the installation. The risk comes from the protective earth, which is always connected to the car body when the car is plugged in. The key is in the name of the incoming conductor that may fail open circuit, the PEN, Protective Earth and Neutral. PE is linked to N at the incoming supply - take a look at a PME/TN-C-S cut-out and this is obvious, the CPC will be connected to the neutral at the terminal adjacent to the main fuse. This means that the PE everywhere in the house will always be permanently connected to the supply neutral, so if there is any phase current imbalance, with the incoming neutral open circuit, then there will be a voltage above literal earth on the installation protective earth.

This doesn't matter inside the equipotential zone, simply because there is no literal earth available for someone to be in contact with. It matters outwith the equipotential zone, especially outdoors, because it's very likely that people will be in contact with the literal earth.

 

[Phil1]

@ JH

You're suggesting that there is a skills fade, surely skills only fade because people stopped bothering because it's very rarely, or hardly ever become an issue.

If it was such a major problem them it would be at the core principles of an electricians trade and teachings.

I personally do believe you when you say there is a risk there, but even with said HSE evidence you have provided before, I've not been convinced that there is any risk to the public whatsoever regarding open pen faults and these units.

It seems to be more a theoretical issue than one which we all need to be wary of. In fact something as simple as the coating of paint on the bodywork of the car may be enough to mitigate this risk. I've tried numerous times to strike a welding rod up on a painted surface and it simply doesn't work till you've scraped some off.

 

[Jeremy Harris]

@ JH

You're suggesting that there is a skills fade, surely skills only fade because people stopped bothering because it's very rarely, or hardly ever become an issue.

If it was such a major problem them it would be at the core principles of an electricians trade and teachings.

I personally do believe you when you say there is a risk there, but even with said HSE evidence you have provided before, I've not been convinced that there is any risk to the public whatsoever regarding open pen faults and these units.

It seems to be more a theoretical issue than one which we all need to be wary of. In fact something as simple as the coating of paint on the bodywork of the car may be enough to mitigate this risk. I've tried numerous times to strike a welding rod up on a painted surface and it simply doesn't work till you've scraped some off.

The issue is that we switched away from fitting non-Class II equipment in domestic installations. This was a deliberate move to reduce the risk of electric shock, so that pretty much everything used outdoors in a domestic setting now is Class II. A Class II bit of kit has no connection to the installation protective earth, instead it relies on double insulation to protect from shock, with no exposed, and potentially electrically connected in the event of a fault, conductive parts. Years ago this wasn't the case, power tools, electric garden tools, outdoor appliances, etc were all non-Class II, so there was an open PEN fault risk that was understood and mitigated for by the electricians doing the installation work.

That's the knowledge that has faded away, there are now a generation that have never known anything other than Class II stuff being used outdoors in a domestic setting, unlike their predecessors who knew all about this risk. We are now installing tens of thousands of supplies to non-Class II outdoor equipment and, rather unsurprisingly, the risk of an open PEN fault with this type of equipment was not widely appreciated, except for us older folks that were around long before we adopted double insulated equipment.