I wear electrostatic gloves as a basic precaution when I’m working on lower voltage 12v, 24v & 48v systems & yellow safety glasses (for protection against arc eye) which is often over looked on most videos I’ve seen on the subject.
Thank you for the information that there are scenarios in which the HV voltage does not switch off despite the interlock being disconnected! There will be many who do not know this and rely on the interlock! I myself am glad to have seen the video here today, you become more careful! A warning in the dashboard should be mandatory for the manufacturer! Keep up the good work :-)
I was suprized that the lockout did not kill the HV. It should not be possible to drive if all the HV cables are in place. The other assumption that worries me for first responders is that some cars will still drive with an isolation fault.
Really helpful.I would only work on my ev if I had done a high voltage course.but I noticed on my Peugeot that there is a removable tab under the bonnet that can be removed if you have an accident does that isolate all circuits I am worried that I might still have a live cut high voltage cable
did folk not fix valve radios that had 500Vs DC on the anodes of some valves. We seem to have forgotten that there were high voltage devices sitting on the shelf just to play music. They were quite happy to fix them themselves, 1A at 500V will kill just as fast as 200A. The main difference is how well you are cooked. 1A and you could be just medium rare. 🙂
Great video Gary. My Renault dealer removed the Battery maintenance isolator plug inside the car when they worked on our Zoe, I know this because the cover clips were broken when they returned it. Is it best practice to remove this (after car has shut down) when working on Zoes? and does it totally isolate the battery?
Hi, it does isolate the battery however extreme care must be taken as the socket contains full pack voltage so any slip or something falling in there would be extremely dangerous. I have a cover which goes over the socket made from the cover of a safety fuse. Basic safety training and ppe is essential tbh, basic courses are something like £300 and well worth it. Cheaper than dying. Cheers
Personally I would want a training course and have the correct PPE. That said I build power supplies for valve projects with well over 400v DC and had one that was 2.2Kv at 1amp. There the risk was more of RF burns. In the Zoe if I need to charge the 12v battery I ping the bonnet, leave it on the latch, put the key into a faraday pouch and leave it in the house. After about 15mins the HT is off and a quick check with a DMM shows it is safe to connect the charger. I could disconnect the HT battery by going through the flap in the floor but that is not necessary as nothing orange is ever touched.
You need to be extremely careful of the orange safety plug as there is full hv pack voltage in that socket as it disconnects positive and negative. Cheers
Yep it's not something you want to stick a meter left on the amps positions in... At minimum it's going to annihilate the meter, possibly one or both of your hands
DC voltage can lead to blood clots especially! dangerous😮! You could die 12h later and no one knows why/how to help you. I had a DC shock once at work from a small capacitor that was still charged, no one knows how much charge... It went into my index finger and out the back of my hand that was touching the casing of the inverter unit. It hurt like hell (very short). I had to undergo 24h supervision in a hospital because of the danger of a blood clot ❤❤
With the contractors open there shouldn't be any risk unless the battery itself is damaged or both contractors welded shut, isn't it? By removing 12V power the contactors will open no matter what.
A Zoe only has positive contactors, it had no negative contactor, so with one sticking contactor you can have high voltage present and in any case the high voltage system has capacitors so it can retain a dangerous voltage for a period after shutdown.
Coming from a railway background where safety is key (pun intended, the key to open the HV compartments must be placed in a special switch that drops the pantograph and shorts the HV at several points to ground) it was under my impression that removing the safety key (and/or opening both contactors) would both disconnect the battery AND short the rest of the system together, but it seems it wasn't designed this way. I wonder why.
@ thank you for the clarification. Just saw a video about the (undersized) Nissan Leaf contactors and assumed it was standard practice to have redundancy.
Could you link out the contractors and fuses and short the 400V Battery I would like to see if they would explode or just melt the cables It would also be better than the usual feeding the exhaust into the cabin with windows closed
This HV terminology is interesting because the electricity industry says LV is less than a 1000v AC or less than 1500v DC. And so to be classed as HV it needs to be greater than 1500v DC. I think the biggest thing with EVs is going to be thermal runaway. As you say you can't switch off a battery.
Yes the terms do vary but in vehicle terms hv is anything above 50v. It’s based on what could be dangerous to a person. It’s different if you’re working on the nations grid with hundreds of kv, in that situation your scale is different to ours 😆
@garycevrepairs used to do a lot of ups work, (uninterruptible power supplies) batteries are the most dangerous thing ever. You can't switch them off!!
in electronics hv is quite a meaningless term without context in cars hv is 350-800v , colour crt tvs the hv was 100-150vdc in valve radios the hv was 150-400v in solid state pa amps hv was plus + minus 50v -120v transistor class b/c hifi amps plus + minus 22v - 45v really just means dangerous voltage, at about 44v you start to get significant current through your skin which can cause heart arrhythmia but theres so many other variables that play into it , for example the 3 or 4 times i got shocked by 24,000 to 25,000vdc from one hand to the other and direct to earth ,yet i was fine just aching limbs and a high heart rate for a short while, theres one certain variable that meant that was not directly dangerous but not related at all to evs they are lethal waiting to happen!
Unfortunately, I think this is going to be another reason EV's are going to be more expensive to fix. Obviously there's the training and courses that the technicians have to go on, but then there's also the cost of the insurance from a business point of view. I'll bet it's substantially more expensive for a garage to get business insurance to work on EV's than it is normally. When you think of the extra liabilities such business owners would be exposed to, it makes me wonder how many small garages would even bother catering for these vehicles at the moment.
There are plenty of liabilities in servicing any car. Just different dangers. You can easily loose your fingers trying to mess with an ICE car. I have seen people with their hands in the engine bay while some one is trying to crank it.
because when fault finding you have to work with live circuits to take measurements /make tests , i for example have to work close to and around active airbags ,same reason. theres a popular myth on youtube that diagnostics tells you whats wrong, no ,90% it doesnt , it tells you where to look! for example most kit with most cars it cant even tell you a fuse is blown! think its only vw audi group that can tell you term 30 is missing to a module
i work on car electronics for a living and trust the french to ignore what interlock means! but then you are investigating/expecting faults so its foolish to expect sensible operation anyway! especially since so many faults these days are buggy software/corrupt firmare. so that one being renault means dacia and nissan are also dodgey then, do dacia have evs? not seen one
Your working on your electrics at home analogy is perhaps not the best. If anyone is planning to work on their electrics at home a circuit breaker wont save them from electrocution. You may have meant RCD but if you work live at home and touch the live and neutral you will still get electrocuted. You have to wonder why manufacturers have to use high voltage for anything other than the drive system. I think we all appreciate to get high power without high voltage means high current and so expensive and heavier cables but using high voltage on the ancillaries is questionable. I would be interested to see any alternative opinions but it does seem like cheaping out and then having to compromise on safety.
Interesting point. Some manufacturers monitor all the hv plugs from a central ecu so a dead ac compressor can still have its connections checked. That requires more wiring and central logic though.
@@garycevrepairs Higher voltage insulation on cables is cheaper than copper and plastic is always lighter than copper ! You have already got serial comms in a car so it shouldn't make a massive difference and the Zoe system, certainly in respect of the compressor, looks dangerous and stupid especially when they have already gone to the trouble of putting in an extra cable ! Sometimes these manufacturers have no joined up thinking. I see you say other manufacturers do similar things to Renault but Renault do have a track record of stupid ideas (usually to save money) which makes life harder or more costly for the customer at some point down the road (no pun intended). 😁
The problem with DC is there is no easy way of reducing the voltage like there is with a transformer for AC. you need a DC -DC converter which is just more to go wrong.
@@TheEmbeddedHobbyist DC to DC convertors have been around a long time, are well understood and are now everywhere - I studied them forty years ago when I took a degree in electrical engineering. Car companies do stupid things to save money - or they think it will save money. I worked for a multi national power electronics company as a project and design engineer but I am no longer in the industry so I may be out of touch but I suspect high voltage ancillaries are to save money - one way or another. The consequences of that will, as ever, be shifted elsewhere. 😒
Look at the official stats of how each year, more and more EV techs are dying. And the number of ICE techs are decreasing... yeah, high volts are dangerous.
I wear electrostatic gloves as a basic precaution when I’m working on lower voltage 12v, 24v & 48v systems & yellow safety glasses (for protection against arc eye) which is often over looked on most videos I’ve seen on the subject.
Thank you for the information that there are scenarios in which the HV voltage does not switch off despite the interlock being disconnected!
There will be many who do not know this and rely on the interlock!
I myself am glad to have seen the video here today, you become more careful!
A warning in the dashboard should be mandatory for the manufacturer!
Keep up the good work :-)
I was suprized that the lockout did not kill the HV. It should not be possible to drive if all the HV cables are in place.
The other assumption that worries me for first responders is that some cars will still drive with an isolation fault.
Really helpful.I would only work on my ev if I had done a high voltage course.but I noticed on my Peugeot that there is a removable tab under the bonnet that can be removed if you have an accident does that isolate all circuits I am worried that I might still have a live cut high voltage cable
did folk not fix valve radios that had 500Vs DC on the anodes of some valves.
We seem to have forgotten that there were high voltage devices sitting on the shelf just to play music.
They were quite happy to fix them themselves, 1A at 500V will kill just as fast as 200A. The main difference is how well you are cooked. 1A and you could be just medium rare. 🙂
Medium rare, tasty 🤔😁
Great video Gary. My Renault dealer removed the Battery maintenance isolator plug inside the car when they worked on our Zoe, I know this because the cover clips were broken when they returned it.
Is it best practice to remove this (after car has shut down) when working on Zoes? and does it totally isolate the battery?
Hi, it does isolate the battery however extreme care must be taken as the socket contains full pack voltage so any slip or something falling in there would be extremely dangerous. I have a cover which goes over the socket made from the cover of a safety fuse. Basic safety training and ppe is essential tbh, basic courses are something like £300 and well worth it. Cheaper than dying. Cheers
Useful info. Just remember not to stick your fingers (or metal objects) in 400V DC connectors.
I would always read the Haynes Manual first
Unfortunately Haynes do no produce manuals for EVs!
Personally I would want a training course and have the correct PPE. That said I build power supplies for valve projects with well over 400v DC and had one that was 2.2Kv at 1amp. There the risk was more of RF burns. In the Zoe if I need to charge the 12v battery I ping the bonnet, leave it on the latch, put the key into a faraday pouch and leave it in the house. After about 15mins the HT is off and a quick check with a DMM shows it is safe to connect the charger. I could disconnect the HT battery by going through the flap in the floor but that is not necessary as nothing orange is ever touched.
You need to be extremely careful of the orange safety plug as there is full hv pack voltage in that socket as it disconnects positive and negative. Cheers
Yep it's not something you want to stick a meter left on the amps positions in... At minimum it's going to annihilate the meter, possibly one or both of your hands
I always, without fail, watch ElectroBOOM`s YT channel before working on my ev. 😂
Haha, that guy has a phd, he knows how to get views 😆
DC voltage can lead to blood clots especially! dangerous😮!
You could die 12h later and no one knows why/how to help you.
I had a DC shock once at work from a small capacitor that was still charged, no one knows how much charge... It went into my index finger and out the back of my hand that was touching the casing of the inverter unit. It hurt like hell (very short).
I had to undergo 24h supervision in a hospital because of the danger of a blood clot ❤❤
@@MrKOenigma quite right and doesn't let go every half cycle like on ac
Wow glad you were ok!
With the contractors open there shouldn't be any risk unless the battery itself is damaged or both contractors welded shut, isn't it?
By removing 12V power the contactors will open no matter what.
A Zoe only has positive contactors, it had no negative contactor, so with one sticking contactor you can have high voltage present and in any case the high voltage system has capacitors so it can retain a dangerous voltage for a period after shutdown.
Coming from a railway background where safety is key (pun intended, the key to open the HV compartments must be placed in a special switch that drops the pantograph and shorts the HV at several points to ground) it was under my impression that removing the safety key (and/or opening both contactors) would both disconnect the battery AND short the rest of the system together, but it seems it wasn't designed this way. I wonder why.
@ thank you for the clarification. Just saw a video about the (undersized) Nissan Leaf contactors and assumed it was standard practice to have redundancy.
Could you link out the contractors and fuses and short the 400V Battery I would like to see if they would explode or just melt the cables It would also be better than the usual feeding the exhaust into the cabin with windows closed
Whilst that is an interesting thought I probably won’t give it a try…
So, is it enough to remove the battery fuse on the driver's side alone to cut off the high voltage?
This HV terminology is interesting because the electricity industry says LV is less than a 1000v AC or less than 1500v DC. And so to be classed as HV it needs to be greater than 1500v DC.
I think the biggest thing with EVs is going to be thermal runaway. As you say you can't switch off a battery.
Yes the terms do vary but in vehicle terms hv is anything above 50v. It’s based on what could be dangerous to a person. It’s different if you’re working on the nations grid with hundreds of kv, in that situation your scale is different to ours 😆
@garycevrepairs used to do a lot of ups work, (uninterruptible power supplies) batteries are the most dangerous thing ever. You can't switch them off!!
in electronics hv is quite a meaningless term without context
in cars hv is 350-800v ,
colour crt tvs the hv was 100-150vdc
in valve radios the hv was 150-400v
in solid state pa amps hv was plus + minus 50v -120v
transistor class b/c hifi amps plus + minus 22v - 45v
really just means dangerous voltage, at about 44v you start to get significant current through your skin which can cause heart arrhythmia
but theres so many other variables that play into it , for example the 3 or 4 times i got shocked by 24,000 to 25,000vdc from one hand to the other and direct to earth ,yet i was fine just aching limbs and a high heart rate for a short while, theres one certain variable that meant that was not directly dangerous but not related at all to evs they are lethal waiting to happen!
Very interesting!
Thanks !
@garycevrepairs just goes to show how you think you are safe, but 380 volts might be about to ruin your day.
Ruin your life I think!
Unfortunately, I think this is going to be another reason EV's are going to be more expensive to fix. Obviously there's the training and courses that the technicians have to go on, but then there's also the cost of the insurance from a business point of view. I'll bet it's substantially more expensive for a garage to get business insurance to work on EV's than it is normally. When you think of the extra liabilities such business owners would be exposed to, it makes me wonder how many small garages would even bother catering for these vehicles at the moment.
There are plenty of liabilities in servicing any car. Just different dangers.
You can easily loose your fingers trying to mess with an ICE car. I have seen people with their hands in the engine bay while some one is trying to crank it.
I wouldn't touch my ev just get someone reputable and who knows what they are doing to fix it
Why would you not use the hard unplug and isolation first before even going near anything live. I would not trust just the software lockout.
In a Zoe the isolator socket has full hv battery pack voltage…
because when fault finding you have to work with live circuits to take measurements /make tests , i for example have to work close to and around active airbags ,same reason. theres a popular myth on youtube that diagnostics tells you whats wrong, no ,90% it doesnt , it tells you where to look! for example most kit with most cars it cant even tell you a fuse is blown! think its only vw audi group that can tell you term 30 is missing to a module
If you touch an orange wire😱
You will fry
And cause a fire 👍
i work on car electronics for a living and trust the french to ignore what interlock means! but then you are investigating/expecting faults so its foolish to expect sensible operation anyway! especially since so many faults these days are buggy software/corrupt firmare. so that one being renault means dacia and nissan are also dodgey then, do dacia have evs? not seen one
Dacia Spring EV!
Has anyone been killed working on an EV 400VDC would be very painful and could cause your heart to stop
👁✌🤟🤘👍
oh i edited but i deleted 😞
I must test this 400v option
on AC Megane EV
Please don’t !
@@garycevrepairs 😇ok
Dont Panic🍎
Your working on your electrics at home analogy is perhaps not the best. If anyone is planning to work on their electrics at home a circuit breaker wont save them from electrocution. You may have meant RCD but if you work live at home and touch the live and neutral you will still get electrocuted.
You have to wonder why manufacturers have to use high voltage for anything other than the drive system. I think we all appreciate to get high power without high voltage means high current and so expensive and heavier cables but using high voltage on the ancillaries is questionable. I would be interested to see any alternative opinions but it does seem like cheaping out and then having to compromise on safety.
Interesting point. Some manufacturers monitor all the hv plugs from a central ecu so a dead ac compressor can still have its connections checked. That requires more wiring and central logic though.
@@garycevrepairs Higher voltage insulation on cables is cheaper than copper and plastic is always lighter than copper !
You have already got serial comms in a car so it shouldn't make a massive difference and the Zoe system, certainly in respect of the compressor, looks dangerous and stupid especially when they have already gone to the trouble of putting in an extra cable ! Sometimes these manufacturers have no joined up thinking.
I see you say other manufacturers do similar things to Renault but Renault do have a track record of stupid ideas (usually to save money) which makes life harder or more costly for the customer at some point down the road (no pun intended). 😁
The problem with DC is there is no easy way of reducing the voltage like there is with a transformer for AC. you need a DC -DC converter which is just more to go wrong.
@@TheEmbeddedHobbyist DC to DC convertors have been around a long time, are well understood and are now everywhere - I studied them forty years ago when I took a degree in electrical engineering. Car companies do stupid things to save money - or they think it will save money. I worked for a multi national power electronics company as a project and design engineer but I am no longer in the industry so I may be out of touch but I suspect high voltage ancillaries
are to save money - one way or another. The consequences of that will, as ever, be shifted elsewhere. 😒
@we-are-electric1445 they are but not simple as an ac transformer. My point was if you can run it off the hv then that's the cheapest way to do it.
Look at the official stats of how each year, more and more EV techs are dying. And the number of ICE techs are decreasing... yeah, high volts are dangerous.
Oh where do we find those kind of stats? Any reputable workshop should have suitable training/equipment.