Charging - can someone explain it?
Discussion
Right, I've asked my mate who's an electrical engineer to give me his stance on these 'granny' chargers. Here's his response;
"Using a 13A socket for EV charging is classed as Mode One. Which utilises a standardised socket outlet not exceeding 16A 250V AC which utilises the supply protective earth conductors under BS EN61851-1. Regarding DC leakage, you're looking at Type A RCD but that is not relevant for regulations until you hit 7kw."
He then goes on to add that anyone who is worried about plugging an EV into a UK socket should go and visit Europe or USA and then come back here, they wouldn't be worried at all...............
"Using a 13A socket for EV charging is classed as Mode One. Which utilises a standardised socket outlet not exceeding 16A 250V AC which utilises the supply protective earth conductors under BS EN61851-1. Regarding DC leakage, you're looking at Type A RCD but that is not relevant for regulations until you hit 7kw."
He then goes on to add that anyone who is worried about plugging an EV into a UK socket should go and visit Europe or USA and then come back here, they wouldn't be worried at all...............
audi321 said:
Right, I've asked my mate who's an electrical engineer to give me his stance on these 'granny' chargers. Here's his response;
"Using a 13A socket for EV charging is classed as Mode One. Which utilises a standardised socket outlet not exceeding 16A 250V AC which utilises the supply protective earth conductors under BS EN61851-1. Regarding DC leakage, you're looking at Type A RCD but that is not relevant for regulations until you hit 7kw."
He then goes on to add that anyone who is worried about plugging an EV into a UK socket should go and visit Europe or USA and then come back here, they wouldn't be worried at all...............
Comparing to the USA is pointless, we are in the UK and have much higher electrical safety standards. Furthermore, some European systems are pretty good."Using a 13A socket for EV charging is classed as Mode One. Which utilises a standardised socket outlet not exceeding 16A 250V AC which utilises the supply protective earth conductors under BS EN61851-1. Regarding DC leakage, you're looking at Type A RCD but that is not relevant for regulations until you hit 7kw."
He then goes on to add that anyone who is worried about plugging an EV into a UK socket should go and visit Europe or USA and then come back here, they wouldn't be worried at all...............
Your friend needs to reference why he considers the above to be correct. Particularly as we are talking Mode 2 here, not Mode 1 which do not communicate with the car (e.g. for scooters). I do not see any allowance under the Regulations to say the Regulations only apply at 7 KW. He has also stated the wrong type of RCD - it needs to be type B or type A with separate 6 mA DC leakage detection.
48k said:
Interesting discussion. As a non electrician - very educational. Question for the electricians - would it be reasonable to assume that the manufacturer supplied OEM granny charger that comes with the car meets the regulations or does the electric shock risk still exist? Given the regulations around type approval and construction and use regulations on car the itself - is it naïve to assume that any OEM kit provided with the car is of similar quality ?
For reference this is the consumer unit in my garage which is fed directly from the meter (not from the main house consumer unit). The EVSE charger on the outside garage wall is on the "EV" circuit, and I have two separate circuits for the garage sockets. So are people saying there is a risk of electric shock plugging the granny charger in to one of the sockets in the garage?
There is nothing wrong with the "Granny Chargers" provided, it's a question of whether they can be used with any 3 pin socket or whether the 3-pin socket should have the same safety measures in place that you would have on a "proper" charger installation (Mode 3). That is, the "Granny Chager" can be safe, but only if used with x, y and z. I don't think this has been settled in this thread and would need a proper read of 18th ed and amendments.For reference this is the consumer unit in my garage which is fed directly from the meter (not from the main house consumer unit). The EVSE charger on the outside garage wall is on the "EV" circuit, and I have two separate circuits for the garage sockets. So are people saying there is a risk of electric shock plugging the granny charger in to one of the sockets in the garage?
You can't really tell from that and it also depends on the installation date, type A RCDs were previously allowed until the issue around DC leakage was properly understood, and it is not clear how your garage is earthed and whether any other metallic objects in the building are earthed using a different system.
pghstochaj said:
audi321 said:
Right, I've asked my mate who's an electrical engineer to give me his stance on these 'granny' chargers. Here's his response;
"Using a 13A socket for EV charging is classed as Mode One. Which utilises a standardised socket outlet not exceeding 16A 250V AC which utilises the supply protective earth conductors under BS EN61851-1. Regarding DC leakage, you're looking at Type A RCD but that is not relevant for regulations until you hit 7kw."
He then goes on to add that anyone who is worried about plugging an EV into a UK socket should go and visit Europe or USA and then come back here, they wouldn't be worried at all...............
Comparing to the USA is pointless, we are in the UK and have much higher electrical safety standards. Furthermore, some European systems are pretty good."Using a 13A socket for EV charging is classed as Mode One. Which utilises a standardised socket outlet not exceeding 16A 250V AC which utilises the supply protective earth conductors under BS EN61851-1. Regarding DC leakage, you're looking at Type A RCD but that is not relevant for regulations until you hit 7kw."
He then goes on to add that anyone who is worried about plugging an EV into a UK socket should go and visit Europe or USA and then come back here, they wouldn't be worried at all...............
Your friend needs to reference why he considers the above to be correct. Particularly as we are talking Mode 2 here, not Mode 1 which do not communicate with the car (e.g. for scooters). I do not see any allowance under the Regulations to say the Regulations only apply at 7 KW. He has also stated the wrong type of RCD - it needs to be type B or type A with separate 6 mA DC leakage detection.
The other important thing about granny chargers is that they usually pull 10A max. The fuse will be 13A. You won't get 16A or 3.3kW, you will get about 2.4kW.
You should always plug directly into the socket too, don't use an extension lead. The granny charger (EVSE) has a temperature sensor in the plug that causes is to stop drawing power if it overheats. Using an extension lead defeats that.
For long term use I'd say always get a charger, even if it's only 3.3kW. As well as being faster it will be slightly safer. But if you are getting one installed then in most cases the cost to get a 7kW one won't be much more.
pghstochaj said:
audi321 said:
Right, I've asked my mate who's an electrical engineer to give me his stance on these 'granny' chargers. Here's his response;
"Using a 13A socket for EV charging is classed as Mode One. Which utilises a standardised socket outlet not exceeding 16A 250V AC which utilises the supply protective earth conductors under BS EN61851-1. Regarding DC leakage, you're looking at Type A RCD but that is not relevant for regulations until you hit 7kw."
He then goes on to add that anyone who is worried about plugging an EV into a UK socket should go and visit Europe or USA and then come back here, they wouldn't be worried at all...............
Your friend needs to reference why he considers the above to be correct. Particularly as we are talking Mode 2 here, not Mode 1 which do not communicate with the car (e.g. for scooters)."Using a 13A socket for EV charging is classed as Mode One. Which utilises a standardised socket outlet not exceeding 16A 250V AC which utilises the supply protective earth conductors under BS EN61851-1. Regarding DC leakage, you're looking at Type A RCD but that is not relevant for regulations until you hit 7kw."
He then goes on to add that anyone who is worried about plugging an EV into a UK socket should go and visit Europe or USA and then come back here, they wouldn't be worried at all...............
ETA - just text him again and he's certain it's Mode 1. Mode 2 when connecting to a dedicated supply.
Edited by audi321 on Monday 29th November 16:29
audi321 said:
pghstochaj said:
audi321 said:
Right, I've asked my mate who's an electrical engineer to give me his stance on these 'granny' chargers. Here's his response;
"Using a 13A socket for EV charging is classed as Mode One. Which utilises a standardised socket outlet not exceeding 16A 250V AC which utilises the supply protective earth conductors under BS EN61851-1. Regarding DC leakage, you're looking at Type A RCD but that is not relevant for regulations until you hit 7kw."
He then goes on to add that anyone who is worried about plugging an EV into a UK socket should go and visit Europe or USA and then come back here, they wouldn't be worried at all...............
Your friend needs to reference why he considers the above to be correct. Particularly as we are talking Mode 2 here, not Mode 1 which do not communicate with the car (e.g. for scooters)."Using a 13A socket for EV charging is classed as Mode One. Which utilises a standardised socket outlet not exceeding 16A 250V AC which utilises the supply protective earth conductors under BS EN61851-1. Regarding DC leakage, you're looking at Type A RCD but that is not relevant for regulations until you hit 7kw."
He then goes on to add that anyone who is worried about plugging an EV into a UK socket should go and visit Europe or USA and then come back here, they wouldn't be worried at all...............
Edited by audi321 on Monday 29th November 16:24
The link I provided in an earlier page suggests I am not the only person to believe that "Granny Chargers" are not being used in compliance with the Regulations.
audi321 said:
ETA - just text him again and he's certain it's Mode 1. Mode 2 when connecting to a dedicated supply.
Explanation of each mode:Edited by audi321 on Monday 29th November 16:29
https://www.dazetechnology.com/charging-modes-for-...
or here if you don't believe the first resource:
https://thedriven.io/2018/08/28/faq9-ev-charging-s...
"Granny Chargers" are Mode 2 for all intents and purposes of this discussion (i.e. current EVs), I don't think any modern EV uses Mode 1.
pghstochaj said:
audi321 said:
ETA - just text him again and he's certain it's Mode 1. Mode 2 when connecting to a dedicated supply.
Explanation of each mode:Edited by audi321 on Monday 29th November 16:29
https://www.dazetechnology.com/charging-modes-for-...
or here if you don't believe the first resource:
https://thedriven.io/2018/08/28/faq9-ev-charging-s...
"Granny Chargers" are Mode 2 for all intents and purposes of this discussion (i.e. current EVs), I don't think any modern EV uses Mode 1.
pghstochaj said:
...
No, I am a process engineer and project manage the construction of power stations. The knowledge I have is from having a Podpoint charger installed, by reading BS 7671 and having to arrange some commercial chargers to be installed as part of enabling works on my current project. Therefore, I have a basic working knowledge but would need to read BS 7671 18th Ed and its amendments to understand whether the safety regulations relevant to Mode 3 chargers apply to Mode 2 chargers or not. The word "charger" used loosely here (whether Mode 2 or 3).
The link I provided in an earlier page suggests I am not the only person to believe that "Granny Chargers" are not being used in compliance with the Regulations.
I agree. I am not an electrician either, but am an Electronics Design Engineer - presently doing some background work on EVSE and EVSE testing.No, I am a process engineer and project manage the construction of power stations. The knowledge I have is from having a Podpoint charger installed, by reading BS 7671 and having to arrange some commercial chargers to be installed as part of enabling works on my current project. Therefore, I have a basic working knowledge but would need to read BS 7671 18th Ed and its amendments to understand whether the safety regulations relevant to Mode 3 chargers apply to Mode 2 chargers or not. The word "charger" used loosely here (whether Mode 2 or 3).
The link I provided in an earlier page suggests I am not the only person to believe that "Granny Chargers" are not being used in compliance with the Regulations.
Reference below as to what Ohme say in relation to their plug-in charging lead as mentioned previously.
https://ohme.odoo.com/document/download/48/ef1eab8...
pghstochaj said:
48k said:
Interesting discussion. As a non electrician - very educational. Question for the electricians - would it be reasonable to assume that the manufacturer supplied OEM granny charger that comes with the car meets the regulations or does the electric shock risk still exist? Given the regulations around type approval and construction and use regulations on car the itself - is it naïve to assume that any OEM kit provided with the car is of similar quality ?
For reference this is the consumer unit in my garage which is fed directly from the meter (not from the main house consumer unit). The EVSE charger on the outside garage wall is on the "EV" circuit, and I have two separate circuits for the garage sockets. So are people saying there is a risk of electric shock plugging the granny charger in to one of the sockets in the garage?
There is nothing wrong with the "Granny Chargers" provided, it's a question of whether they can be used with any 3 pin socket or whether the 3-pin socket should have the same safety measures in place that you would have on a "proper" charger installation (Mode 3). That is, the "Granny Chager" can be safe, but only if used with x, y and z. I don't think this has been settled in this thread and would need a proper read of 18th ed and amendments.For reference this is the consumer unit in my garage which is fed directly from the meter (not from the main house consumer unit). The EVSE charger on the outside garage wall is on the "EV" circuit, and I have two separate circuits for the garage sockets. So are people saying there is a risk of electric shock plugging the granny charger in to one of the sockets in the garage?
You can't really tell from that and it also depends on the installation date, type A RCDs were previously allowed until the issue around DC leakage was properly understood, and it is not clear how your garage is earthed and whether any other metallic objects in the building are earthed using a different system.
48k said:
Thanks. It was installed last month, the earth goes back to the meter (there's an armoured cable running from the garage in to the meter cupboard) with a new isolator that was installed in the meter cupboard). Not asking you to diagnose anything from photos on the internet but this thread has been very eye opening. I would never have thought there might be a risk of electric shock touching the car if it is connected to the granny charger.
Looks a reasonable CU. Nice that it has Surge Protection.The only question I would raise is why a 32A RCBO? To supply an EV with a 32A charge current, you would normally rate the breaker higher than that. Typically 40A - this assumes that the cable being protected is also rated at 40A+
The earthing, being PME, I feel is up for debate.
Some installers/manufacturers claim you don't need an earth rod. Some EVSE do monitoring of voltages on live, neutral and earth coupled to a 3 pole isolator (that cuts the earth connection too). However, it is my understanding that all thse devices do actually need an earth reference - which in reality means an earth rod - just maybe not one capable of sinking the entire fault current.
PH probably isn't the place to go in to the finer points of earthing and open PEN problems - a good link below for those interested.
https://electrical.theiet.org/wiring-matters/years...
Difficult to judge how likely it is to actually cause a problem that bites you.
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