EV tripping Earth Leakage Breaker ?

[so called]

So sold my BMW i3S and bought a Hyundai Ioniq 5 last week.
Came to charge it on my home 7kW charger yesterday evening and after a few minutes, it tripped the ELB.

There Washer and dryer were also on at the time so eliminated them one at a time to the Car.
I can't see how the car itself would have / need an earth in the lead so think it's down to the charger.
Having said that, there were no problems with the i3.

As a test, I'll disconnect the Earth at the charger.

Anyone else had this issue?

[so called]

Just to add, tried it with my 3kW charger this morning and it tripped the ELCB straight away.

[LordFlathead]

I would contact your dealer immediately. Had a few nuisance trips when I owned a Zoe but nothing like this. If you've tried both charging methods and get the same, then the problem is with the car.

[so called]

Yes, I called the Dealer this morning after trying the granny charger.
They first responded was, "It passed it's inspection and no problem charging it here".
They've agreed that it needs looking at and will call me shortly.

[anonymous-user]

Because the BMW has a carbon tub is has a particularly low earth leakage and capacitive coupling to ground. There may be nothing wrong persay with the 5, perhaps your ELB has aged and is tripping at a lower current than it should.

An easy test is to introduce a deliberate earth leakage of a known current from live to earth and see if it trips. Your electrician should be able to do this


(240Vrms and a 24k resistor should leak 10 mA to earth, which generally shouldn't trip the ELB)

[NS66]

What wall charger is it?

Mine was doing the same and found the RCBO burnt out - about to replace with a new updated version.

[No ideas for a name]

so called said:

....
I can't see how the car itself would have / need an earth in the lead so think it's down to the charger.

The earth is necessary, and *is* in the lead. It is the centre pin on a type 2 connector labeled PE.
It is the reference for the PP and CP signals.

[so called]

Great, thanks for the detailed replies.
I just a PodPoint at the local Tesco and it was fine. I’ve then tried the 13 amp charger at my sons house so looks like my house.

Many years ago I was told that an ELCB should be replaced after a number of trip operations so looks like that advice was correct.

We have BG Home Care so I’ll call them.

Glad I didn’t disconnect the earth !!!

Again, thanks for the great advice.

[anonymous-user]

No ideas for a name said:

so called said:

....
I can't see how the car itself would have / need an earth in the lead so think it's down to the charger.

The earth is necessary, and *is* in the lead. It is the centre pin on a type 2 connector labeled PE.
It is the reference for the PP and CP signals.

Your cars metal body is "earthed" to prevent a short in the OnBoardCharger from accidentally driving that body to mains voltage should the live wire contact the chassis metal work (The metal body of the OBC is connected to the chassis for safety, and an internal failure could make this occur (L to E). This is entirely on the AC side of the charger, ie the feed from your mains, as the EVs battery itself is galvanically isolated from the chassis, so earthing the chassis has no effect on that DC side of the system.

It's the same reason charge points now need to have an earth rod or specific "loss of earth" detection. The irony being that in this case, where a loss of neutral and earth in your mains feed from the grid, all the metal things in your house are now live (taps, toaster, radiators etc) and yet we don't have to have a house earth rod........... It's actually really quite hard to touch an unpainted or un-insulated bit of metal on a modern car btw, as due to the requirements for corrsion resistance, pretty much everything is painted or anodised etc

[SWoll]

Good news. Can only imagine the fun you'd have had if it was the car that was faulty..

[ruggedscotty]

Max_Torque said:

Because the BMW has a carbon tub is has a particularly low earth leakage and capacitive coupling to ground. There may be nothing wrong persay with the 5, perhaps your ELB has aged and is tripping at a lower current than it should.

An easy test is to introduce a deliberate earth leakage of a known current from live to earth and see if it trips. Your electrician should be able to do this


(240Vrms and a 24k resistor should leak 10 mA to earth, which generally shouldn't trip the ELB)

Nope and why you should be careful of taking electrical advice on a forum. If there is an issue and you put a resistor from live to earth you will raise the potential of what that resistor connects to and could injure others... so no.

Get an electrician in. someone that actually knows electrics and has the appropriate test kit.

You need to check your supply and then carry out trip tests on the RCD with a proper apparatus to find out if the residual current trip is correct.

An earth fault can be the hardest to find.

[ruggedscotty]

Max_Torque said:

No ideas for a name said:

so called said:

....
I can't see how the car itself would have / need an earth in the lead so think it's down to the charger.

The earth is necessary, and *is* in the lead. It is the centre pin on a type 2 connector labeled PE.
It is the reference for the PP and CP signals.

Your cars metal body is "earthed" to prevent a short in the OnBoardCharger from accidentally driving that body to mains voltage should the live wire contact the chassis metal work (The metal body of the OBC is connected to the chassis for safety, and an internal failure could make this occur (L to E). This is entirely on the AC side of the charger, ie the feed from your mains, as the EVs battery itself is galvanically isolated from the chassis, so earthing the chassis has no effect on that DC side of the system.

It's the same reason charge points now need to have an earth rod or specific "loss of earth" detection. The irony being that in this case, where a loss of neutral and earth in your mains feed from the grid, all the metal things in your house are now live (taps, toaster, radiators etc) and yet we don't have to have a house earth rod........... It's actually really quite hard to touch an unpainted or un-insulated bit of metal on a modern car btw, as due to the requirements for corrsion resistance, pretty much everything is painted or anodised etc

The electrical supplies to a domestic house is categorised according to the way that it is furnished to you.

Basically in a single phase supply you have a live and a neutral connection. Both of them carry current and you have a voltage across the live and the neutral. Now the safety connection - this is the earth, and actually this is the neutral. The earth connects to the neutral and provides a way for any leak to get back to the neutral if any part of the installation becomes live by accident. through the earth. This can be either through the earthed metal work, or actually through the real earth. Before ELCB and RCB's we were only proteced by fuses and you have to have a fair chunk of current to blow a fuse.

A 32A fuse... thats rated to 32,000mA. your usual domestic RCD is rated at 30mA. And it works differently to a fuse or a circuit breaker. those devices are looking for an overload, a current in excess of the rating. like what would happen with a short circuit. with an RCD its looking for an imbalance. so what it sees going out the live must come back on the neutral. if that differs by more than 0.03A or 30mA then pop it disconnects the supply.

Going back to the electrical supply.

T = terra or Ground

N = neutral


Now some supplies have a desigantion of TN-C-S, (PME) this means that the terra ground is combined with the neutral to the house and then seperates. This is at the board cable termination before the meter in your house.they connect the earth to the neutral and bring that out to the earth terminal.

Now this is what causes the issue - if the neutral to the house becomes damaged you still have the power on the live. Nothing would be working as the neutral was broken... but there is 240v right there... and if you have items connected in the house that voltage would be on the neutral as the power would pass through the equipment. That neutral not connected to anything would mean that 240v would be on the neutral. And as the earth is derived from the neutral at the board connection. It brings danger to the unsuspecting. All that is earthed to the earth terminal would infact be live. And if you were standing on the ground and touched anything earthed you would recieve a shock.

This is why EV chargers require special protection to ensure that this type of fault is detected and the supply is tripped. Due to the nature of the issue with the neutral and earth connection they use a seperate earthing rod for the EV charger

You might find that you need to check your supply and ensure that all is well with the installation. This is why getting in a spark would be advisable, someone that can run loop impedance checks and ensure that there is no issue there, and also test your rcd / elcb.

https://hager.com/uk/get-involved/news-and-press/e...

https://static1.squarespace.com/static/5b96995789c...

[LordFlathead]

As above this is correct. Live and neutral either bonded at sub station or locally depending the installation type.

If in doubt seek professional advice from the DNO or a qualified sparky and ignore that idiot salesperson that needs reporting.

[ruggedscotty]

the drawing - As said get it checked....

[so called]

Again, thanks for the very detailed responses and safety warnings from you knowledgeable PH folk.

A lot of very interesting details such as the difference between the BMW carbon fibre compared to the Ioniq 5 steel.
Local Tesco has a 50kW charger so did a slow shop last night and charged it to 100% at the same time.

It was a little amusing earlier yesterday passing all the cars lining up for fuel at Tesco’s and then me having to go back in the evening for my ‘fuel’.
Still, I topped up with 20kWh and it only charged me 9 pence.

I’ll be making a call Monday for someone to come out.
Many thanks.

[anonymous-user]

ruggedscotty said:

Max_Torque said:

No ideas for a name said:

so called said:

....
I can't see how the car itself would have / need an earth in the lead so think it's down to the charger.

The earth is necessary, and *is* in the lead. It is the centre pin on a type 2 connector labeled PE.
It is the reference for the PP and CP signals.

Your cars metal body is "earthed" to prevent a short in the OnBoardCharger from accidentally driving that body to mains voltage should the live wire contact the chassis metal work (The metal body of the OBC is connected to the chassis for safety, and an internal failure could make this occur (L to E). This is entirely on the AC side of the charger, ie the feed from your mains, as the EVs battery itself is galvanically isolated from the chassis, so earthing the chassis has no effect on that DC side of the system.

It's the same reason charge points now need to have an earth rod or specific "loss of earth" detection. The irony being that in this case, where a loss of neutral and earth in your mains feed from the grid, all the metal things in your house are now live (taps, toaster, radiators etc) and yet we don't have to have a house earth rod........... It's actually really quite hard to touch an unpainted or un-insulated bit of metal on a modern car btw, as due to the requirements for corrsion resistance, pretty much everything is painted or anodised etc

The electrical supplies to a domestic house is categorised according to the way that it is furnished to you.

Basically in a single phase supply you have a live and a neutral connection. Both of them carry current and you have a voltage across the live and the neutral. Now the safety connection - this is the earth, and actually this is the neutral. The earth connects to the neutral and provides a way for any leak to get back to the neutral if any part of the installation becomes live by accident. through the earth. This can be either through the earthed metal work, or actually through the real earth. Before ELCB and RCB's we were only proteced by fuses and you have to have a fair chunk of current to blow a fuse.

A 32A fuse... thats rated to 32,000mA. your usual domestic RCD is rated at 30mA. And it works differently to a fuse or a circuit breaker. those devices are looking for an overload, a current in excess of the rating. like what would happen with a short circuit. with an RCD its looking for an imbalance. so what it sees going out the live must come back on the neutral. if that differs by more than 0.03A or 30mA then pop it disconnects the supply.

Going back to the electrical supply.

T = terra or Ground

N = neutral


Now some supplies have a desigantion of TN-C-S, (PME) this means that the terra ground is combined with the neutral to the house and then seperates. This is at the board cable termination before the meter in your house.they connect the earth to the neutral and bring that out to the earth terminal.

Now this is what causes the issue - if the neutral to the house becomes damaged you still have the power on the live. Nothing would be working as the neutral was broken... but there is 240v right there... and if you have items connected in the house that voltage would be on the neutral as the power would pass through the equipment. That neutral not connected to anything would mean that 240v would be on the neutral. And as the earth is derived from the neutral at the board connection. It brings danger to the unsuspecting. All that is earthed to the earth terminal would infact be live. And if you were standing on the ground and touched anything earthed you would recieve a shock.

This is why EV chargers require special protection to ensure that this type of fault is detected and the supply is tripped. Due to the nature of the issue with the neutral and earth connection they use a seperate earthing rod for the EV charger

You might find that you need to check your supply and ensure that all is well with the installation. This is why getting in a spark would be advisable, someone that can run loop impedance checks and ensure that there is no issue there, and also test your rcd / elcb.

https://hager.com/uk/get-involved/news-and-press/e...

https://static1.squarespace.com/static/5b96995789c...

all good and true, but fails to explain why we legally need an earth rod for our EVs but not for our houses if the loss of return is such a big issue?

I'm going to suggest it's simply a handy mechanism to bundle some "oh,you must get that installed by a specialist" into our expensive lives.....





(BTW, i design EV's and EVSE's for a living :-)

[so called]

Well chaps, fitted a new ELCB this morning.
Charger went through it's start up sequence after power back on.
Plugged into car charge point and after a few moments, trip, ELCB off again

Maybe something else is leaking and the charger takes it over the edge?

I've tried it at my sons house and charges fine.
Charged it to 100% at a Tesco PodPoint.

[No ideas for a name]

so called said:

Well chaps, fitted a new ELCB this morning.
Charger went through it's start up sequence after power back on.
Plugged into car charge point and after a few moments, trip, ELCB off again

Maybe something else is leaking and the charger takes it over the edge?

I've tried it at my sons house and charges fine.
Charged it to 100% at a Tesco PodPoint.

Do you have a ELCB that trips the whole house (or some circuits on a split load board)? Or is that breaker only supplying the EVSE?
I am guessing it is the former, so as you say existing leakage is 'adding up'.

In which case, open the breakers for all other circuits, and retest with only the EVSE in use.
I know, it isn't a 100% test as the breakers are likey to be single pole so the neutral circuits are still connected.

[finlo]

I think you'll find ELCB's were superseded in the 70's!

[so called]

No ideas for a name said:

so called said:

Well chaps, fitted a new ELCB this morning.
Charger went through it's start up sequence after power back on.
Plugged into car charge point and after a few moments, trip, ELCB off again

Maybe something else is leaking and the charger takes it over the edge?

I've tried it at my sons house and charges fine.
Charged it to 100% at a Tesco PodPoint.

Do you have a ELCB that trips the whole house (or some circuits on a split load board)? Or is that breaker only supplying the EVSE?
I am guessing it is the former, so as you say existing leakage is 'adding up'.

In which case, open the breakers for all other circuits, and retest with only the EVSE in use.
I know, it isn't a 100% test as the breakers are likey to be single pole so the neutral circuits are still connected.

Yes, covers the whole house.
I’ve always called them ELCB’s, it’s an age thing.
I’ll try shutting off other circuits but I’ll get someone out tomorrow.