UK domestic socket charging

[Montego]

Possibly but there's no doubt that a proper evse charger is safer and certainly more convenient if you need a fast or full charge.. plus there's the advantage or a cheaper off peak tariff but I;m not sure whether you would qualify with a Rolec and an MG4, do you know?

Key word is "if". For routine charging I don't need a fast charger. If I do, it's not too far to go. As observed above, the cost of the charger is difficult to justify in terms of tariff reduction. In fact I have never found an off peak tariff that is worthwhile in terms of the flexibility lost. On those dual tariffs the peak charge tends to be higher than I normally pay. So the estimated annual cost is not that different.
Had I realised, before I ordered the charger, that the car manufacturer and charger manufacturer would restrict my choice of tariff I might have thought twice about the charger selection, but I purchased what I thought was best value at the time, and have been very satisfied with it (see Why Pod Point users love their home charger). But, still think the granny lead is the best option for home charging in my case.

 

[Buster72]

I have only ever charged using the MG supplied granny charger. I do it from 12.00 to 5.00 am with the British Gas EV tariff. And I have never had any problems. Easily the cheapest way to charge an EV. Just like charging a phone.

 

[bedsev]

I have only ever charged using the MG supplied granny charger. I do it from 12.00 to 5.00 am with the British Gas EV tariff. And I have never had any problems. Easily the cheapest way to charge an EV. Just like charging a phone.

Do you have a an EV certified plug socket or a dedicated circuit, or do you just plug it in a regular plug socket?

 

[mikgle]

OK I have received and installed the Masterplug EV charging socket from Halfords. It replaced an existing BG (same make actually) Storm double socket under my carport. A bit bulkier but a doddle to fit.
It comes with a 16A type A rcbo which strictly speaking not necessary as I have a similar rcbo fitted but handy if you haven't..
Attached some pics,

OK I have received and installed the Masterplug EV charging socket from Halfords. It replaced an existing BG (same make actually) Storm double socket under my carport. A bit bulkier but a doddle to fit.
It comes with a 16A type A rcbo which strictly speaking not necessary as I have a similar rcbo fitted but handy if you haven't..
Attached some pics,

I like the fact that there's no switch on the socket, always a weak point with sockets and will add to the resistance/warming of it under load.

 

[DixieTGS]

It comes with a 16A type A rcbo which strictly speaking not necessary as I have a similar rcbo fitted but handy if you haven't.

I don't know if it's a problem which only affects older RCBOs but if you have an RCBO in the garage that is supplied from an RCBO in the consumer unit it can cause issues.

In my case when the consumer unit was replaced with one containing RCBOs, half the house could trip out each time the Off/Test button was pressed in the garage.

I'm wondering if garage devices have a much quicker trip time than the consumer unit ones nowadays?

 

[mikgle]

I don't know if it's a problem which only affects older RCBOs but if you have an RCBO in the garage that is supplied from an RCBO in the consumer unit it can cause issues.

In my case when the consumer unit was replaced with one containing RCBOs, half the house could trip out each time the Off/Test button was pressed in the garage.

I'm wondering if garage devices have a much quicker trip time than the consumer unit ones nowadays?

No they all should be 30mA and trip within 300mS at that level, 50mS for 5x 30mA. Its just random, not dangerous but ad you say could be inconvenient if your whole house is on one RCD.. some installations may have a 100mA delayed action RCD thus preventing it tripping first.

 

[JAD]

I'm coming up to a year's charging almost exclusively via the MG provided granny charger. Mostly overnight charges in my garage, usually at 1.9kw. Being retired and have the use of another car, I'm lucky that I can plan charges. I usually charge 20-80% as recommended by MG. No issues whatsoever.

 

[Atworth196]

There is a lot of discussion on various youtube sites (eg efixx) ref ev charging using a 3 pin granny lead i.e.should you do it? is it dangerous? etc. I wonder how many of you use this method, either occasionally or even all the time? I am an electrician and can see both sides of the argument.

For information, you can buy (eg Halfords) an ev charging socket for the purpose, price £49.95 Is anybody using one of these? I would be interested in how they find it.. Many thanks.

I have used a granny charger for 3 years with no issues at all

 

[fnegroni]

My understanding is that PEN fault protection isn’t about your own home wiring. The fault is at the supply coming into your house and if you detect a PEN fault you must notify the DNO and they must investigate.
Therefore it’s a real danger although rare.
You would need to be touching your car while being charged and at the time a PEN fault occurs.

 

[DixieTGS]

I presume for the device above, it doesn't do PEN protection as the earth doesn't come out of the breaker ? If correct that seems surprising for a device marketed for EV charging.

 

[Caramaddy]

I use the granny charger only. I had an electrician, who installs 7kWh chargers, to check my socket.
1) the socket did NOT have an earth!
2) The RCD needed upgrading.

A new socket solved the earth issue and a more modern RCD fitted.

Well worth having it checked! Better safe than sorry. I agree that you can successfully use a granny charger depending on your mileage.
Works fine - plug gets warm but never hot.
My smart meter shows 60p on the granny - the kettle shows 75p.
The socket in the garage has its own MCB.

No immediate need for an expensive 7kWh charger to be fitted. £1100 buys 15,000 miles of electricity - hope my maths is accurate!

 

[fnegroni]

The maths above make sense, which is why without the government grant, I’m thinking of getting the PEN fault protection on its own but it’s still expensive

 

[Kevin Smith]

We've done 15,000 miles almost all on the granny lead supplied by MG using a 25 metre long 'tough leads' extension cable with integrated RCD and outdoor socket. This plugs into the kitchen socket. No issues, it never runs at more than 1.8kW but our 100green tariff gives us 7 hours a night of cheap electricity and we're retired so that's no issue. We have it scheduled for 2359 to 0700 and once in three months we do the 10-100% in the same way. We've used it used it several times at each of 2 relatives homes - a generation up & down! We never worried about plugging in a 2kW electric fan heater or oil filled radiator and our AGA also pulls 2.5kW for hours on end. Only the latter - professionally hard wired according to the manufacturers recommendation onto a fused spur cooked its fused spur switch which I have replaced and now keep an eye on.
We first heard rumours of dangers at Everything Electric North in May so asked the MG team who were offering test drives and showing the range including the Cyberster. They were quite unconcerned at us using the granny lead all the time - they wouldn't supply something unsafe.
Only because we're moving to Octopus soon I've ordered a zappi charger to take advantage of their EV tariffs which offer free juice or cheap juice at times they choose to charge the car. It was also looking inevitable as after 16 months with one EV we wonder why the other car is still a diesel fossil dinosaur!

 

[mikgle]

I presume for the device above, it doesn't do PEN protection as the earth doesn't come out of the breaker ? If correct that seems surprising for a device marketed for EV charging.

Thats correct but neither does any other appliance plugged in have PEN protection.. your cooker for example.

 

[DixieTGS]

My vague recollection is that when you are standing outside you may become the route to earth if the earth wire has fault on it.

Most outdoor power tools are OK because they are double insulated. But a car (and maybe cookers) are not, so if you are really unlucky you may not be protected without PEN protection.

It would be good if someone who knows for sure could confirm or correct this.

 

[google1901]

I've noticed quite a few comments on using (or not) granny chargers. Having used grannys since 2020 (ZS & since March 23 MG5) I should clarify, Grannys are not the issue. However, as some have intimated, a dedicated circuit + condition of the charging socket is. I have IP66 double socket (replaced when I switched to the MG5) + I regularly check it. Agree risk is always evident (even with your kettle!). So if I may generalise; the cost of IP66 socket replacement (£16-£20 + labour) every 2-3years vs installing 7kw unit. For me doing 5,000 miles per year is a no brainer. The supplied granny is fine, but do monitor your 13A socket(s).

 

[fnegroni]

Thats correct but neither does any other appliance plugged in have PEN protection.. your cooker for example

It’s rare for an appliance to be pulling > 2kW constantly for several hours and being unattended for hours and to be surrounded by people who might be touching it several times even just to open the door etc.

It is a real possibility.
I take extra precautions but it isn’t a good idea.

I’m guilty as charged btw, as I sometimes run my granny charger for several hours.

 

[mikgle]

My vague recollection is that when you are standing outside you may become the route to earth if the earth wire has fault on it.

Most outdoor power tools are OK because they are double insulated. But a car (and maybe cookers) are not, so if you are really unlucky you may not be protected without PEN protection.

It would be good if someone who knows for sure could confirm or correct this.

Your statements are correct but you are confusing two different fault scenarios.. a class 1 appliance such as a car or cooker is indeed relying on a connected path to earth for touch protection, in case of a fault and if that earth connection is broken then there is a high risk of electrocution, amplified outside by means of wetness and less resistance to earth by touch. But that is not a PEN fault, its an earthing fault.
A PEN fault only applies to TNCS earthing systems (whereby the incoming supply neutral is connected to earth, usually somewhere near the mains fuse, and known as PME or protected multiple earthing). You will be able to see a sturdy earth wire coming from the mains head and terminated at an earth block somewhere, called a MET main earth terminal.
However if the supply neutral is broken somewhere in the street or overhead wires (but not the incoming Line or power wire) the path back to true earth is disconnected from the neutral downstream and the power therefore transfers instead to the circuit protective earth wires, as they are connected to the neutral near the fusebox. If an appliance is switched on, the power always goes back down the neutral; no neutral so no return to earth - so back it goes thru the fusebox neutral connection to all the earthed appliances. Ouch!

That is why with a TT earthing system (earth rod) with no neutral connection a PEN fault will be much safer and initially this was the only accepted practice for an EVSE installation. If in doubt, fit a local earth rod for the evse, this is hardwired to earth if you like and must be separated from the household earth.
There is also a common alternative called TNS earthing whereby the earth is provided by the casing of the incoming mains cable and you may be able to see that connection, usually covered in tar just before the mains head. This also is safer than tncs.
Best described with diagrams, so hope I havent confused you all! I am a domestic electrician, now retired.

 

[mikgle]

I’m guilty as charged btw, as I sometimes run my granny charger for several hours.

From the replies, it looks like the majority of people who charge with their granny chargers don't have problems.. this is what you would expect really as if a granny charging lead (called mode 2) were problematic they would never be approved to be used as such.
The problems will mainly occur within the domestic installation, at the plug, socket, cabling etc because any weakness will be found out by the longer load time, hence more stress. This is why it would be prudent to have a professional check done (Condition Report) of the circuit being contemplated for granny lead charging, or else have a dedicated circuit installed

 

[DixieTGS]

Thanks for the clarifications. It took a few re-reads for me to be happy I understood correctly, but that was due to the time of night and not your description.

As to the need for extra PEN protection when granny charging, the small extra risk of a PEN fault causing injury for us is almost 0 as we don't charge often and would rarely touch the car.

By chance I came across some stats on the myenergi Ireland website which said only about 400 PEN faults were reported each year and only about 10 caused injury. It didn't mention if any of them were via an EV.