13A EV chargers

vantech: 
 

gkenyon: 
 

So, yes, there's not a lot BS 7671 can do regarding people using a standard socket-outlet in a PME installation to supply a caravan or EV, as a lot of people do. 

However, BS 7671 can't contradict legislation, particularly given the DTI guidance (see Page 20).

I think the moral being just because you can, doesn't mean you should.

That I agree with, but we are talking specifically about PEN faults, so if the install is TT or TN-S, there is then no issue with portable EV chargers, assuming the outlets/receptacles are suitable.  

Without a “smart” mode 3 charger, we may have problems with the grid at times, plus of course the 13 A outlet will take a lot longer to charge the car than a 7 kW (or larger) charger. All goes into the mix …

Just out of interest I had a lost neutral today. 

Customer called out for loss of power and he had checked neighbours OK. PME supply tested L and N both live but 0V between them. 230V for both L  & N to  MET and to one end of tester stuck in ground (external meter cupboard). Smart meter dead.

Called Scottish Power out who were there within a hour. Their engineer called me to let me know the  fault was the smart meter (fitted just over a  month ago) had loose connections! He had tried to tell the supplier who had changed the meter but was not allowed to due to data protection! He has told customer to complain to supplier and I will check that he does. 

gkenyon: 
 

So, yes, there's not a lot BS 7671 can do regarding people using a standard socket-outlet in a PME installation to supply a caravan or EV, as a lot of people do. 

However, BS 7671 can't contradict legislation, particularly given the DTI guidance (see Page 20).

I think the moral being just because you can, doesn't mean you should.

That I agree with, but we are talking specifically about PEN faults, so if the install is TT or TN-S, there is then no issue with portable EV chargers, assuming the outlets/receptacles are suitable.  

So, yes, there's not a lot BS 7671 can do regarding people using a standard socket-outlet in a PME installation to supply a caravan or EV, as a lot of people do, except say it shouldn't be done and recommend suitable precautions are taken as in 722.411.4.1. 

However, BS 7671 can't contradict legislation, particularly given the DTI guidance (see Page 20).

I think the moral being just because you can, doesn't mean you should.

gkenyon: 
 

vantech: 
 

The same as touching a metal outdoor tap connected to a PME system, outdoor lighting, heaters, hot tubs on PME. There is risk associated with it all. 

The difference is, the ESQCR specifically mentions a prohibition for caravans and boats being connected to PME earthing arrangement. The issue is perhaps whether you want to stick your neck out and try to differentiate a mobile & transportable unit (717) and a caravan (721 and 708) and an EV on charge (722).

BS7681 has no control over portable equipment, including EV chargers. You could argue the intended use for the socket I suppose, but that would only apply to a dedicated (and labelled?) outlet.

vantech: 
 The same as touching a metal outdoor tap connected to a PME system, outdoor lighting, heaters, hot tubs on PME. There is risk associated with it all. 

The difference is, the ESQCR specifically mentions a prohibition for caravans and boats being connected to PME earthing arrangement, and the DTI guidance on the ESQCR says this is because of the safety issue (see Page 20). The issue is perhaps whether you want to stick your neck out and try to differentiate a mobile & transportable unit (717) and a caravan (721 and 708) and an EV on charge (722).

gkenyon: 
 

Harry Macdonald: 
 

Thanks Mike.

So an old metal cased battery charger sitting on the engine block carries just the same risks as an EV simply plugged in without PEN fault protection?

Even if it were the case, the two clearly do not carry the same risk.

The difference is that an EV is charged very frequently, whereas a vehicle starter battery is rarely charged from the mains.

The same as touching a metal outdoor tap connected to a PME system, outdoor lighting, heaters, hot tubs on PME. There is risk associated with it all. 
 

A 32A portable EV charger with the correct plugs (cee) is surely only a risk IF a pen fault occurs? These fixed installed chargers with built in protection that negate the need for rods don’t protect against voltage potentials between local earth and the supplier earth. 

The 13A variants do pose a risk due to contacts etc, but dedicated EV outlets with 13A sockets are OK for occasional use surely? There are various manufacturers who make 13A outlets specifically for EV chargers. 

Harry Macdonald: 
 

Thanks Mike.

So an old metal cased battery charger sitting on the engine block carries just the same risks as an EV simply plugged in without PEN fault protection?

Even if it were the case, the two clearly do not carry the same risk.

The difference is that an EV is charged very frequently, whereas a vehicle starter battery is rarely charged from the mains.

Harry Macdonald: 
So an old metal cased battery charger sitting on the engine block carries just the same risks as an EV simply plugged in without PEN fault protection?

With respect, that is a bit silly.

When I charge a flat battery, I generally remove it from the vehicle. Occasionally, I use my charger to start a car, but in that case, the duration is short and clearly loss of PEN would be obvious.

Thanks Mike.

So an old metal cased battery charger sitting on the engine block carries just the same risks as an EV simply plugged in without PEN fault protection?