Anyone know the practical issues with a type AC outdoor socket?

ComicGeek

AC and 230V for Type 2 charger - the EV then converts to DC internally as all battery charging is actually by DC, but that is controlled by the EV's internal battery system.

DC and 400/800V for rapid chargers.

So the solar PV generates electricity in DC, then converted to AC by the inverter, sent to the EV as AC, which then converts it to DC to charge the battery.... with losses at each stage as it converts...

WIAWSNB

Cheers.

The 'charger' box is therefore more of a 'control' box, which guards against live voltages being present at the car plug when not in use, and presumably only allows power through when plugged in and turned on?

Astonishing, it only has a push-on rubber cap over the end! 

Most folk appear to leave theirs powered up all the time. 

Heedtheadvice

....and the car load has rapid switching so usually does not load the positive AC cycles identically to the negative cycles thus loads the chargers/mains unevenly. As it is a switching power supply ( to convert mains voltage to a much higher DC voltage to apply to the car battery) there can be uneven switching at high frequencies too.

Both those aspects create a very small offset in the AC loading on the charger and thus the main supply. offset = DC.

Under a fault condition ( such as a leakage from the charging circuits to the chassis because of dampness or a component failure) this can mean an AC or DC ( or both ) leakage current. If that is big enough then there can be lethal voltages that can be touched.

Type B will trip for all those fault conditions maintaining  safety.

AC Type is fine for general protection outdoors.

WIAWSNB

Heedtheadvice said:

....and the car load has rapid switching so usually does not load the positive AC cycles identically to the negative cycles thus loads the chargers/mains unevenly. As it is a switching power supply ( to convert mains voltage to a much higher DC voltage to apply to the car battery) there can be uneven switching at high frequencies too.

Both those aspects create a very small offset in the AC loading on the charger and thus the main supply. offset = DC.

Under a fault condition ( such as a leakage from the charging circuits to the chassis because of dampness or a component failure) this can mean an AC or DC ( or both ) leakage current. If that is big enough then there can be lethal voltages that can be touched.

Type B will trip for all those fault conditions maintaining  safety.

AC Type is fine for general protection outdoors.

But that has never happened in reality.

And many folk plug their Type-Twos straight into a conventional socket. Some have lived to tell the tale. 

WIAWSNB

Bright and dry but cool day, came back from walk and tried to charge t'car.
Amber. Stubbornly amber. Different sockets, no difference.
Took the cable indoors and set it on top of a nicely warm storage heater. Tried it after a half hour, and it's working again.
Perhaps not as IP as they claim?

Heedtheadvice

Ahem! Good it only dampened the low power electronics, eh,

WIAWSNB

Tee-hee

FFHillbilly

WIAWSNB said:

Heedtheadvice said:

You do seem to have your electrical theory back to front somewhat.

The rcd type needs to be aporopriate to the equipment that it is powering. It is not a question of the type of current the powered device is producing or as you wrote 'emitting DC waveforms'. It is a question of the type of fault current that the rcd can detect. This is a safety issue so should not be ignored 'the only 'issue' should be that the RCD might not trip at all. ' as you posted and that should not be ignored.

Best rcd for that job is an appropriately rated type B. That type will detect fault currents of many types. Suitability is for  wide range of electronic loads so should be suitable for whatever car you Connect.

Current rating of the cables (and idealy in this situation including the connected equipment ) should be limited by an appropriate circuit breaker not just the cable to the outdoor socket.

Lengthy charge time can lead to overheating ,( as I think you realise) and the orange light helps to indicate a problem in that area. - just at the plug contacts though? The fact it illuminates from cold initial switch on indicates the monitoring itself has a problem. Possibly moisture in the granny charger amongst others things.

That needs diagnosing and repair...or maybe just replacing with a suitable one for outdoor use.

So the only remaining issue is whether the RCD I am using - a type AC - could be compromised in its safety-effectiveness when used with an electronic device such as this charger. The answer would appear to be 'yes', but my take on this is 'possibly', and not worth seeking to replace it at the moment.

the RCD choice would be less important that the lack of PEN fault protection you have using a Mode 2 (Granny lead) charging cable

WIAWSNB

FFHillbilly said:

the RCD choice would be less important that the lack of PEN fault protection you have using a Mode 2 (Granny lead) charging cable

Could you explain, please? 

FFHillbilly

a fault in the distribution network could cause the earth conductor, and all circuit protective conductors and bonding conductors (thats all the green and yellow wires) to become live. 
it's been a possibility ever since the PME or TNCS system was used, but it's more of a problem with EV's that are parked outside because it is possible to touch the EV whilst stood on the earth, and you could receive a shock.
all 7kw hardwired chargepoints have been required by the code of practice to have PEN fault protection for years now

this video from 5-9 minutes explains it

https://youtu.be/UxWBGeTONGc?si=S2IgMeIT_JSY_7VP&t=300

in the UK around 400 PEN faults happen annually and it is on the rise with the ageing network and increased demand on the network