MG ZS EV using V2L and protection RCD/MCB?

[DudeMG]

Hi all,

I've been using the V2L and all working fine. The car is kept locked inside our garage, so all good there.

I'm wanting to run a proper cable through to the house utility room to run the Washer and Dryer on the car when I can as cheaper.

Thing is, is it worth including an RCD/MCB before going to the first socket for more protection? I suspect it is. The car does have overload protection, but unsure about shorts / issues with appliances. I don't want the damaging the V2L on the car or worse, cause a massive issue, hence the RCD.

One issue is the lack of an earth as it's off-grid, so unsure if an RCD is OK solution. Maybe just a single 16 amp MCB instead? RCD to trip with shorts / overload, but the earth is missing, so might cause issues there?

As I'm going to run it properly, prefer something was between the car and the sockets. Any advice is appreciated, thanks.

 

[aserraric]

An MCB is never a mistake. As you already noticed, there is no earth, so an RCD will not work. You could use an LIM (line isolation monitor) instead, since V2L is effectively an IT network (isolated to ground).

BTW: An RCD does NOT trip on overload, unless it is a combined RCD/MCB. RCDs only react to leakage to ground (but are much more sensitive than MCBs).

 

[Tim Green]

Going by first principles, any isolated supply (as is V2L) is inherently safe as you would need to touch both poles to get a shock. However, as stated an RCD won't work because it would not recognize leakage to earth. A fuse or MCB would help but only limits over- current so would have to be a high value. In the house you really want the RCD's to work which means you would need to earth one side of the supply from the car. I cannot see a problem with doing that as long as you then use both an RCD and MCB or combined unit. I would be reluctant to back-feed into a socket in the house as it would have to go backwards through the RCD/MCB which may cause problems. You should get wiring checked by a qualified electrician or preferably electrical engineer.

 

[DudeMG]

This is for off-grid use only. No way back feeding to house and will be out-of-phase! Highly dangerous. Plus voltage is only ~220 volts from car, which is too low if I'm honest, would have been better at 230v, but presume they doubled from 110v to 220v depending on the country, (I could be wrong).

An MCB will fit my purpose, as it trips a lot faster than a standard plug fuse. Only use max 2 kW load, but want some extra protection between car and appliances. The safer the car is, the better!

Thanks for the info. Most users will just use the V2L and a standard socket extension, which is OK, but I want a bit more to be safe as will be running cable on the wall with sockets, which will be only used for V2L.

 

[Tim Green]

Yes, the mains input must be disconnected if running the house. I have a petrol genny for emergency use, but have not had to use it in anger yet. Long may that be the case.