Outdoor Socket Advice

[Bubbauk]

Hi All

I need to install an outdoor socket to charge my new car, it is a hybrid and can charge from a normal socket in about 5 hours so I don't see the need to purchase a "proper" car charger.

I plan to run this to its own dedicated 16a MCB in the consumer unit, my consumer unit was updated a few years back and is RCD protected.

The socket will be installed at the front of the house which is near the consumer unit, I have to run the cable externally and it is only a few meters away.

I am wondering does this need to be SWA or can I use outdoor rated flex?

From looking at the ratings of cables it says I could do this with 1.5mm, is this correct or should it be 2.5mm?

I have attached pictures of the front of my house, the socket will be going where the grey virgin media box is (this is being removed) and my consumer unit is just to the right of the front door.


Any advice on this would be appreciated.

Thank you
David

 

[bernardgreen]

Fit the socket higher than the rain splash area of the wall. This will reduce the risk of water getting into the electrics and you will not have to bend down so much when putting the plug in and out

Fit a two pole isolator ( disconnects both Live and Neutral ) inside the house. This will enable you to fully isolate the socket if ( when ) the socket is damaged and/or water logged. Switching off the Live is not enough, a Neutral to Earth fault will cause the RCD to trip. The isolator will also prevent people stealing electricity when you are not there.

 

[ericmark]

The problem is safety, yes you can charge the car, but the car charger can freeze a standard RCD, so the charging station has a cut out which will detect DC, and at 6 mA DC it will auto disconnect so you can use a type A RCD, without that cut out you need a type B RCD, and the type B RCD is rather expensive, so cheaper to use the proper charging station.

The problem with electric car chargers is a fault can cause a RCD to freeze, so a fault in the house will fail to trip the RCD, and from what I can see from the picture you have type AC RCD so the one supplying the car will need changing anyway, but a type B is likely more expensive to a type A and a proper charging point.

 

[Aragorn84]

Having spent a while on some EV forums, i can tell you long term charging on a 13A socket will not end well. They're just not made for continuous high load and will eventually burn out and melt.

I would suggest you at the very least go for something like the OHME charger and fit a commando socket for it.

If your an Octopus Energy customer they have a deal on where you can buy the Ohme charger for £200. They sell a 13A version and a Commando version. Get the commando one, and have a suitable commando socket fitted for it.

 

[Aragorn84]

The problem is safety, yes you can charge the car, but the car charger can freeze a standard RCD, so the charging station has a cut out which will detect DC, and at 6 mA DC it will auto disconnect so you can use a type A RCD, without that cut out you need a type B RCD, and the type B RCD is rather expensive, so cheaper to use the proper charging station.

The problem with electric car chargers is a fault can cause a RCD to freeze, so a fault in the house will fail to trip the RCD, and from what I can see from the picture you have type AC RCD so the one supplying the car will need changing anyway, but a type B is likely more expensive to a type A and a proper charging point.

So called "granny chargers" have the RCD protection built into them. They're designed to be jammed into any old 13A socket. So in theory it shouldnt matter that there is an AC RCD on the board.

 

[ericmark]

So called "granny chargers" have the RCD protection built into them. They're designed to be jammed into any old 13A socket. So in theory it shouldnt matter that there is an AC RCD on the board.

I is not RCD protection for the car charging socket which is the problem, the problem is when it causes a DC current, which in turn freezes the main RCD so rest of house ends up with not protection. It seems some charging points auto turn off at 6 mA, but that only works with a type A RCD and already has a type AC so the RCD would need changing.

 

[Aragorn84]

There should not be a DC current unless there is a fault, and if there is a fault, the charger itself should turn off. Thats the point of putting all the protection into the charge unit.

But if you want to swap the RCD, then go for it, assuming its available and cheap enough.

 

[JohnD]

The 13A charger can be an advantage if you are a person with solar panels. Judicious timing will often enable you to charge the car using "free" electricity.

 

[ericmark]

and if there is a fault, the charger itself should turn off

Two points, should is not will, and second most chargers are designed for a type A not type AC so will only turn off at 6 mA DC which is over the amount which will freeze a type AC.

 

[JohnW2]

... most chargers are designed for a type A not type AC so will only turn off at 6 mA DC which is over the amount which will freeze a type AC.

Ah - you seem to have done better than I have at discovering some facts. Where did you learn that 6 mA DC is "over the amount which will freeze a type AC" ?

I have to say that, if true, that 6 mA figure greatly surprises me.

Kind Regards, John

 

[ericmark]

6 mA is the tripping correct for most charging pods which state must use type A RCD, so it does seem the limit for type AC is less than 6 mA.

In my house all RCBO I would not worry, chance of item freezing the a RCD at same time as fault is slim, but with multi circuits from same RCD that is rather a high chance of multi faults.

 

[JohnW2]

6 mA is the tripping correct for most charging pods which state must use type A RCD ...

That is true, but ...

.... so it does seem the limit for type AC is less than 6 mA.

.... but that is a quantum jump in reasoning (i.e. assumption) which could be wildly incorrect (at least an extremely 'cautious' assumption). It therefore seems that you probably have not done any better than I have at ascertaining any actual facts.

As I said, although I may be wrong, I would be very surprised if 6 mA DC could 'freeze' a Type AC RCD.

Kind Regards, John

 

[conny]

"I plan to run this to its own dedicated 16a MCB in the consumer unit, my consumer unit was updated a few years back and is RCD protected."

At the moment you don't have a spare 16A MCB. Are you proposing to fit one to the right of the left hand RCD?
Are the rules in Belfast the same as in England? You could be given advice on here which may not be applicable in your area.

 

[winston1]

Some years ago I put a diode in series with my Christmas tree lights to make them last longer. They take more than 6mA. Have I endangered my family over Christmas? I must do some tests next Christmas.

 

[ericmark]

I think there is a problem with DC, but what is not clear is the extent of the problem. @conny comment shows the problem where MCB and RCD use seems to be miss understud.

And @winston1 also makes a good point as except with TT supplies the RCD is additional protection not the only protection, so even if the RCD is rendered useless to have enough faults for the DC to cause the tipping of the scales.

How ever when it does go wrong as with the Emma Shaw case, it is rarely one fault, but many faults all added together, so like saying now we have crush zones and ABS brakes in our cars there is no need for seat belts.