Can you reduce the MG ZS EV charging current?

[Lovemyev]

It very much looks like the older “Dumb Rolec” unit like I have.
The green trim around the RCBO is the give away, and we all know how unreliable them Rolec branded trip switches can be !.
If it is the older Rolec dumb unit, there is no dip switches inside of the case that could be used to reduce the power.
They are pretty basic inside, only having three major components.
There is the main RCBO trip switch a contactor and a mode 3 communication module that is rated for both 16 & 32 Amps.
Is this the issue I would ???.
If it has the original tethered type 2 cable, check for writing on the charging gun.
It should have its details printed on gun, stating the handling capacity.
It should read 7 Kw / 32 Amps.
The type 2 cable itself can be rated at either 7 Kw 32 Amps or 16 Amps 3.5 Kw which will reduce the charge also via a resistor.
It would be interesting to see an Amp clamp fitted to check on the incoming power first and then the output power from that Rolec to the car.
The 2 Kw’s it’s producing now is about the same as using the three pin Granny lead !.
Something is badly wrong somewhere.

 

[AK OK]

It's charging & nothings on fire so not so "badly"...
The amp clamp wouldn't tell you much more than we know already of course..

 

[Bluesparky]

I think that's a bit naughty 32a feed with a 40a at the end
It's big enough for 7 kW can't remember if theses had dip switches inside to limit charge
Maybe the MGs not reading the resistance of the plug and is defaulting to 2 kW?

the 40a at the end is fine as long as the charger isn't rated above 7kw, what's naughty is the fact you are not allowed to mix circuit breakers of different manufacturers within a consumer unit, also assuming there is an RCD in the consumer unit, there will be no discrimination between the ev RCD and RCD in the board.

 

[N2STY]

the 40a at the end is fine as long as the charger isn't rated above 7kw, what's naughty is the fact you are not allowed to mix circuit breakers of different manufacturers within a consumer unit, also assuming there is an RCD in the consumer unit, there will be no discrimination between the ev RCD and RCD in the board.

I'm pretty sure you your not meant to go higher only lower is allowed on circuit ie the sourcefuse is the highest

 

[Bluesparky]

I'm pretty sure you your not meant to go higher only lower is allowed on circuit ie the sourcefuse is the highest

as the 32amp source fuse is what dictates the maximum load the circuit can supply, in this case the 40A RCBO is basically being used for its RCD properties only. You could put a 100amp fuse at the end of the circuit if you wanted, but you would be wasting your time and money as the 32amp fuse still dictates the maximum load.

 

[Nicko]

Bluesparky is correct. I would have put a 40A type C MCB in the consumer unit as a type C will take an inductive load and 7kw load at 230v is very close to 32A. As long as the cable is rated for 40A I would change the MCB.

 

[Enquirer 62]

The Ohme Home Pro Product manual supplied with the charger recommends a 40A type B MCB for over current protection.

 

[Nicko]

What is recommended in the manufacturer's literature should be what is installed. The manufacturers literate overrides everything else.

 

[N2STY]

The Ohme Home Pro Product manual supplied with the charger recommends a 40A type B MCB for over current protection.

Mine says type C

 

[Nicko]

So a 40A type C MCB is recommended. This is what should be installed and the cable supplying it should be rated for 40A.

 

[Alb]

You may have to go as high as 10mm² for an unrestricted 40A rating.

 

[Lovemyev]

And the difference between a 40 Amp RCB type B and a type C is what exactly, in simple terms please, folks in the know !.

 

[Nicko]

Type C will take a higher inductive load before tripping. Example is fluorescent lights are classed as an inductive load so you would use a type C, but tungsten lighting would be a type A or B. Electric motors should be a Type D.

 

[Bluesparky]

And the difference between a 40 Amp RCB type B and a type C is what exactly, in simple terms please, folks in the know !.

a type D will allow a higher start up current for a very short amount of time, , type A the least, for an example a 100watt LED driver can produce a 75amp inrush current !!!!!! (for a split second)

 

[Bluesparky]

What is recommended in the manufacturer's literature should be what is installed. The manufacturers literate overrides everything else.

as Nicko says , the manufacturers instructions override everything, even electrical regs.

 

[Enquirer 62]

as Nicko says , the manufacturers instructions override everything, even electrical regs.

Slightly confusing as my product manual purchased with the charger in January this year states type B. Nonetheless our thanks to Bluesparky and Nicko for explaining the difference

 

[Bluesparky]

they obviously don't expect the charger to create a large surge on start up, in reality a type b 40 amp mcb will not trip unless it had 3 to 4 times the rated current through it, so it would take 120-160 amps to trip instantly. In terms of a fault, a short circuit would generally create 400-1200 amps thus blowing the fuse or MCB instantly.

 

[N2STY]

So a 40A type C MCB is recommended. This is what should be installed and the cable supplying it should be rated for 40A.

You may have to go as high as 10mm² for an unrestricted 40A rating.

The fly lead which cannot be removed on ohme is 6mm and EV ultra 6mm is rated at 58amp

When I got my ohme installed they used this one

 

[Alb]

Default cable characteristics don't account for de-rating. The level of de-rating required depends on how exactly the installation is done.

 

[N2STY]

Default cable characteristics don't account for de-rating. The level of de-rating required depends on how exactly the installation is done.

What I am saying is you have no option but 6mm cable as that's what is supplied and they recommend 40amp MCB so must be safe