Max AMP setting for home charger?

[CCrabtree]

What is the max amperage setting for a Level 2 home AC Charger when paired to the BZ4X?  I will be hardwiring a ChargePoint unit, and the installation manual states that it can support a max load of 50A with an 80A OCPD/Breaker.  But, I do not want to exceed any limits set by the Vehicle Manufacturer.  

[JonathanP]

Not sure what you mean. Still waiting delivery of my car but I've had the EV charger fitted (Zappi) and the electrician set everything up.

The only thing he's said that once the car arrives if it trips out he will come back and adjust settings.

[philip42h]

16 hours ago, CCrabtree said:

the installation manual states that it can support a max load of 50A with an 80A OCPD/Breaker.  But, I do not want to exceed any limits set by the Vehicle Manufacturer.  

As I understand, the bZ4X comes with an 11kW onboard charger, so the absolute maximum it could draw from a 230V mains would be 48A ...

[Mister Mike]

Unless you have a 3-phase power supply, which is unusual for domestic premises, you will only be able to send 32A to your car (7.2kW).

[Mjolinor]

1 hour ago, Mister Mike said:

Unless you have a 3-phase power supply, which is unusual for domestic premises, you will only be able to send 32A to your car (7.2kW).

 

Why is that? Is it a limit imposed by the standards and the charger?

Typical UK single phase supplies are usually protected by a 100 amp fuse, some supplies are 60 amp protected but I do not know any that are under 60 amps so there is no reason why you could not take that from the supply.

[Cyker]

I think it's the wiring too - Probably not rated for much more than 32A, so running more will be risky as the cables will get quite hot. I'm also not sure if you can get standard domestic breakers rated for more than 32A here.

It is certainly possible to have higher, but I've only seen that used in specialist commercial and industrial applications.

 

[adidev]

The device states that it supports up to 50A doesn't mean it will force the vehicle to take that much current. The on-board charger installed in the vehicle is responsible to regulate the charging current depending on various conditions like Battery state of charge, temperature etc.

More important is to check your house wiring. As mentioned above. Using existing wiring might put a lot of stress on it when charging over long period of time. It is always recommended, if the charger will be a permanent solution, to have a separate feed from the consumer unit. Here, you need to take in account (again, as stated before) what is your incomer - 100A/ 60A? Do you have other electric heavy appliances - electric shower, cooker, hob? For example, your charger will pull approx. 48A and at the same time, lets say, you take a shower in your 11kW electric shower - this is another 48A - 96A load on your 100A incomer!!! Forget doing anything else.

If you're not sure, seek advice. It's always better and cheaper than setting your wiring on fire. Installing devices like this should always be assessed by a qualified installer.

[Cyker]

Yeah, inadvertently starting a cable fire inside the wall cavity of your house really isn't fun times...!

My dream would be to have loads of batteries charged from loads of solar panels that I could then charge the car with, but there is 0% chance of that happening while I'm still in London. (and also haven't won the lottery.)

Ironically, if I did somehow get out to somewhere I could do that, the range will probably then become a problem!

 

[Mister Mike]

6 hours ago, Mjolinor said:

 

Why is that? Is it a limit imposed by the standards and the charger?

Typical UK single phase supplies are usually protected by a 100 amp fuse, some supplies are 60 amp protected but I do not know any that are under 60 amps so there is no reason why you could not take that from the supply.

British Standard BS 7671:2018 (IET Wiring Regulations). The maximum current-carrying capacity for a typical domestic circuit is 32A.
Three-phase chargers use multiple conductors.

[Mjolinor]

6 hours ago, Mister Mike said:

British Standard BS 7671:2018 (IET Wiring Regulations). The maximum current-carrying capacity for a typical domestic circuit is 32A.
Three-phase chargers use multiple conductors.

This I know. That is for a ring main but there is no reason why you cannot go meter to car with a specific circuit for the job. Obviously with the correct sized cable and suitable protection.

The feasibility apart, my question is why it is limited, is it about the standards laid down for electric vehicle charge points or belief that a domestic supply will not deliver more or something else?

This whole thing about electric cars is a typical, ill thought out, catastrophe in the making. Thankfully at 68 years old I will not be here to see the collapse of the grid and Mad Max becoming a reality. 🙂

 

 

[philip42h]

2 hours ago, Mjolinor said:

The feasibility apart, my question is why it is limited, is it about the standards laid down for electric vehicle charge points or belief that a domestic supply will not deliver more or something else?

The limitation is imposed by the design of commercially available EV chargers. They are designed to connect to 'standard' domestic distribution panels - so up to 32A per phase.