Soldato
Is it?! I have no clue so assumed it’s not going to be good enough without something extra! If only the EV charger could come straight from that, would solve all of my issues!
Home Charger 2022
- Thread starter Infiniteey
- Start date
Is it?! I have no clue so assumed it’s not going to be good enough without something extra! If only the EV charger could come straight from that, would solve all of my issues!
Soldato
80A main feed is what most houses have. I was jealous when I saw my parents had 40A 
Another 32A type B RCD in that CU for the 6mm cable to the charger and you are laughing.
Another 32A type B RCD in that CU for the 6mm cable to the charger and you are laughing.
Soldato
80A main feed is what most houses have. I was jealous when I saw my parents had 40A
Another 32A type B RCD in that CU for the 6mm cable to the charger and you are laughing.
Would 6mm be if it was internal? Think I’m going to have to run a cable outside. The house CU and garage CU are both 80A I think.
Soldato
Yeah 6mm cross section area for 32A current. External cables tend to be armoured, termed SWA.
80A main feed is what most houses have. I was jealous when I saw my parents had 40A
Another 32A type B RCD in that CU for the 6mm cable to the charger and you are laughing.
Not quite. The 80A RCD is not providing overcurrent protection, it just means its rated for a maximum of 80A before it melts.
It entirely depends on what is feeding the garage CU upstream, for all we know its on a 32A breaker in the main CU or even less.
You need to check what is feeding the garage CU upstream. Is is it connected to the main CU or does it go to the main meter tails and is split out there, how big is the cable?
To be perfectly honest, you just need to consult an electrician
Soldato
I split the tails and put a new CU in the garage. 100amp, enough to do two car charges and a hot tub. Pretty straight forward to do.
House has a 100amp main fuse. I must be close to maxing it though overnight.
House has a 100amp main fuse. I must be close to maxing it though overnight.
Soldato
There's an MCB marked "garage" in the main CU so I assume it's going through the house CU. THe tails are already split but I think that's due to having 2 CU in the house.
To be perfectly honest, you just need to consult an electrician
Yeah I definitely will. Just trying to get an idea of options before paying for a charger/install and then having to get a refund if they come out with some crazy install costs.
I had another look today and it looks like the main house CU has a 40A MCB for the garage CU. The garage CU has 3 MCB in it; 6A for lights, 32A for socketsand another 32A fitted but not being used. So I'm hoping the EV charger could go direct to that…if the cable that runs from the house CU to garage CU can take it.
I couldn't see any markings or writing on the flat grey cable that's going to the garage CU from the house CU but I think it's about 16mm wide twin & earth(?).
There’s your answer, the cable between the garage and the main consumer unit must be able to carry at least 40A. The tails won’t be split of the garage is fed from the main consumer unit (assuming the label is correct of course!).
The charge point will top out at 32A, so in theory you could run it off that consumer unit. The downside is that you only have 8A spare to run anything else in the garage that you might want to run at the same time.
Some chargers come with load management which ramp down the charger if the load reaches a certain threshold. That said those features are designed to be used to be used with a main fuse which doesn’t blow until the power draw goes well beyond its rating for a decent amount of time where as an MCB will trip very quickly so I’m not sure if it will work as intended.
If your eligible for the grant, I’d probably get a new cable run in and then that gives you an option to run in a second charger at a lower cost using the existing CU later down the line.
The charge point will top out at 32A, so in theory you could run it off that consumer unit. The downside is that you only have 8A spare to run anything else in the garage that you might want to run at the same time.
Some chargers come with load management which ramp down the charger if the load reaches a certain threshold. That said those features are designed to be used to be used with a main fuse which doesn’t blow until the power draw goes well beyond its rating for a decent amount of time where as an MCB will trip very quickly so I’m not sure if it will work as intended.
If your eligible for the grant, I’d probably get a new cable run in and then that gives you an option to run in a second charger at a lower cost using the existing CU later down the line.
Soldato
The aim is to charge the car at night so nothing else would be using power in the garage. If I did have to charge in the day then at most I'm charging a Dewalt battery or running a Karcher.
I'll have a look at what chargers come with load management as that could be helpful if it works as I'd hope it does (may not though as you say).
Only issue with a new cable is that it would have to run from the external meter, aroudn the front of the house and in to the garage. Which is exactly what I'm trying to avoid as it will be over 15m and visible as it can't be trenched easily and I assume you can't have it running an inch off the ground?
I'll have a look at what chargers come with load management as that could be helpful if it works as I'd hope it does (may not though as you say).
Only issue with a new cable is that it would have to run from the external meter, aroudn the front of the house and in to the garage. Which is exactly what I'm trying to avoid as it will be over 15m and visible as it can't be trenched easily and I assume you can't have it running an inch off the ground?
Well I'm happy to report that I had a Wallbox fitted today for £529 (inc grant). Cheapest EV charger I could find installed. Very tidy job. If anyone is interested give a PM as I believed they have a few slots left in March before grant ends. I'm based in the NW.
Soldato
Neat!