UK Consumer Unit spare way

[justeez81]

Hi all. I am due to get an EV wallbox fitted so I will be running a new 6mm SWA from under my stairs to the termination point outside. My issue is I have no spare ways for a 32A breaker in my consumer unit for the installer. Is there any recommendations on shifting some load to free up a way for a new mccb?

Consumer layout

Main Switch/RCD/16A cooker/32A upstairs sockets/32A kitchen +outdoor sockets/10A boiler +loft/6A downstairs lights/RCD/6A kitchen lights/6A upstairs lights/6A smoke alarms/20A utility room sockets/32A living room sockets.

 

[Baddegg]

If there’s no spare ways I expect he’ll split the tails via a Henley and put in a small unit dedicated for the ev charger......or put the smokes in with the lights, I’d let whoever is designing it advice mate ?

 

[justeez81]

If there’s no spare ways I expect he’ll split the tails via a Henley and put in a small unit dedicated for the ev charger......or put the smokes in with the lights, I’d let whoever is designing it advice mate ?

Only issue is they have split the consumer unit with
A live and neutral block which has 25mm tails to consumer unit and 25mm tails to a smaller 2 way consumer unit for the loft. The blocks do have a 3rd slot for another tail in each of the love and neutral block. Do you think they might use it?

 

[snowhead]

Has the installer asked you to run 6mm cable?

The installer will sort out what is needed when they come to quote or to do the work.
Nothing you've described will be a problem for them.

 

[justeez81]

Has the installer asked you to run 6mm cable?

The installer will sort out what is needed when they come to quote or to do the work.
Nothing you've described will be a problem for them.

No I am getting a new driveway installed and will pre install the SWA before the EV box is installed. I also intend on doing the cable run as that keeps installer costs down as well

 

[JBW175]

As above, the person installing will know what needs doing and carry out the works accordingly.

Leave it to them and all will be good. ??

 

[JBW175]

No I am getting a new driveway installed and will pre install the SWA before the EV box is installed. I also intend on doing the cable run as that keeps installer costs down as well

Who’s designed the circuit? Have you been told what size cable to use? How longs the run? Have you calculated VD / Zs?

You can’t scrimp on safety, leave it to the electrician...

 

[justeez81]

As above, the person installing will know what needs doing and carry out the works accordingly.

Leave it to them and all will be good. ??

Thanks for the advice but I don't want to be blindsided by a huge quote to upgrade the entire consumer unit if that makes sense

 

[driverman]

Whilst no need to comply with regs, I would suggest lay black pvc ducting for the SWA under your drive.
Something like 50mm diameter Polyducting

 

[justeez81]

Who’s designed the circuit? Have you been told what size cable to use? How longs the run? Have you calculated VD / Zs?

You can’t scrimp on safety, leave it to the electrician...

Thanks for the comment. I have designed the circuit. 8m run of 6mm is fine on VD and Zs. A 6mm SWA is perfect for a 7kW Mode 2 single phase charger

 

[Spoon]

No I am getting a new driveway installed and will pre install the SWA before the EV box is installed. I also intend on doing the cable run as that keeps installer costs down as well

The electrician cant sign off on the cable you have installed if he can't inspect it all. He may also refuse to sign it as he wasn't there when the cable was installed. Best to ask the installer first.
Ask about you installing some conduit for him?

Thanks for the advice but I don't want to be blindsided by a huge quote to upgrade the entire consumer unit if that makes sense

The EV needs a type A RCD. I doubt the RCD in the existing CU's are that type, so may not fit the cable into it. It all depends.
What does the small CU have?
He may just replace this one. Only a site visit can confirm this.
What EV are you getting?

 

[justeez81]

Whilst no need to comply with regs, I would suggest lay black pvc ducting for the SWA under your drive.
Something like 50mm diameter Polyducting

Yes the driveway contractor said he will install one, although a ducted SWA is slightly down rated over that of a laid direct onr

 

[driverman]

Thanks for the comment. I have designed the circuit. 8m run of 6mm is fine on VD and Zs. A 6mm SWA is perfect for a 7kW Mode 2 single phase charger

I’d use 3 core SWA cable
Why not go for 10mm. That will ensure you’re covered re loading plus spare capacity if needed further down the line. Bigger car!

 

[Spoon]

I’d use 3 core SWA cable

Might not need it, depending on the EV..

 

[justeez81]

The electrician cant sign off on the cable you have installed if he can't inspect it all. He may also refuse to sign it as he wasn't there when the cable was installed. Best to ask the installer first.
Ask about you installing some conduit for him?



The EV needs a type A RCD. I doubt the RCD in the existing CU's are that type, so may not fit the cable into it. It all depends.
What does the small CU have?
He may just replace this one. Only a site visit can confirm this.
What EV are you getting?

I’d use 3 core SWA cable
Why not go for 10mm. That will ensure you’re covered re loading plus spare capacity if needed further down the line. Bigger car!

Not a bad idea but the most you'd get from a single phase is EV box is 7kw. You can get 15bor 22kW chargers but they require 3 phase.