UK New CU, Arc Fault Protection and future proofing

[AndyRob]

My electrician has just finished doing some work and testing for me. Later this year I am going to build a new extension to my house and he suggested fitting a new consumer unit now, with extra populated ways, in anticipation of my future need for additional circuits.
He couldn't quite remember the implications of the 18th Ed, Amendment 2, in the context of my 'normal' domestic property - except that it does have a 3-phase supply for heating, cooking, showers, my workshop and an EV in the future). My old CU has no spare ways and though it has a 'split' for an RCD it has no RCBOs.

I think he said that if he fitted a new CU now, and fully populated it with a bunch of RCBOs including some for the (as yet) non-existent circuits, I could avoid a futurerequirement for more expensive RCBOs with AFDD built in (within 6 months of March 2022 ?) . Perhaps there is a CU with just one AFDD that can protect all circuits?

But if there isn't such a CU (with an AFDD covering all circuits) he thought I may have to have AFDD RCBOs for the new circuits when they are wired in rather than being able to connect the circuits to the RCBOs I can have pre-installed now.

It's not that I'm a cheap-skate, or don't appreciate the potential benefits of AFDD, but the electrician thought AFDD RCBOs would be much more expensive, in the sort term at least, and I could upgrade later when they should be much cheaper.

Any opinions would be welcome - and also for a CU manufacturer as, apparantly, a matched set is desirable. How about Fusebox?

 

[westward10]

Problem is the new circuits may well require AFDD whether you have a new consumer unit or not. The only way around this is to yes replace the consumer unit and design the installation now then it will be subject to the previous standard when it was designed.

 

[timhoward]

think he said that if he fitted a new CU now, and fully populated it with a bunch of RCBOs including some for the (as yet) non-existent circuits, I could avoid a future requirement for more expensive RCBOs with AFDD built in (within 6 months of March 2022 ?) .

This is plausible - we are all waiting to see what joy amendment 2 brings us and the draft for public consultation did seem to require AFDD's in many situations. So it sounds like good advice, and I said something very similar to a customer last week.

Perhaps there is a CU with just one AFDD that can protect all circuits?

I don't think this is likely, unless the AFDD protects an entire sub-main, but that would causes other issues.

Any opinions would be welcome - and also for a CU manufacturer as, apparantly, a matched set is desirable. How about Fusebox?

Matched set not strictly required but easier for electrician and you as they will all look and feel the same. Fusebox do indeed make a great product and it's my go-to board for most situations.