Solar PV going in - Time to replace consumer unit?

[davelittlewood]

Hello,

DIY'er here looking for some advice.

In March 2023 we should be getting 5.5kW of solar PV going on the roof feeding into the current consumer unit.

The current CU is a Wylex, probably about 15 years old, plastic, 100A main switch with 2 sets of RCD protected MCBs.
Installation last inspected in 2014 when we had some alterations made to the kitchen and Minor works cert issued,

One of the MCBs feeds an unused isolator in the airing cupboard that once fed a shower (now removed), so the PV installers intend to use this spare MCB, no problems there.

I'm wondering if it's worth:
a) having an inspection done before the solar PV gets installed
b) changing the CU to a metal clad one to meet current IET regs and swapping from MCBs to RCBOs

Cheers,
Dave

EDIT: for b) I mean getting that done, not doing it myself. Done it in the past and I'm sure I could do it safely, just know I'm not allowed to anymore....

 

[westward10]

They cannot connect from the mcb of a dual rcd consumer unit and they should realise this.

 

[littlespark]

Is there not still a 4kW limit on domestic PV? Or was that just while there was FIT offers?

They could install a small garage board off Henley’s and reroute the shower cable into this.
Not using the existing CU at all.

 

[davelittlewood]

Is there not still a 4kW limit on domestic PV? Or was that just while there was FIT offers?

They could install a small garage board off Henley’s and reroute the shower cable into this.
Not using the existing CU at all.

Never was a 4kW limit.
<=4kW only had to inform grid after installation.

4kW pre-registration is needed

 

[Gavin John Hyde]

Is there not still a 4kW limit on domestic PV? Or was that just while there was FIT offers?

They could install a small garage board off Henley’s and reroute the shower cable into this.
Not using the existing CU at all.

as others have said all down to DNO and whether you are going down G98 vs G99

I did a G99 application recently for a 7.8kW system across 3 roofs all at different orientations to south. Told DNO happy to put a grid export limit on at 3.7kW, they surprised us and came back with go ahead with grid limit set at 5kW.. its never going to produce that as the generation will vary as the sun path moves thorughout the day.

I would likely fit a small board for the OP's scenario. need not cost too much either. Might be able to move the mcb off the rcds bur by time you allow for SPD etc its easier to go for the small board.

An EICR is not a bad idea though... will let you know if there are any hidden issues. nothing wrong with a plastic board if Ip rating and all connections are tight and secure.