Am I missing something?

[pc1966]

Am I right in saying Solar should be on its own RCBO or MCB and definitely not on a shared RCD as this inverter can take up to 5 seconds to disconnect ?

That is an important but different point. I have seen a PV install on a shared MCB, so the rest circuit of the circuit could get 16A from the MCB and another 16A or so from the PV under full sunlight. I.e. now 32A from an overload point of view.

OK, under fault the inverter shuts down, and this was Scotland so full sunlight is a rare event, but still...

The OP's issue is the whole installation had a 30mA RCD providing the "additional protection" needed for the likes of socket outlets, etc, and by changing that to 100mA it no longer is able to adequately protect against the risk of electric shock as someone could well have grasped something live and been unable to let go, is entering heart fibrillation, and the RCD is still not seeing its trip threshold.

Had it been a 100mA delay RCD up-front like in a TT system along with 30mA RCD or RCBO for sockets, etc, it would be fine, but now it merits C2/C3 on an EICR and basically is a stupid thing to do.

 

[Zlodej]

Am I right in saying Solar should be on its own RCBO or MCB and definitely not on a shared RCD as this inverter can take up to 5 seconds to disconnect ?

You should think of an solar inverter as another source of supply As such You are right. As even if the RCD is left as 30mA it is unable to protect devices sharing its bushbar from issues when inverter is supplying power. You can think of it like a brown wire around the RCD. the lifting the RCD rating is just an extra homeopathic remedy here

 

[GLENNSPARK]

It's a bit like the air con guys that persist in using D curve breakers on their circuits that'll never meet times...

You just know it's never seen a loop test...