Adding RCD and spur to ring main.

[Johnny1990]

I am looking at a job where I have been asked to extend the ring circuit, which there is no issue. By modifying the circuit, I need to add rcd protection. The c.u is a old MK Sentry MCB board with the ring on a 5930 MCB. I tried to fit a new MK sentry rcbo, but the busbar terminal height is different.
I am thinking of putting a RCD enclosure just under the C.U. I would need to extend the cables by 32A Wagos. The question is could I take a 4mm from the MCB down to the RCD, then from the RCD another 4mm back to the 3 x 3port wagos connecting it to the ring, Is this acceptable? Easier than taking 2 x 2.5mm down to rcd then another 2 x 2.5mm up for space.
The client client also wants a socket added below the c.u. There is no available rcd protected mcbs. I planned on taking a 2.5mm spur from the proposed new rcb/enclosure to the 1 x 2gang socket. Anyone see any issues, non-regs compliance with this?

Hope this all makes sense. I can try and get photos and drawing of proposed idea.

 

[Murdoch]

There is nothing to say you can’t do this but watch your max Zs values on the ring you have extended

i normally give the client the price for what you suggest and for a new CU - and let them choose