Need to extend a RFC - Zs not good enough

[stevethesparks]

RCBO means you only need to comply with the requirements for RCD Zs however I’d check that earth leakage isn’t going to be an issue if the extended circuit will be used for PC’s

Although not a requirement, I would also conduct a line test to make sure L&N also return a low enough measurement to satisfy disconnection times. An RCD would not detect such a fault.

 

[TheReturnOfHightower]

Thanks for the responses all. Greatly appreciated again, apologies for my delay in getting back to you all, it's been a manic 2 weeks years.

The regulations allow an rcd to be used for fault protection in a TN arrangement in compliance with table 41.5

This is what I've gone with - documented on the certificate that I am relying on the RCD for fault protection as is my wont per chapter 41.

RCBO means you only need to comply with the requirements for RCD Zs however I’d check that earth leakage isn’t going to be an issue if the extended circuit will be used for PC’s

Thanks, only 5 PCs on this RCD and I've got circuits that have never grumbled with 10 PCs on the same model RCD.

I have a few of the pods you are referring to.
make me an offer I cant refuse.
anything over £300 will be instantly accepted and I will even clean the dust off.
they are all second hand and have come out of various boards i have changed.

Not a pod for MEM1, that's MEM2.

What about putting a small DIN enclosure adjacent to board with a B32 breaker inside, fed from the MEM C32? A bit heath robinson but compliant?

I thought and thought on this design, and it just seems a lot of a bodge. The truth is, these MEM1 are old hat now - we need new boards that have room for future growth too. Thing is, we're bidding for grants for a full rewire so they won't give me the cash to update the boards because it would then be money lost should the rewire funding be approved.

Again, thank you for all your help all.