Sub Meter Protection?

[securespark]

RCBO's are great, because if they trip, there is minimal disturbance. They're not so good in that when they trip, you're never sure if it is an overload/SC or an earth fault.

And you'd have to put the RCBO's on the incomer side, too.

17th is a draft doc. at the moment, but in any case, all the proposal is suggesting is that circuits in bathrooms are rcd protected. Your shower will be on the split side, so will be protected. As for the rest, if you want to make sure that your install complies with the 17th, you'll have to wait & see what the final document says!

Personally, I would upgrade the RCD to 80A, given the 40A shower circuit.

 

[JohnD]

I would be inclined to have the cooker circuit moved to the non-RCD side. Cookers are prone to nuisance leakages, usually from the oven element as it ages. Also, yes, agree, upgrade the RCd to 80A/30mA (I don't think there is a Starbreaker 100A RCD)

No need to use RCBOs as you have a split-load CU. You might consider putting the shed on one to save losing house power in the event of a garden fault. But not if you have a freezer out there as you will not be alerted when it trips unless you fit an audible alarm. Be aware that RCBOs are fitted on the non-RCD side, so the RCD will not trip (usually) from a fault on the RCBO circuit.

I presume you have the current model Crabtree Stabreaker where the MCBs have a copper tongue poking out the back (no screw terminals at the botton). You can get single-module RCBOs for these if you need to.

 

[mossiejdm]

Many thanks for the sound advice, will upgrade to 80/30ma RCCB when shower installation is complete, yes you are correct it is the current model, crabtree starbreaker.

Sorry to be a pain, any comments on meter current limitations and total cu load,(applied diversity considered) ie; service fuse 60-80A supplying a 40A rated meter ?... i'm slightly confused on that one?

 

[JohnD]

On the meter...

Most of the time, despite the main fuse and the circuits available, you will be running well under capacity (unless you were running the cooker rings and the shower and a few electric heaters all at the same time).

If you meter did go wrong, you would spot it dribbling molten tar or otherwise misbehaving, and call the company, who would change it. They will generally stand up to quite a lot of abuse and I don't suppose you've had a problem with yours, but I agree it is sensible to change it.