Does SPD MCB size matter?

[oscar21]

See Reg 531.3.2 unwanted tripping (ii) rcbos should be considered. Also see section 314

The way I read that is if you expect tripping then minimise it. Under a normal situation in a domestic setting you don't expect any RCD to trip whether its an RCBO or dual RCD board. However if you have a bank of computers that have a bit of earth leakeage then you might get unwanted tripping so use RCBO's instead.

 

[Flanders]

The way I read that is if you expect tripping then minimise it. Under a normal situation in a domestic setting you don't expect any RCD to trip whether its an RCBO or dual RCD board. However if you have a bank of computers that have a bit of earth leakeage then you might get unwanted tripping so use RCBO's instead.

The reg states it just something to be considered. So its up to you if you choose to follow it. I prefer to use separate rcbos, but if the spec requires a split load board thats what will be installed . Just to add regarding spds. Hagers connect straight to the main switch with no OCD in the board

 

[oscar21]

The reg states it just something to be considered. So its up to you if you choose to follow it. I prefer to use separate rcbos, but if the spec requires a split load board thats what will be installed . Just to add regarding spds. Hagers connect straight to the main switch with no OCD in the board

So do the Wylex and Crabtree ones, the first one I did I put the earth in the bottom and then thought why is there an earth position in the top as well. I'd set the board up with a space to the right of the main switch as well so it was all a kerfuffle to put it right again. I wish manufacturers would all stick to a similar design.