Dual RCD CU

[davidjones89]

if someone can clear this up please, when upgrading a CU to comply with the current regulations, does the new unit have to be a dual RCD to avoid tripping off the entire installation in the event of a fault or is it still acceptable to have just an RCD board

 

[stef]

Hi davidjones,

I remember that this is in the building regs somewhere, downstairs ring and upstairs lights and vice versa
on seperate RCDs. 671 doesn't tell much about that. It might be in part M of the BR?
I'm sure I read it in this forum somewhere some time ago ...

 

[roukel01]

If you go to any wholesaler or even B&Q and purchase a "17th edition board" they'll come with two RCD's as standard. To completely and utterly comply with regs, in an ideal world, each circuit would be on its own RCBO, but this can be costly.

 

[Guest123]

Ol' red says something like "circuits should be installed so as to minimise inconvenience in the event of a fault"

So technically a single RCD board would contravene the regs as all circuits would be lost in the event of a fault........properly inconvenient.

As the lads have said either a dual RCD board with up and down lights and sockets shared over the two, or a main switch board with individual RCBO's for each circuit (mucho expensivo).

 

[PC Electrics]

Or a split load CU with a few ccts on the RCD and the rest on RCBOs.