Are 30mA split load consumer units non compliant under 18th edition

[stefanli69]

Hi All,

Just wanted to see what peoples opinion is

is installing a 30ma Split load board compliant/ non compliant under the 18th Edition or you have to use RCBO's for each final circuit?

BS7671:2018, Page 155 regulation 531.3.5.2 is a note which says on TN systems which states " Exept where particular restrictions on selectivity applies; Several circuits may be protected by the same device"

Views?

 

[Pretty Mouth]

The IET seem to think they are compliant, as they are suggested as a method of providing RCD protection within installations on p36 of the OSG

 

[MJPD29]

Rcbos are better but absolutely nothing wrong with installing split board

 

[Dustydazzler]

If you could fit an rcbo board for just a fraction more money than a split rcd board then why on earth would anyone fit the rcd board.
an rcbo board or better in every way thinkable

 

[ferg]

If you could fit an rcbo board for just a fraction more money than a split rcd board then why on earth would anyone fit the rcd board.
an rcbo board or better in every way thinkable

It's only a fraction more if you use lewden or the like.

How often are you expecting the RCD to trip in a normal domestic?

 

[Deleted account]

How often are you expecting the RCD to trip in a normal domestic?

very rarely, but when it happens the disruption to loosing half the houses electrics is why RCD split board is a poor choice.

 

[ferg]

very rarely, but when it happens the disruption to loosing half the houses electrics is why RCD split board is a poor choice.

Granted it's not the best solution but it is a cost effective one and compliant.

I certainly would not call it a poor choice as like everything there is a cost vs benefit element to it.

 

[littlespark]

They are still compliant, and the disruption to end user is minimised if half the house goes off is initial design.
Upstairs lights with downstairs socket....
Cooker on different rcd to kitchen sockets

It would be simpler for us just to say it has to be all rcbo now to comply, but mr customer can find split boards in his local diy.com retailer

 

[gazdkw82]

Commonly installed but the regs do state that the failure of one circuit shouldn't effect another circuit.

Similar situation with SY cable. It's not a BS7671 recognised cable but widely used.

 

[Ian1981]

Commonly installed but the regs do state that the failure of one circuit shouldn't effect another circuit.

Similar situation with SY cable. It's not a BS7671 recognised cable but widely used.

More to do with one circuit breaker protecting one circuit disconnecting will not effect another , as the regulations allow more than one circuit to be collectively protected by one rcd.

 

[gazdkw82]

More to do with one circuit breaker protecting one circuit disconnecting will not effect another , as the regulations allow more than one circuit to be collectively protected by one rcd.

Pretty sure that's the same thing