Shower MCB

[whazza22]

Client currently has a consumer unit with MCBs but no rcd protection. They want the shower to be rcd protected, so is it acceptable to just replace the mcb with an RCBO?

Or does the whole consumer unit need to be rcd protected?

Also would this require upgrading the bonding or is that just if you replace a consumer unit?

 

[IQ Electrical]

Client currently has a consumer unit with MCBs but no rcd protection. They want the shower to be rcd protected, so is it acceptable to just replace the mcb with an RCBO?

Or does the whole consumer unit need to be rcd protected?

Also would this require upgrading the bonding or is that just if you replace a consumer unit?

An RCBO would be the preferred method, 314.1 requires circuit arrangements to be such that hazards are avoided in the event of a fault, in effect removing the option of a single RCD at the origin.

If the bonding is undersized etc. then the client should be informed and encouraged to upgrade but technically, this should not stop you from making the shower installation safer.