In article ,
"Christian McArdle" writes:
OK.

Assuming that the RCBOs are double width, I guess that I need at least a

You can get single width ones, although it may depend on the make
of CU.

17-way consumer unit. Did you put your RCBOs side-by-side? I read
somewhere
on this NG that a RCBO can "trip" an adjacent RCBO.

You can put them side by side, no problem.

Check the manufacturer's spec. It varies, and isn't just related
to RCBO side-by-side -- in one case they can't be used with MCB
of 40A or more side-by-side IIRC.

--
Andrew Gabriel