One three-phase breaker, supplying multiple single-phase loads. OK or not?

[Mark42]

Job done.

Everything's standard except for the one 'Workstation' supplied from a single 16A TPN RCBO (bottom right on the DB). The workstation has provision for single-phase loads, including a hard-wired SP car lift. There's a local TP isolator.

I did this because of existing cable limitations (4 cores only) and there being no room for another DB. (I already have 11 sub-mains on my site and really don't want any more!)

I've researched this in detail and cannot understand why this idea might not be OK electrically. Some members here said it's not, but without giving any explanation as to why not. Convince me, and I'll break up my nice new floor, but I'd really prefer not to

 

[Lucien Nunes]

Electrically, as far as the specific original question is concerned, nothing is going to go bang (provided you don't switch the neutral). Organisationally, there might be minor non-compliance e.g. if the manufacturers' instructions for the lift say that it should be on its own circuit. Not sure about your overall VD situation but with that shared final circuit but the starting current of the lift motor may push the VD over limit on the sockets, and the circuit might be considered notionally overloaded due to the likely application of the sockets. But that is not a 3-phase vs. single thing, it would apply to a shared single-phase final too.