At the risk of once again making it more complex than it really is.


In a 3 phase board will be a 3 phase bus bar. If you are directed by competent product support people to chose the right ones, you can fit single module RCBOs into it, or single module  MCBs for that matter and have single phase circuits one per phase. Or if you prefer to have say all your lights on one phase, then blanking mdules are available so you go fit one miss two up the board, to create a single phase board, Normally you don't do that except for the odd circuit, as if you really wanted a single phase board you should have bought one.


But a 3 phase RCBO with neutral  is harder, as really you need a 4 pole bus bar, and that is not so common, though I suppose it will come, after all we've only had RCDs in common use for about 40 years now.

So commonly  then , a 3 phase MCB goes in the box for the 3 phase load and  a 4 pole RCD goes somewhere else in another  box nearer the load.

Along side it go  a sprinkling of single phase MCBs or RCBOs to feed the single phase stuff.

Here is a pic of a typical "8 way 3 phase"  box from t'interet, to illustrate the key points  (Thanks to Coppice Electrical). Note that this has rather more covers removed than you'd expect if it was to be energised, but shows clearly the sort of thing you want to be asking about.

Here the 3 phase MCB mounts on the right with the Brown black grey cores going out, and most of the  single phase stuff is on the left, but like the cable dressing, that is more about house style than any rules,  (some folk leave it so when you open the cover screws  it is fired off by the coiled up energy of the spaghetti inside, that  is not really the effect  to aim for .. ).

Note that here the single phases are not RCBOs but MCB. If they were then both cores of the T and E would go to the breaker, and a blue neutral tail would go south from the RCBO to the N-Bar.

This one is yet to be fitted with module blanks to cover  the unused  positions of the bus bar, and the cover over the incomer at the bottom.

While the tape flags on the earth lugs are a tad unusual and  I'd have started filling from the bottom not the top, and I like pirahna nuts, but that is just  'house style' again  It is always possible to find something 'odd' with the work of others.

Mike.

At the risk of once again making it more complex than it really is.


In a 3 phase board will be a 3 phase bus bar. If you are directed by competent product support people to chose the right ones, you can fit single module RCBOs into it, or single module  MCBs for that matter and have single phase circuits one per phase. Or if you prefer to have say all your lights on one phase, then blanking mdules are available so you go fit one miss two up the board, to create a single phase board, Normally you don't do that except for the odd circuit, as if you really wanted a single phase board you should have bought one.


But a 3 phase RCBO with neutral  is harder, as really you need a 4 pole bus bar, and that is not so common, though I suppose it will come, after all we've only had RCDs in common use for about 40 years now.

So commonly  then , a 3 phase MCB goes in the box for the 3 phase load and  a 4 pole RCD goes somewhere else in another  box nearer the load.

Along side it go  a sprinkling of single phase MCBs or RCBOs to feed the single phase stuff.

Here is a pic of a typical "8 way 3 phase"  box from t'interet, to illustrate the key points  (Thanks to Coppice Electrical). Note that this has rather more covers removed than you'd expect if it was to be energised, but shows clearly the sort of thing you want to be asking about.

Here the 3 phase MCB mounts on the right with the Brown black grey cores going out, and most of the  single phase stuff is on the left, but like the cable dressing, that is more about house style than any rules,  (some folk leave it so when you open the cover screws  it is fired off by the coiled up energy of the spaghetti inside, that  is not really the effect  to aim for .. ).

Note that here the single phases are not RCBOs but MCB. If they were then both cores of the T and E would go to the breaker, and a blue neutral tail would go south from the RCBO to the N-Bar.

This one is yet to be fitted with module blanks to cover  the unused  positions of the bus bar, and the cover over the incomer at the bottom.

While the tape flags on the earth lugs are a tad unusual and  I'd have started filling from the bottom not the top, and I like pirahna nuts, but that is just  'house style' again  It is always possible to find something 'odd' with the work of others.

Mike.