RCBO connections

Ging Ging

Hi below is an RCBO connected to an outdoor socket and an MCB to a pump. The black cable on the left is the incoming live, neutral & earth.

The live and neutral are connected to the bottom of the RCBO and spurred from there to the pump through the MCB.

Everything is working and when I pressed the test the RCBO tripped. However from my reading of the drawing on the RCBO should the incoming main L & N not be connected to the top of the RCBO and not the bottom?
Would this effect the operation of the device?
Is it ok as it is?
Is it safe?
Is it advisable to change the connections as I have said?

2011

Ging Ging wrote: »

Hi below is an RCBO connected to an outdoor socket and an MCB to a pump. The black cable on the left is the incoming live, neutral & earth.

The live and neutral are connected to the bottom of the RCBO and spurred from there to the pump through the MCB.

This means that the pump is not protected by the RCBO.
Is this deliberate ?

However from my reading of the drawing on the RCBO should the incoming main L & N not be connected to the top of the RCBO and not the bottom?

This will not make any difference to the operation of the RCBO.

Is it advisable to change the connections as I have said?

The work looks a bit rough, but my main concern is that the SWAs have not been glanded properly. These should have SWA glands that connect the armour to the earth connection. The concern here is that a live conductor may come into contact with the armour making it live and this will not cause the protective device will not operate.

Strictly speaking this is a sub distribution board and as such it should have an isolation switch and be clearly labeled. In this case neither device will isolate both outgoing cables.

It would also be good practice to secure the cables well to the wall with clips or similar. Otherwise the cables may become snagged and pull out of the box.

Ging Ging

Thanks for the speedy reply 2011. Yes I know the pump doesn't have any earth leakage protection. An electrician previously told me it could give rise to potential nuisance tripping if the pump was wired through a rcd or rcbo so I'm happy enough to leave it on the MCB until I hear otherwise.

My main concern was that the RCBO for the socket might not detect earth leakage s o its good yo here this is alright.

I take your points regarding clipping, a master isolation switch for turning off everything in the sub board and the glanding and earthing. The armour strands on the SWA cable are infact joined to the earth bar through cable connectors (not visible in photo due to the green insulation tape).

M cebee

top or bottom doesn't matter
but an rcd has to be tested with rcd tester to be certain

2011

M cebee wrote: »

an rcd has to be tested with rcd tester to be certain

+1 this is an important point.

...and that is only one of several important tests that should be carried out.