I am looking for practical difference between these two. That is, can I use 2P RCBO in a normal house 1phase consumer unit, instead of 1P+N type?

I have used a 2P type in my consumer unit, but it broke when the unit got flooded and is now bypassed. I have came across 1P+N while looking for a replacement.

This is how the ABB RCBO's look like:

The 1P+N has a solid (un-switched) neutral so it only opens the live, the 2P opens both live and neutral.

For a main breaker you must use 2P, for internal circuits 1P+N is ok.

Thanks for a quick reply Crossy.

The 1P+N has a little schematic on the unit showing that N is also switched. That's what got me confused, as they were basically the same.

But I will definitely use 2P unit now.

Crossy, shouldn't the 2P be used only as main breaker? And the 1P only as single circuit breaker?

Crossy, shouldn't the 2P be used only as main breaker? And the 1P only as single circuit breaker?

No, a 2P is fine as a single circuit breaker (at least in the UK regs), theoretically better in fact as it will isolate any N-E faults on that circuit as well.

It's possible that a 1P+N opens the neutral (as in the diagram) but why it wouldn't be labelled as 2P I don't know.