Do note although these units switch the neutral there is no overload detection on the neutral so not the same as the double width units.
If that's true, it makes some sense, given the lack of space. I don't see it as a significant problem - if enough current is flowing in the neutral that one would want the overload part to trip, there surely would be the same current in the corresponding L - or, if you're going to postulate an incredibly unlikely cross-circuit fault, in the L of some other protective device?
Kind Regards, John
If the neutral was taking return from other device then the RCD part of the unit would cause it to trip so in real terms impossible to get overload on neutral which is not also on the line.
The question was are all RCBO's the same and my answer was to show even from same manufacturer they are not the same. There as many options. We tend to always fit type AC and I know with a caravan and boat I had problems getting a type A when they were using a simulated sine wave inverter.
I see nothing wrong with the owner buying the parts but think it's really down to the electrician to stipulate what is required.
I was surprised that in my mothers house the RCBO's supplying the kitchen have never tripped. Yet my RCD's have series of trips then a time of no tripping clearly technology has progressed since when mine were fitted some 25 years ago. With the exception of X-Pole most RCD's do not tell you how good they are at rejecting unwanted tripping and I am sure other electricians have like myself tested a RCD with a RCD tester and it has passed but still seems to trip on a regular basis but swapping it has cured the problem.
OK my tester is 1/2, full, and 5 times with no ramp but bitter experience has shown me it's not always down to tangible reasons why a RCD trips. I have many times gone to reset one of the pair of RCD's in my house without first switching off all MCB's and the action has tripped the other one of the pair. Without an oscilloscope and the like it would be near impossible to compare RCD's but in the main it's not the domestic electrician who will realise what makes are good and which cause problems as once fitted we walk away. The industrial electrician however does see how often RCD's trip but will in the main use more robust units single width units are not used that much in industry.
So very likely there are very few who can really say which makes cause the least problems. As electricians we are more interested in which boards are easy to work with. We will be more likely to select a make which will allow things like locking off. I know I have selected makes because we already have the lock off clips in our tool box don't want to carry multi-makes of lock off devices. I also for same reason looked for consumer units with lockable lids. In domestic I would think this is not really an issue.
At one firm two makes were used one for when we were happy for fitters to be able to open and re-set another for electricians only.
All these would not be valid reasons to select with domestic.