Yes, EU breakers, RCD devices etc. do all fit in the DIN rail ok, but that does not necessarily make them 'interchangeable'. I bought an ABB split consumer unit C/W some prefitted breakers and spare spaces at the local brico- [ pics on the way to another thread; see Wiring Horrors, Violation Forum]. The brico now only stocked LeGrande stuff, so I bought Legrande breakers for the extras I required. I also junked some of the ABB units, as they were cartridge fused, in favor of LeGrande units.
The actual internal heights at the busses varied by about 3/16", making the bus connections across the hots and neutrals a nightmare- the Legrande bus copper 'legs' I bought were too short for the ABB units. Luckily, the brico still had some spare ABB bus bars in stock to resolve the problem & they fitted the LeGrande units ok for the spans. Also, very slight variations in DIN rail attachment clip positions between makers, viz the panel apertures, made it impossible to get a neat alignment- yes, they all fitted but not absolutely parallel as I would have liked.
Alan
