I just tore down a 2 pole breaker. Your explanation makes sense for the single pole. But because these breakers are exactly the same the +/- markings for the breaker on the right is reversed. This means the current is moving through the breaker on the right in the reverse direction. How does this safely trip the breaker?
I just tore down one of my 2-pole Chtaixi's TXC65Z-60, DC12-110V MCB. And both poles were also exactly the same. They have +/- markings too, but the marketing literature is ... confused to say the least. It says to follow the +/- markings for best practices, but it also says that the breakers don't care about polarity. Since no matter how you hook the breaker up current flowing through one of the poles will be opposite the current flowing through the others, that means either this 2-pole breaker is not polarized (despite having + and - markings), or it is polarized and it assumes symmetrical/opposite currents correctly breaking the ARC on one of the breakers when they both trip. Breaking the ARC on one breaks the current path for both (usually). The breakers do trip together. There is of course the tie on the handles, and there is also a little plastic piece between the two housings that cross-trips between the breakers internally. Oh yah, no magnets in the ARC-break for this 2-pole breaker either. The plastic housing that normally contains the two magnets is empty. All the other trip mechanisms are intact and operate as expected. But I can't really tell if this breaker is actually unpolarized, or it isn't and depends on current symmetry, or it's some deficient piece of garbage.
No, you can't. Even if you take off the cross-piece on the handle, there is an internal cross-trip as well. And the 2-pole breaker (if a DC breaker) might or might not depend on the current going opposite directions between the two poles.
DC vs AC breaker is only about ARC when tripping the breaker, AC breaker might not be good enough in arc extinguishing which can burn down your house, or hit you with piece of destroyed breaker. So it might work, you can try it, but DC breaker is recommended
