Chinese MCCB - As-built, polarized or not?

[Sleeper85]

Out of curiosity I dismantled a TOMZN MCCB breaker of 200A.

There is nothing written on the box indicating polarity to respect.








Upon closer inspection of the extinguishing cages I discovered that they were each magnetized in a different direction which indicates that this breaker is polarized and that the direction of the current is important to extinguish the arc in the best way (but I'm not sure and my conclusion makes me think that it is not polarized or at least that this does not matter).

Terminal 1

The bottom of the cage attracts the north.
The top of the cage attracts the south.





Terminal 3

The bottom of the cage attracts the south
The top of the cage attracts the north






Terminal 1 and 3



PS : I have just opened another MCCB same model but 150A version and the two cages are magnetized in the same way as shown in the photos of terminal 1. This shows that the direction of the magnetic field does not matter in operation of this MCCB and confirms my analysis below.


Question for a champion

What would be the polarity of this MCCB ?

Can we help ourselves with the right hand rule ?





If we reread the @RCinFLA posts we understand that when the circuit breaker is oriented correctly (terminal 1 and 3 upwards) the arc will naturally go towards the cage which is located just above the open contact but then the direction of the magnet will either attract the arc or repel it.

Where does the load go on this DC circuit breaker?

Hi. I recently got this type of DC circuit breaker: It's a 2 pole DC breaker, mine is rated for 160ADC, but has same connection drawing as in the picture. I will use it to connect my 24v Lifepo4 battery to my 3k 24v inverter. My question is, where does the load (inverter) go, and where does...

diysolarforum.com

Another interesting article: https://www.linkedin.com/pulse/wrong-application-two-independent-500-v-dc-mcbs-1000-pv-mohit-agarwal

My analysis is as follows :

Knowing that the arc rises in the cage naturally, if the circuit breaker is oriented correctly (terminal 1 and 3 upwards). The magnetic field induced in the cage by the permanent magnet goes from north to south. The cage having a U shape, the magnetic field induced by the direction of the current will attract the arc to the right or left side of the cage but not towards the bottom, we could therefore say that this MCCB is not polarized and that the current can flow in both directions without problems.





See Oersted's Experiment :

What do you think ?

 

[sunshine_eggo]

A polarized breaker is indicated by +/- on the terminals. 1, 2, 3, 4 is certainly ambiguous.

I looked up other models of that with higher current, and terminals are labeled +/-.

 

[Sleeper85]

A polarized breaker is indicated by +/- on the terminals. 1, 2, 3, 4 is certainly ambiguous.

I looked up other models of that with higher current, and terminals are labeled +/-.

Yes I have also seen the other black models appearing to be polarized (the dimensions are a little different). And since I opened my white TOMZN MCCB which looks a lot like those of other sellers I tell myself that it may not have been produced by TOMZN and that the black models come from another factory. To be sure, it may be necessary to buy a black model and open it.

 

[gotbeans]

looks quite a bit different than the 125 amp

lol

 

[Electric Personality]

Amazing they get away with that crap. Once in a while someone over in China gets caught and bad things happen to them if the right people get screwed.