DC MCCB is this correct

[Greglsh]

I bought this DC MCCB and want to use it in my DIY lithium battery it has a Seplos v2 10E 200amp BMS and 280ah Eve cells. What I need to know is this the correct unit or does this only allow current to flow in one direction? Thanks

DC MCCB 250A Circuit Breaker - 2 Pole - Micro Robotics

The Solar DC Moulded Case Circuit Breaker (Series YTTM1-250/PV2) offers overload and short circuit protection for your DC electrical system. With 2 poles, a Type C configuration, and 25KA breaking capacity, it meets IEC 60947-2 standards. Its compact desi

www.robotics.org.za

This is another drawing I found online, I have the 2P model

 

[JBertok]

DC breakers are polarity specific because of a magnetic component involved in preventing arc when tripped - and that can only work in the right polarity. A 2P breaker allows for bi-directional protection because the two poles are wired in reverse polarity from each other. In that way, no matter which direction power is flowing the circuit has overload protection because the arc will be deflected on one pole or the other.

 

[SparkyJJO]

That is normally true but those are supposed to be polarity agnostic.

 

[JBertok]

Yes, but only when connected like the diagram shows in the 2 circuit examples under 2P. No matter which way current flows in those examples, one of the two tied breakers will trip under proper polarity because polarity is opposite between each pole, and that will break the arc.

 

[OffGridForGood]

In the case of a DIY battery, my main concern is only with discharge breaking, where a short circuit is possible. I am not (as) concerned with breaking under charging condition, where the available currents are limited to the PV source, and BMS control will cut off charging over current if this were to occur.