New 40' container power house build.

michael d

Solar Enthusiast
Are those polarized breakers?

I recently figure out that are not able to interrupt current flowing in the reverse direction due to a fault causing a short in one string. And that was the reason for having breakers.

Solution is either diodes so there isn't any backfeed, or ganging all the breakers together so interrupting of current is accomplished by the ones conducting in correct direction.
yes, I think the use of polarized breakers is where some people run into an extra stumbling block or mistake on their builds. using non-polarized breakers so it will interrupt in both directions in case of an accidental short or fault is the way to go. I like the class T big fuses near the lithium battery. then use the non-polarized breakers as the secondary defense to protect things (and as a switch). the class T fuse is the main or primary safety interrupt that can stop the power of a large DC LiFePO4 battery. there is a YouTube video by "LithiumSolar" that discusses fuses. I think that is a good video to watch and then do the research on what the fuse will do for you. Everybody like breakers, but they may not be able to handle the DC power a LIFePO4 battery can throw out.
Safety is primary to prevent electrical fires. spend more get more. if you have ever had a fire or any type of major catastrophe you know what I mean. Several companies make Class T fuses up to 1000 Amp ratings. I have 400Amp Class T fuses and some 300Amp Class T fuses for battery and inverters. (Along with breakers)
research and questions are key to the best solutions. sorry for the lengthy reply.