Circuit breaker question

[Sportzfann]

I have a 50 amp 2 pole dc breaker I want to use for my over current protection for my victron CC 150/45 I am using one as a disconnect on the solar feed from the panels to the CC I really only need to protect the positive side of this circuit.
My question is can I safely use just one line of this breaker for my protection? I already have the breaker and then wouldn’t need to buy a 50a fuse. My understanding is this breaker should protect the positive or the negative if it should exceed the 50a rating.
thanks,Sparks

 

[sunshine_eggo]

Picture where we can actually read the breaker markings?

Assuming that's a DZ47Z-63, it's a polarized breaker, so you need to use both.

A 2 pole breaker with + and - labels rely on opposing polarity to be able to trip the breaker unless they explicitly state otherwise.

 

[Sportzfann]

Yes it’s a polarized breaker 50 A with + & - identified on the breaker, I purchased a 50a inline fuse just in case, but wasn’t sure I would need it.
thanks for the heads up.

 

[freepower2023]

On this breaker which is rated for 125 amps is that for both poles or is each pole rated 125 amps