Manual Reset Circuit Breakers VS Fuses; which is best, or... approved ?

Mr.Cockburn

Hi !!
I will be soon switching to a Victron 250/100 charge controller and speaking with a rep at a local store he was telling me that Victron does not approve the use of manual reset circuit breakers (which I'm currently using) and that I should use a fuse instead.

Any truth to this to your knowledge ? 
Why would a (type 3) manual reset such as the one I included as a reference (see picture) not be approved by Victron ?

Thanks for your input !! 

SumPower

My experience with these type breakers is in a marine enviroment and was for battery voltages in the 24 volt DC range.

If they are rated for the 250 Volt DC of you Victron MPPT controller I would certainly be surprised.

Up in smoke if they don't have the voltage rating.

Then there are Amperage Interrupting Current ratings of breakers and the 24Volt DC ones I used were only good for 3000 amps before they would self destruct. Smoke, sparks and damage.

If you could post the actual product specifications someone here would be able to help you more.

Mr.Cockburn

Here is what I could find Spec-Wise. I do know they can safely handle high amps at low voltages (up to 48v) because in my 12v system they have been marvelous for the last 10+ years. I need to change a 100A for a 120A because of the new Solar Charge Controller but my local shop said they are not made for "constant" amperage and should be used more like a circuit overload protection. Something related to these being Thermal breakers vs fuses or something along these lines. 

***Oh.... Just thought of this though because of your comment ; my current voltage from panels to controller is (now) 46v **but** with new panels this will change to 150v so... These are not ok to use with my new setup if I understand this correctly. Good thing you mentioned this ! 😅

SumPower

I like to use the Midnite solar combiners, then add the breakers. Good quality and never a failure when installed per instruction. 

Availalble in the NAZ store.

https://www.solar-electric.com/misomnsoarco.html

https://www.solar-electric.com/midnite-solar-mnepv20-300-1pp-breaker.html

Mr.Cockburn

Agreed! This is how I set-up the whole system way back in 2011 or so. No regrets and rock solid as you mention 👌