Hi ! Iam planning a solar pannel ( Solarfam SZ-150-MBC 150w mono 12v ) and a victronsmart solar MPPT 100/20, I have a "Fuse holder 6-way mega fuse" but I could not find a 25A mega fuse, so I have a fuse holder but wire gauge is 12awg, Im using 10awg wire gauge from solar pannel to mppt, it will be ok or should I get 12awg fuse holder? Thank you for your time. 
I would not use a fuse on the solar module's input. The solar modul is able to withstand a short circuit, and the 10AWG cable is able to carry this current permanently. So there is no need to fuse this side.
Fusing isn't just good practice, it is often required by regulations.
Relying solely on the panel for safety in the event of a serious failure is a bad idea.
If i googled that correctly, then the panel has 25,35 Voc and 7,51 Isc, means a 10A fuse would be enough and that in turn would mean the 12AWG fuseholder should be good enough as well.
If you plan on installing multiple panels in parallel, then that might be different (currents add together in paralleled strings)
Theres also inline MC4 fuse holders, those come in handy when you do want to use paralled strings but use a fuse for each string
Hello, thank you for your time to reply;
I have already anderson plugs (SB50 600v 50A) , so maybe I can add a circuit braker at near store they have "Geti GF-J01" 500V DC 16A ?
Yeah, and we all know how logical some regulations are...
But to be very precise then, this cable should be fused on both sides, close to the panel and close to the MPPT.
As the panel is a source, you have to fuse it to protect the cables. But we all know that a 10A fuse will never release with a Isc of ~7,5A.
And the second scenario is, that a failure in the MPPT will pass through the battery voltage to the panel, then you need a second fuse next to the MPPT to again protect the wires from catching fire.
But then again the question is, how much current can really be pushed from the MPPT into the panel?!
So you see, you can do it compliant to regulations, but this is not always useful and sometimes it does not make sense at all. ;-)
I think, with a 10A next to the MPPT you could solve this dilemma. ;-)
