Solar Panel Fuse

[noelex 77]

I installed 330W of solar panels recently. I have hooked up some temporary wiring, but now I am doing the job properly. I have some tinned 35mm square (AWG 2) cable and am planning the electrical installation.
The wiring will be lead back to the service battery with its own battery switch I was originally planning 30A circuit breakers or fuses in the system, but the options for fuse holders that will sensibly take 35 mm squared cable is limited. I could get a 40 amp ANL fuse, but it would need to be ordered from overseas.
I already have a 100 amp ANL fuse protecting the service battery circuit (the panels will charge service only) and I am considering using this existing fuse as the only protection in the solar panel wiring.
Adding the complexity of another fuse holder in the battery box with the attendant voltage drop, risk of poor connections and cost seems to be of limited value.
I would be grateful for a second opinion.

[CharlieJ]

Every B+ conductor on the boat, with the exception of the starting circuit, should be protected by a properly sized over current protection device (OCPD: fuse or circuit breaker) with an appropriate ampere interrupt capacity (AIC).

[sailvayu]

I am guessing you are using the #2 to avoid voltage drop as you do not state run length. I think I would install a electrical enclosure box as close to the batteries as possible. In the box I would install 2 buss bars and connect your #2 wire to that from there connect #8 wire to a 30 amp Airpax type trip free switch/breaker mounted on the lid or side. You would no longer need a separate on off switch as your could use the breaker to turn off the circuit. Would not see any real voltage drop in the very short #8 wire run from the bus bars to the back of the breaker. Clean and simple don't forget the label, pet peeve of mine no label on breakers and switches.

Good luck