Fuse/breaker sizing

Petes67bird

Hi everyone. I just pieced a small system together and need help on fuse or breaker sizes.  I purchased a hightec 200w panel. This will be fed into my 20a Mppt controller. The controller will go to a 100ah group 31 agm battery. The battery will go to a blue sea systems 12 panel blade fuse box which will be wired to my vent fan, USB hub, sockets and overhead led lights. Where do I need fuses and what size. Other than the panel and brackets, this is what I have ordered so far. Anything else I need? Thanks 

1. Battery 100ah

2. Mppt controller https://www.amazon.com/dp/B01BXRIRMQ/ref=cm_sw_r_cp_apa_i_gVt9CbAP9Z6GP

3. Mc4 cables  https://www.amazon.com/dp/B075424L8R/ref=cm_sw_r_cp_apa_i_XVt9Cb4WMANNA

4. Cable roof entry housing  https://www.amazon.com/dp/B01CSEA9KG/ref=cm_sw_r_cp_apa_i_RWt9CbKH7FFK7

5. Fuse Panel https://www.amazon.com/dp/B001P6FTHC/ref=cm_sw_r_cp_apa_i_wXt9CbPVWN1JW

6. 12v plug with USB  https://www.amazon.com/dp/B01AYOSD50/ref=cm_sw_r_cp_apa_i_gYt9CbBBP5EM5

7. Smart battery isolator https://www.amazon.com/dp/B00WTAFR84/ref=cm_sw_r_cp_apa_i_uZt9Cb3MKA1E6

Miscellaneous wiring, hardware and sealant

Estragon

I'd put a DC rated breaker between the controller and battery.  Size depends on wire, but I'd use the largest wire that physically fits on the CC output terminals, and size the breaker to whatever the controller maker recommends.

I'd also put a breaker on the wire going to the fuse panel, again sized to the wire.  Fuses could be used, but breakers make handy disconnects.

Petes67bird

Estragon said:

I'd put a DC rated breaker between the controller and battery.  Size depends on wire, but I'd use the largest wire that physically fits on the CC output terminals, and size the breaker to whatever the controller maker recommends.

I'd also put a breaker on the wire going to the fuse panel, again sized to the wire.  Fuses could be used, but breakers make handy disconnects.

Could you link me to breakers that you would use that aren't too spendy? Thanks for the advice

Estragon

These are pretty reasonable:
https://www.solar-electric.com/mnepv.html

A box to mount them.  There's also a bigger version which might be useful if you want buss bars / more room for connections:

https://www.solar-electric.com/baby-box.html