Sizing a Circuit Breaker

[bajajoaquin]

I used the 400w blueprint on Will’s site for my own camper (I'm having a hard time inserting links without them all going to the beginning of my post). Based on this, I'm basically following it on my friend's camper. However, he has a smaller camper, a Lance truck camper, and the space fits 2 200w panels better. We chose 24v Rich panels (in parallel) to take advantage of better efficiency at higher voltage. It also meant that we could save money by getting a 20 amp SCC.

Here's where my question lies: the blueprint says, "If you use the recommended 40 amp solar charge controller, you will need to install this 50 amp circuit breaker between the solar charge controller and the battery, on the positive wire." What circuit breaker would I use for a 20a controller? 25a? 30a?

Thank you!

 

[Rednecktek]

The rule of thumb is 20% overhead and round. So a 20a SCC * 1.2 = 24a, but since nobody makes a 24a breaker you can go to a 25 and be just fine.

 

[bajajoaquin]

Thanks!