fuses and where to fuse

[wagoneer]

I have learned the hard way, burnt my Morningstar SunSaver MPPT 15 Now speaking with a friend he recommended I fuse the Negative side cause thats the way DC works. I am using a 36 volt panel 240 watt, with 2x6 volt green river batteries. Just purchased 2 x 30 amp DC in line fuses. Protecting the controller and batteries has become my cause LOL. the battery compartment is under the side entrance with easy access enough space for the controller to be included.

 

[blars]

Fuses are general designed to protect from fire by protecting the wire, not the device. They should be on the non-ground side as close to the power source as practical. Solar panels are inherently self limiting on current, so general do not need a safety fuse. (But a fuse or breaker may be a convinient way to cut off power when working on the circuit.)

Lead-Acid batteries will outgas hydrogen, so a potential ignition source such as a controller should not be in the same compartment.

 

[Spaceman Spiff]

The instructions that came with my Morningstar TriMetric specified what size and where to put the fuse.

MaineSail has a good write-up on fusing:

http://www.pbase.com/mainecruising/battery_fusing
http://www.pbase.com/mainecruising/fuse_voltage_drop

You can use a smaller fuse to protect the controller, but if the controller is sized correctly that shouldn't be an issue.

-- Spiff