PWM fuse size help

All my controllers are MPPT and I'm familiar with them. My son ordered a 400 watt solar kit with a pwm controller and I have never used one. I assume the panels will be all parallel in hook up. I'm not sure if he is getting a 30 amp or 60 amp controller yet. All I have laying around is 40 amp fuses for the controller to the battery. Should I get a 30 or 60 amp fuse to match the output of a PWM controller? Also the panels are 100 watts each at 5 amps so I'm assuming a 15 to 20 amp fuse from the panels to the controller? Maybe I'll just give him one of my spare MPPT 40 amp controllers! lol

Minimoose said:

Should I get a 30 or 60 amp fuse to match the output of a PWM controller?

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The fuse in the controller feed to the battery is to prevent excess battery energy causing damage/fire to the cable and controller, if a cable or controller fault occurs. The 400 watt solar via a PWM is 20 amps max into 12v system. Fuse 25 or 30 amps at the battery end of the cable , awg8 cable.
Panel fuse, 10 amps in series with each panel. A fault in one panel/cable could result the the 3 'good' panels dumping power into the fault.

mikefitz said:

The fuse in the controller feed to the battery is to prevent excess battery energy causing damage/fire to the cable and controller, if a cable or controller fault occurs. The 400 watt solar via a PWM is 20 amps max into 12v system. Fuse 25 or 30 amps at the battery end of the cable , awg8 cable.
Panel fuse, 10 amps in series with each panel. A fault in one panel/cable could result the the 3 'good' panels dumping power into the fault.

Click to expand...

Thanks for the clarification.

mikefitz said:

The fuse in the controller feed to the battery is to prevent excess battery energy causing damage/fire to the cable and controller, if a cable or controller fault occurs. The 400 watt solar via a PWM is 20 amps max into 12v system. Fuse 25 or 30 amps at the battery end of the cable , awg8 cable.
Panel fuse, 10 amps in series with each panel. A fault in one panel/cable could result the the 3 'good' panels dumping power into the fault.

Click to expand...

After what you told me I decided to give him my spare 40 amp mppt and just replace it. That way the fuses will be correct and he will get better charging amps and have bluetooth. Thanks again!