Why fuse or circuit breaker on the feed from the solar charge controler

[larfme]

Why do people put fuses and circuit breakers between the battery and the solar charge controller? If the fuse or breaker pop, wont it burn out the charge controller as well? I can see why a manual shutoff is helpful but not the other two.

 

[John Frum]

Why do people put fuses and circuit breakers between the battery and the solar charge controller? If the fuse or breaker pop, wont it burn out the charge controller as well? I can see why a manual shutoff is helpful but not the other two.

Because the designer of the system wanted over-current protection on the circuit.
If a situation developed where the ocp tripped on a fault condition I for one would rather my solar charge controller gave up its life than my mobile house went up in flames.

BTW @Will Prowse tried killing his collection of solar charge controllers in this manner and couldn't get any of them to fail.

 

[Zwy]

Why do people put fuses and circuit breakers between the battery and the solar charge controller? If the fuse or breaker pop, wont it burn out the charge controller as well? I can see why a manual shutoff is helpful but not the other two.

It's not really about the charge controller, but rather the wiring. https://www.renogy.com/blog/how-to-fuse-your-solar-system/

Parallel array is different than series. If in parallel and you have a panel that shorts, all the amps would go to the shorted panel.

 

[Diysolar123]

Why do people put fuses and circuit breakers between the battery and the solar charge controller? If the fuse or breaker pop, wont it burn out the charge controller as well? I can see why a manual shutoff is helpful but not the other two.

you want to fuse all direct lines connected to a power source because the world is filled evil screw drivers and wrenches, that will, at the worst times...dive right between any open metal contacts and short out the source.

its the tools you see, not that people sometimes are careless, nope, its the tools trying to kill us!!
fuses are cheap protection.

 

[navillus]

Very new and getting information from Renogy stating I need a fuse between solar array and solar charge controller. If I have 3 panels 210 watts, wired in series. 9.3 amps a panel. Do I need a fuse between my panels and solar charge controller (40amp)? My panels have a Max Over-current protection rating 20? Is this the same as "Max series fuse rating?"

 

[HRTKD]

Why do people put fuses and circuit breakers between the battery and the solar charge controller? If the fuse or breaker pop, wont it burn out the charge controller as well? I can see why a manual shutoff is helpful but not the other two.

1. To protect the wire
2. To give me a way to turn off power to the charge controller should I need to work on that circuit

 

[time2roll]

Very new and getting information from Renogy stating I need a fuse between solar array and solar charge controller. If I have 3 panels 210 watts, wired in series. 9.3 amps a panel. Do I need a fuse between my panels and solar charge controller (40amp)? My panels have a Max Over-current protection rating 20? Is this the same as "Max series fuse rating?"

I would (and did) skip the fuse on a single string. I assume you are using #10 wire and you can short them all day long with no harm to the solar panels and wire will not get warm with 10 amps.

No the "Max series fuse rating" is different. This is to protect parallel connected strings from back feeding one of the strings that may have a failure such at a tree branch fell on it. So if you have 9 panels with 3 series strings in parallel they could feed 18.6 amps back into that failed string and cause issues and need a fuse. Low power systems I would not worry so much like 3 parallel panels. But when you have more in series going to 90 to 400+ volts this gets to be a real issue.