This may be a stupid question

[Packen]

This is probably a stupid question to those who know but I am trying to learn.
In a previous post I made, the concern about AFCI came up. So the more I looked into that, the more I think I need protection because my panels will be on my roof.
So my question is,
Why couldn’t I just put an mc4 inline fuse on each panel? Wouldn’t an arc cause the fuse to blow and disconnect it from the other panels and isolate from the rest of my array?
Like I said, maybe a stupid question to those in the know, so please go easy on me
Thanks

 

[Packen]

This is probably a stupid question to those who know but I am trying to learn.
In a previous post I made, the concern about AFCI came up. So the more I looked into that, the more I think I need protection because my panels will be on my roof.
So my question is,
Why couldn’t I just put an mc4 inline fuse on each panel? Wouldn’t an arc cause the fuse to blow and disconnect it from the other panels and isolate from the rest of my array?
Like I said, maybe a stupid question to those in the know, so please go easy on me
Thanks

Maybe not such a stupid question after all. So what do you think? Will it work?
I still plan to go with Tigo for my rapid shutdown, just want to figure out the arc fault protection too.
Thanks
Any input will be helpful. You guy and gals are great.

 

[saenns]

It's a good q. I suspect the problem is that there can be arcing at normal operating current s.t. the fuse would not open the circuit.

 

[SparkyJJO]

It's a good q. I suspect the problem is that there can be arcing at normal operating current s.t. the fuse would not open the circuit.

This.

I've seen arc damage that a fuse (or regular breaker) won't blow from because it was neither a short nor an over-current condition.

That being said, for AC branch circuits I have mixed feelings about AFCI breakers simply because of various issues they've had (and cost). For DC though I'm more for it, simply because a DC arc can be more dangerous because it is more likely to occur and far less likely to self extingush than AC, and I don't think nuisance tripping of arc fault protection on DC is near so common.