Inline fuse question
- Thread starter JoeSTP
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gnubie
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- Sep 20, 2019
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Can you describe the setup of your system (or proposed system)? That rating is the maximum rating that will still permit some protection should something go wrong with the panel and current can flow back into it from another source. Depending on your setup it may not be needed or could be less than 20A.
Thank you for your help, Well I have 5-390w and I'll put 3 in series and 2- in series and 2- in parallel, I think this is how its wrote 2s2p, its a 24v system and its going on my box truck and the SCC is 60A and the Inverter is 3000w. I'm starting out with 2-Sok Lithium batteries 100ah.
gnubie
Solar Wizard
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- Sep 20, 2019
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You can't mix and match 3s with 2s2p and expect good results. If you just mean these are the two configurations you are considering, ie either 3s or 2s2p that's fine.
With the 3s configuration there's no need for a fuse unless your string of panels can provide more current than your charger can accept. If your string can produce say 5 amps and your controller can accept 10 amps, you want that full current to be available to the charger so in practice there isn't a fuse that you can use here that will give any practical protection since it will never blow.
With 2s2p there's no need for a fuse in line with the strings since you only have two. Even if one string faults it will never get more current that it can handle or produce. The fuse has to be rated to carry the full current out of the string, and since there is only one other string which produces the same current there is no circumstance in which there will be enough current to blow the fuse on the faulting string. If the array can provide more current total than the charger can accept a fuse between the array and controller is appropriate.
Hope that hasn't been confusing.
With the 3s configuration there's no need for a fuse unless your string of panels can provide more current than your charger can accept. If your string can produce say 5 amps and your controller can accept 10 amps, you want that full current to be available to the charger so in practice there isn't a fuse that you can use here that will give any practical protection since it will never blow.
With 2s2p there's no need for a fuse in line with the strings since you only have two. Even if one string faults it will never get more current that it can handle or produce. The fuse has to be rated to carry the full current out of the string, and since there is only one other string which produces the same current there is no circumstance in which there will be enough current to blow the fuse on the faulting string. If the array can provide more current total than the charger can accept a fuse between the array and controller is appropriate.
Hope that hasn't been confusing.
