timothygange
New Member
Hoping for some electrician knowledge here!
I'm working on a self-build project which will have 340W of solar from 2x 170W panels (to be wired in parallel). I'm using an Ablemail AMS 12-12-30 charger which can deliver 30A and takes input from either the solar panels or the alternator when the van is running.
I've read in a few places that you should protect all cables and have seen schematics with MCBs (or fuses) just about everywhere. However, after some more reading, I don't see how to protect solar cables.
The panels I bought have a current at Pmax of 9.5A and a short circuit current of 9.93A. Even if I could find a 9.7A fuse, it would presumably take a long time to trip at 9.93A (hence bad at protecting) and running it at 9.5A for days on end would presumably cause it to fail very prematurely (pain in the backside). Also, to keep voltage drop low, I'm going to be using 6mm cable after the T-junction, which is rated for 50A. That's well above the ~20A combined from the panels so the panels can't damage the cable anyway. What does make me nervous about this is if there is an insulation fault in the cable (let's say a squirrel gnaws on my cable) then whilst the cable itself wouldn't overheat, the panels would presumably have enough power to cause some serious arcing/welding which would be a big fire risk. I can't see any way to protect against that other than careful cable routing / conduit.
Thoughts and suggestions welcome!
Thanks,
Tim
I'm working on a self-build project which will have 340W of solar from 2x 170W panels (to be wired in parallel). I'm using an Ablemail AMS 12-12-30 charger which can deliver 30A and takes input from either the solar panels or the alternator when the van is running.
I've read in a few places that you should protect all cables and have seen schematics with MCBs (or fuses) just about everywhere. However, after some more reading, I don't see how to protect solar cables.
The panels I bought have a current at Pmax of 9.5A and a short circuit current of 9.93A. Even if I could find a 9.7A fuse, it would presumably take a long time to trip at 9.93A (hence bad at protecting) and running it at 9.5A for days on end would presumably cause it to fail very prematurely (pain in the backside). Also, to keep voltage drop low, I'm going to be using 6mm cable after the T-junction, which is rated for 50A. That's well above the ~20A combined from the panels so the panels can't damage the cable anyway. What does make me nervous about this is if there is an insulation fault in the cable (let's say a squirrel gnaws on my cable) then whilst the cable itself wouldn't overheat, the panels would presumably have enough power to cause some serious arcing/welding which would be a big fire risk. I can't see any way to protect against that other than careful cable routing / conduit.
Thoughts and suggestions welcome!
Thanks,
Tim
