Fuses in a Solar Panel circuit

[LadyInBed]

I have a twin battery solar reg.
Do I fuse the cable from:

• Reg to Panel (one fuse)
• Reg to Battery banks (so two fuses)
• or both the above (three fuses)?

All opinions welcome

 

[Aurai]

This short article, sort of answers your question. 3 Fuses ideal, but keep unused runs short and well protected And you can then omit fuses.

Fusing Guide | 12 Volt Planet

 

[VicS]

I have a twin battery solar reg.
Do I fuse the cable from:

• Reg to Panel (one fuse)
• Reg to Battery banks (so two fuses)
• or both the above (three fuses)?

All opinions welcome

Option 2 ........ between the regulator and the battery banks, as close to the batteries as reasonably possible. To protect the wiring from the high current that a battery could supply in the event of a fault.
The connections should be kept short anyway , so what Aurai says may be applicable.

There is a situation with multiple panel arrays where the panels themselves should be fused but its not applicable here.

 

[William_H]

The only source of high current that can melt wiring (start fire) is the battery or batteries. The controller itself should stop any high current from the battery damaging controller or wiring towards the panel. There for the risk is that the wire pos can touch the negative wire or engine etc so over current and over heating the wire. Is that a risk? depends on length of wire and where it runs and how well it is secured and distanced from and negative wire. On this basis if you do go for fuses controller to battery the fuses should be very near the battery. Fuses at the controller end of the wires will not protect the wire.
Except in cases of very high power solar array the solar can not deliver enough current to melt the wiring.
My solar array at home 1500w at about 4 amps has fuses in the pos and negative line. I know one failed as fuses can do for no reason. I can only assume that the fuses are there for protection in case of lightning strike cos there are no other sources to melt the wire. (or fuse) (unless I am missing something)
ol'will