4.2. Battery
The battery supply must be protected by a fuse as per below table. This is also the case even if the solar charger has already been been equipped with an external fuse.
The above paragraph could be made a little clearer, maybe it's got a twist of google translate in there.
- Regarding the MPPT 100/20 48V is this relevant as the unit has a 25A ato fuse fitted from the factory?
- I presume Victron is talking about the solar charger already having a fuse is refering to the PV side of the MPPT?
- Is this to prevent a battery short fault discharging back into the MPPT in which case the pre +bus bar fusing should prevent if correctly fused (AIC) close to the battery or
- to protect the cable from the battery to the MPPT?
- Where do the 25A and 30A recomendations come from?
- I presume a DP 15kA 40A MCB type Z non-polarity close to the MPPT would suffice as a means of isolation from the battery as per regs if using 30cm of 6mm² cable between the 30A fuse at busbar+ and MCB next to MPPT?
PV>16A MCB>MPPT 100/20-48(25A fuse onboard)>40A MCB>6mm² cable>30A fuse at busbar
Looking at this paragraph again, I presume it means that you have already fused the PV input side externally.
Then the ato fuse that is built into the MPPT prevents the PV Voltage/current fault from crossing over to the charging side.
Then I guess that leaves you with the fuse or MCB needed to protect the cable on the charging side to the battery.
I reckon that's what they mean.
regards
