I have a lifepo4 battery which has an internal fuse of 200A combined with an 200A JK BMS. i want to connect 2 multiplus 3000/48/35 in parallel. Is it allowed to connect them without extra (energy dissipating) fuses?
You cannot run a single wire to both Multiplus. You must run separate wires to each one. Therefore, each wire - and each Multiplus - needs it’s own fuse.
I can run multiple 35mm2 wires from the battery terminals parallel to the multiplus inverters. The cable can withstand the 200amp current or even more in case of a failure.
The 200amp/20kA fuse already dissipates 18 watts at 200 amp. Adding more will make the dissipation 36 watt at 200 amp.
It could be more like 100 amps. the Multiplus 2 3000/48 can deliver 5500 watt for a short period of time. A 35mm2 cable can handle that, but a 70mm2 will have less dissipation. Although in normal operation a 35mm2 cable would be fine up to 3000 watt. But I could also wire the system with 70mm2 instead.
The wiring isn’t the problem, but Victron recommends a 125 amp fuse for the Multiplus 2 3000/48 but they don’t demand it. So in certain circumstances an other fuse than recommended could be allowed, but I didn’t find any specification of this.