Assume a multiplus 3000 12/3000/120 with an inverter specification of 6000 watts AC peak power connected to a fully charged 400 amp hour 12 VDC lithium battery bank. The battery and multiplus connecting cables are 4/0 welding cable with 2062/30 stranding and the cable length is 3 feet. Given a 120 vac 6000 watt peak load event what would be the expected peak 12 vdc input current?
Victron recommends fusing the multiplus operated at 12 vdc with a 400 amp fuse. The multiplus has a published inverter efficiency specification of 93%. If the 6000 peak watts of AC output specification is true and given an inverter efficiency of 93% my calculations indicate a 400 amp fuse is under the momentary peak DC input current. Does anyone know in actual practice what is the highest possible peak 12 vdc DC input current drawn from the battery bank by the multiplus inverter?
When might such an event happen? Assume the AC input current limit of the multi 12/3000 is set to 20 amps and the multi is being supplied 120 vac shore power. The multi is supplying a 4400 watt AC load and configured for power assist and actively operating in power assist mode. An additional 1600 watts of AC load is then energized. Shore power drops off line when the additional 1600 watt load comes on line and the multi attempts to supply 100% of the 6000 watts AC load. Will the 400 amp fuse between the battery bank and the multi handle the momentary DC load until the multi software turns off the inverter?
