Since about a week now I have a three phase DESS system with 30kWh of batteries and three multiplus 48V 5000VA units running. Overall I’m very happy with the setup and DESS is working well!
I do see one point of possible improvement though: We have two electric cars that will also try and charge at the cheapest possible hours, i.e. simultaneously with the Victron system so I have enablet peak shaving at 24 amps in order for the victron system to not overload the main breakers. This is working well, but… One of the cars is a single phase car that only charges on phase 1 and draws maximum power doing so. Thus, while charging this car (an Opel Corsa) the victron system cannot draw any power on L1. It does still charge on L2 and L3 as I would expect. But: the Multiplus units can draw a maximum of 16Amps AC (breaker limit), they are limited on the DC side by my battery to charging at approximately 7,5kW (150A DC), thit equates to approximately 12 amps 230V AC for each unit when three phases are charging.
What I don’t understand is this: If L1 is not able to provide power for the battery, then why are the units on L2 and L3 not up regulating to the maximum power of 16 amps AC, outputting approx 2*3600=7200W to the battery? What I’m seeing is nothing on L1 and only 12amps AC on L2 and L3.
Just for clarity, my setup:
- 3 phase multiplus II 48V 5000VA units behind a 16 amp AC breaker
- main breaker for the house is 25 amps
- While charging the Opel Corsa draws maximum power on L1
- The battery system is limited to 150 amps DC, approx 7,5kW while charging
- The multiplus units on L2 and L3 stay at approx 12 amps AC while charging the battery even though they could go up to 16 amps per phase.