I have a Multiplus 2 charging a 1000Ah LiFePO4 battery bank.
The Multiplus changes at 120A continuously no problems when on shore power.
However if I try and do the same with my 4KW MDKBH Onan generator it struggles the charger runs, and then it trips and goes onto the inverter. After a short period of time it starts charging again and then the cycle starts again, cuts off, drops back onto the inverter, and then starts charging again.
I can cheat it slightly by dropping the charge rate to say 50A and it will charge continuously, I can then creep the current up slowly 5/10A at a time and it will eventually get up to 120A after a while, but it’s a pain that it doesn’t work from the initial startup, it seems that it needs to warm up, but a 4KW generator should be run a 3KW load without too much of an issue.
I have changed the input from shore power to generator.
Is there another setting that I need to change on either the Multiplus or the Cerbo, am I missing something???
When running the generator, have you changed the ac input current limit setting? I wouldn’t go over about 27 amp max. It’s not recommended to run any generator at 100% of rated capacity, and there will also be a derate based on ambient temperature and elevation.
I am running on 240V and the only load on the generator is the Multiplus-charging(about 12A), I will check the loadings but I would envisage it to be in 3kw mark which is about 3/4’s of the generator rating so I don’t see why this should be an issue.
Unless there is an issue with the voltage regulator not making the voltage stable enough or the throttle/governor is working properly to keep the frequency stable enough for the Multiplus 2.
I am trying to establish what is causing the issue here, if it’s the generator or a setting in the Multiplus, the fuel system on the generator has recently been overhauled, checked and re-calibrated.
Some clarification is in order. The spec I found for your generator says 115/230 single phase @50 hz. You mentioned 240v which would imply a North American 2x120 multiplus @60hz. Can you post what voltage/hz is your generator configured for, and the exact model of inverter?
If you have a 60hz inverter the lowest frequency accepted under wide input is going to be 45hz. If the generator is 50hz you may be dropping enough under sudden load to cause the disconnect. These smaller generators can have a hard time maintaining proper frequency under medium to heavy load.
Sorry for the late reply, I have been very busy over the last couple of weeks….
We are based in the UK so are set and running at 50hz not 60Hz
Yes my generator is 115/230v I am running wired up in the 230v configuration, originally it was running at 230v however I have recently increased it to 240v to try and eliminate the possibility of a voltage drop, I will return it to 230v as this is what our shore supply is.
The voltage is only set on the regulator.
Part of the Onan/Cummings sales pitch was that it was very voltage stable so I don’t think this is the issue unless I have a failing component.
My inverter is a 50hz one and is what the shore supply is.
Something is causing the Victron Multiplus 2 to cut out during charging and it will do it if I start charging at around 50/60A (50% of the charger capacity) and slowly increasing the current 10A at a time… I will eventually get to the full capacity of the charger but it may take anywhere between 30mins/1hour to allow me to increase it.