I recently re-did my system yet again to make more power. I now have (3) Victron Multiplus 24/3000/70 in parallel. That went smoothly and everything is running well.
My question is how to hook up my generator for charging. I have only a small Honda 2000 watt generator that I use sparingly in the winter and each multiplus can charge 70 amps, so I only really need to have one multiplus charging to use all my generator can supply.
My question is can I just connect my generator up to one of the multiplusâ and just use one for a charger or do I need to wire the generator input to all three multiplusâ at one time? Any help appreciated.
I believe it should work if you untick the box in VE Bus System Configurator that says âSwitch as groupâ. I am assuming that you only use the generator and no other grid connectionâŠ
I have experience with this type of setup in three phase systems, but not parallel. So you might have to experiment a bit, and the configuration might not allow that. It seems that you would need to connect to the master inverter in any case.
Actually, looking at demo mode in VE Bus System Configurator, it seems you can set each multi as a separate input. Unfortunately, I canât try it on a physical system.
I went to VE Bus System Configurator and looked for âSwitch as group" but I couldnât find it. I know when I had 2 multiâs in split phase, that option was there in VE System Configurator. Maybe its not there in parallel configuration?
âswitch as groupâ is a feature of split/3 phase and not parallel systems. In parallel systems the input must be connected to ALL inverters in the parallel configuration. The only way you are going to be able to use a 2k generator in your system is either by powering a stand alone charger, or enabling ESS so that the ac input limit can be lowered enough for the generator. Using ESS opens another can of worms depending on your local regs and requirements.
Thanks for the info. I havenât used ESS and when I just looked into it, it said it shouldnât be used for off-grid systems. I am off grid. Anybody have any ideas without having to buy a new charger?
AC input limit has minimum setting requirements regardless of single/parallel/multi phase configuration. In the case of the OP the minimum setting for his parallel setup far exceeds the capability of the generator.
Although technically not supported or suggested for off-grid use, ESS has been used in many âoutside the boxâ configurations for various reasons. If all necessary precautions are taken and the system setup appropriately, it would enable a smaller generator to be used in a larger system such as this. I have had a few systems that have been temporary configured as such in order to utilize smaller backup generators while awaiting repairs to the permanent genset.
One of the main issues with using ESS in mobile or off grid situations is the potential for electrocution. ESS systems are designed to feed energy to the grid, even if feedin is disabled there is still a potential for electricity to be present on any connections/plug/bare wires etc upstream of the inverter. This is the primary thing that needs to be addressed. There are backfeed relays specifically designed for this purpose. I believe that the multiplus 2 has dual input relays, but as stated before, there is still a potential for power to be on the input terminals for a short period of time when switching is taking place.
As to your second question⊠parallel inverters act as a single unit. They expect to see ac input on all parallel connected devices. If you connected the generator to only one device, it simply wonât do anything at all.
As you are in DIY, you can hook up Flatpack 2 programmable 48V power Duplo Unit to the Honda and Chargers directly.
The PSU can be programmed to the appropriate voltage e.g. 55.2 Volt and limited in current, e.g. 35A.
You will find PSU, adapter boats in the bay and projects for CAN bus on GitHub.
Is this AC limit I see referrenced under âshore limitâ in VE Config? When I go into VE config and use this program under fake target, it looks like I can set the AC input current limit to anything between 1-50 amps. Is there another input limit that I am missing that is for generator?
For my Toy hauler I have a small propane generator (900W) to charge my batteries when I donât want to use the larger 5K Gasoline Onan which is much noisier. I have a charging cable that I fed into the Lynx on the Distributor side so the amps put into the batteries is recorded. The charger I use is a Victron 120V to 24V 8-16 amp, Hope this helps.
Thanks for recommendation of charger. I have a large battery and 16amps isnât going to do much for meâŠ
I programmed my 3 multiâs today and VE direct allowed me to put in 4.5a max AC input for all three inverters. My batteries were already full today, but will try generator tomorrow and see what happens. I think its possible Victron updated the software to allow lower limits for AC input and folks just arenât aware at this point. Anybody know if that might be true?
I cant get my head around the maths. At 110V I get 18A and half that at 220V.
MP Power factor will be close to 1, but maybe aim for a total load of 1800VA
Iâm off grid with 2 Multiplus in parallel and have an underpowered Honda Generator (3kVA). I donât use ESS.
In VE Configure I have ac input current split between the two multipluses so that the total current equals the input current limit set in the multiplus section of my Color GX.
