I have an extremely detailed use case question that I used AI to help me ensure my language was verbose enough but it was immediately rejected and so instead I will ask and do the inevitable days of back and forth with all the clarifying questions needed to actually come to the answer. (Where is my sad emoji) If you can help with this question and something below makes no sense or need more information please review whole question at https://svsojourner.com/victronfullquestion.html .
The crux of my question is what happens when two Multiplus II (PMP482505300) setup in 240/120 60 hz split phase output with switch as a group turned off encounter a 120V 50 hz input on only ONE of the units? I would kindly ask people not to guess as the manuals already are unclear. Looking for someone who has done it or is willing to bench test it and be sure.
Tagging @OGPS and @tonic (sorry for the direct ping) but your posts show you have done something very similar and may know the answer.
Thank you very much anyone who can assist!
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
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Whew, this is a looooong post. Sorry, but I didn’t make it past the first two paragraphs. Have you run your plans and questions by whomever you plan to purchase the equipment from?
Thanks Ed. Sorry about that. My dealer is the one who appears not to have ordered the correct MP2s to start with so I can confirm they do not know the answer to this question. I shortened my question a bunch so perhaps that helps?
I can’t answer your question directly but I can suggest, in the absence of a suitable reply, that you ask the regional Victron manager as a plan B. Their details are on the contact us page of the corporate site.
Update - Victron dealers contacted have no idea on this and were no help. HOWEVER…
Update for those who might be facing same thing designing a worldwide power capable boat. Prior to January 2026 part number PMP482505300 did not exist and the part number PMP482505110 was indeed 50 and 60hz capable. After that time they made PMP482505110 60hz only and you need to order the PMP482505300 to get 50 and 60hz capability after that. Extraordinarily confusing and not documented at all in the public sphere. Also if you have PMP482505110 and there is no checkbox for “allow wide frequency” then you must update your firmware as many versions of firmware exist which incorrectly remove this option even though the unit is capable of it. Lastly on the behavior one can expect if they either a pre Jan 2026 PMP482505110 or a PMP482505300 is as follows:
Setup for 240/120V 60hz split phase output with “switch as a group” turned off and apply 120V 50hz to input of L2 inverter - no functionality - it will show the input but does nothing with it.
Setup as in #1 but apply 120V 50hz to L1 input - both units immediately switch all output to 240/120v 50hz split phase and the charger function operates as normal. This can be extremely dangerous as you can blow up your non 50hz capable equipment. HOWEVER… more stuff than you might think works on 50 hz with no damage. In the end this is the configuration we choose to use, even with the limitations, because they are so small. If heading into Euro-power port we turn off breaker to washing machine and unplug kitchen outlet power cord (microwave, blender, hot plate, toaster, coffee maker). All the HVACs, chargers, TV and misc AC stuff around the boat works fine at 50hz. When we want to cook we flip shore power breaker OFF and the inverters switch to 60hz so fast the HVAC units don’t even shut down. Then we plug in power cord to kitchen appliances and do our cooking. Eventually when we are somewhere it would be easy to source replacement kitchen items I will try these and see if they work at 50hz as they may well but I wasn’t willing to risk it today.
The other option would be to unplug the VE bus cable, upload a new program to each inverter so they operate as standalone units, and ensure the 240v dive compressor is never turned on in this configuration. That would allow two separate 120V legs using shore power, one at 50hz and one at 60hz. I could not find a way to get this output without doing this and it is more trouble than it is worth as option #2 works so easily.