Victron inverters in parallel question

[Dockhead]

However, I see one problem for my particular case -- the 1600kva multiplus only has a 16 amp transfer switch . I have a 6.5kW generator which can put out 30 amps. Plus another 16 amps or so inverted from my 3000kVA multiplus -- 16 amps transfer switch won't cut it. The power system downstream of the Multiplus is designed for 50 amps.

[swampbush]

Originally Posted by Dockhead

However, I see one problem for my particular case -- the 1600kva multiplus only has a 16 amp transfer switch . I have a 6.5kW generator which can put out 30 amps. Plus another 16 amps or so inverted from my 3000kVA multiplus -- 16 amps transfer switch won't cut it. The power system downstream of the Multiplus is designed for 50 amps.

You could use two 3kva multilplusses with 50 amp changeover in series (cascade?) I suppose, but then maybe they should just be in parallel as master slave if they are identical.

[Dockhead]

Originally Posted by swampbush

You could use two 3kva multilplusses with 50 amp changeover in series (cascade?) I suppose, but then maybe they should just be in parallel as master slave if they are identical.

Or I could use the 2000kVA multiplus as the secondary, which has a 30 amp transfer switch, which I could probably live with.


I had originally thought about two 3000kVA multipluses set up as a gang, but since both have to be on, and since they both go down if one does, I have scratched this idea.



Have you consulted Victron about your setup? I would want to run that by them to be sure there aren't any hidden "gotchas".

[swampbush]

Originally Posted by Dockhead

Or I could use the 2000kVA multiplus as the secondary, which has a 30 amp transfer switch, which I could probably live with.


I had originally thought about two 3000kVA multipluses set up as a gang, but since both have to be on, and since they both go down if one does, I have scratched this idea.



Have you consulted Victron about your setup? I would want to run that by them to be sure there aren't any hidden "gotchas".

I haven't contacted victron, but in their forum they do say that they have done what I am doing, at least for testing. I think Catnewbee uses an inverter as supplementary power to his Quattro 5000.

[mvweebles]

Would think stacking the inverters as designed would be ideal (assuming they are capable). Granted there is no redundancy, but a single dual-inverter "bank" running at 40% would very likely be more efficient with less wear and tear than two isolated inverters that see high draw individual spikes.

[Dockhead]

Originally Posted by mvweebles

Would think stacking the inverters as designed would be ideal (assuming they are capable). Granted there is no redundancy, but a single dual-inverter "bank" running at 40% would very likely be more efficient with less wear and tear than two isolated inverters that see high draw individual spikes.

Will be much less efficient than one inverter operated and closer to max. And especially under no or little load - the 3kva multipluses have something like 20 Watts each of overhead when operating very small loads.

[mvweebles]

Originally Posted by Dockhead

Will be much less efficient than one inverter operated and closer to max. And especially under no or little load - the 3kva multipluses have something like 20 Watts each of overhead when operating very small loads.

So is design parameters for very light load or high load? I'll take your word for it that parasitic overhead draw is greater, but curious what tradeoffs are when half-load (full load for a single). Doubt inverters like running at higher load levels.

[Wild Goose]

Thanks everyone for your suggestions and ideas, gives me something to think about. Generally it’ll be pretty light loads so I think I’ll end up just having one setup for running all the time with the secondary to take the only second major draw item. With an outlet or two that will give me a backup without having to do anything too fancy. I already have 2 Phoenix 12/3000, not multiplusses as I am not planning to be on dock very often and I already have a really good dedicated charger. I was initially just going to parallel then saw that while running that the running power was 20w each, so was looking for ways to halve that unless necessary.
Thanks once again

[Adventuresail]

Hey Wildgoose, Do you happen to know if all the inverters of the Phoenix line can be run in parallel? I have a 12/1200 and would buy another if i could run them in parallel

[Dockhead]

Originally Posted by mvweebles

So is design parameters for very light load or high load? I'll take your word for it that parasitic overhead draw is greater, but curious what tradeoffs are when half-load (full load for a single). Doubt inverters like running at higher load levels.

I had to look this up to be sure, and here is what I found:



https://community.victronenergy.com/...fficiency.html



Not exactly what I expected. So you are more right than I expected -- two running at half load will actually be slightly more efficient than one running at full load.



But two running at or near idle will be terrible, which is what the OP was trying to avoid.



As to whether inverters "like" being run at higher load levels -- I don't know why they wouldn't, so long as temps are kept within parameters -- do you? What I CAN say is that Victron gear is optimistically rated, and on two levels.


My 3000/70/50 Multiplus sounds like a 3000 watt inverter, doesn't it? Guess again. 3000 is VA, not watts. So in watts that's 2400 in the BEST CASE, at 25C, downrate from there with higher temps.


Practically speaking, it's not good for continuous loads of much over about 2000 watts, but the control panel will complain if it's unhappy. I do not believe that running it at 2000 watts in a well ventilated space, with no warning lights, is harmful to it.

[Pelagic]

Like many, switching to Induction cooking and more appliances has me adding more Inverter power to my 2008 Victron Multi 24/3000/70.

My key issues are that you cannot parallel a 2nd Multi unless it is the same model and firmware. Also you are somewhat compromised by your existing distribution panel, wiring and space available, especially on an older boat like mine, that was never designed for so much AC electrics.

In my case, I chose to forego the Power Boost function in 2008 and stay with my AC Panel's supply lockout system of Shore/Gen/Inverter. Have never needed or missed it and the Multi 3000 has worked flawlessly, even though it has operated in the Tropics.

So when adding additional inverter power, I decided to order the Victron Multiplus 24/5000/120 and other components to make the upgrade Lithium ready.

Victron gear will not arrive until late August, so I am still working thru the details of the installation and distribution, but here are my thoughts:

1. The new Victron 5000 Inverter will be my primary AC supply to Galley and Hot Water
2. Generator as Backup for Charging, running Aircons and Shore supply for the same heavy loads at the odd Marina or Drydock
3. The Main Panel with Lockout Supply could have those Heavy loads connected to V5000 where present V3000 is installed.
4. The V5000/120a would take over the primary house bank charging if we needed to run Gen at anchor during the rainy season
5. FYI, my existing Solar which runs all my 24v Fridges/Freezers/Fans/ Pumps/Lights is at 100% SOC before noon when using shore power for cooking, HW and aircon. I expect at anchor, cooking main meal at noon, House Bank will be in Absorption by 3pm. So my abundance of Solar now has made me even less attracted to Power Boost


6. The Sub Panel will be used for lighter loads to become a dedicated UPS system (computers/Monitors/ TV-Entertainment using the V3000 as it’s dedicated supply?
7. The V3000 would stay on “Inverter” Mode with a separate AC Breaker Feed to power Charger if ever needed from Gen or Shore Power?

8. My old 1991 Skyla 50a charger I will shift down to Engine Room beside 24V Starter 200Ah wet cell 8-D batteries. Normally off but serves as an emergency boost to keep that charging system separate from the new AGM’s and future House Banks?