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I have two multiplus inverters in a mobile set up in split phase that I would like to have match the power input and allow passthrough and assist. There are times when power supplied is from a single phase power source. I do not need 240 volt capabilities. Is it possible for the inverters to see the single phase and fully operate.
I think they can be configured as " do not switch as a group" then you may be able to use one of them with the supply.
you will need to use ve bus system configurator.
I do have them configured in split phase but functionality it not complete. When the inverters test the line voltage and see that the voltage of both L1 and L2 are on the same sine wave, the follower will not allow pass through current or allow the inverte to charge the bank. It will invert full time. I would like the inverters to just match the wave of the input power supplied.
Hi, thats not possible. You have to set the type during configuration, they will not auto-adapt.
One thing you could perhaps do, since you have no 240vac loads, is to split the loads and not pair those two inverters in a system.
Just let each do what it can do, individually.
Could they then be calibrated to accept the same sine wave? Because I am mobile my sources of power can change. I am predominantly off grid relying on solar and lithium so split phase does work well for those times. But I would like to maintain passthrough and charging with both units. The outputs are not wired in parallel and would not function correctly if they were and I were to plug into a split phase circuit. Doing a reconfiguration in the inverters would be easy when changing power sources. Rewireing the inverters would not be an option.
Hi, they would not need calibration to accept the A-C input sine wave.
Note that breaking their link; which is what I’m suggesting; does have some other side effects: you’d need to rewire the lithium protections, and in case you have monitoring like a DMC or CCGX, that will change as well. It’s all possible, but gets a little complicated and not very common.
From Victron we won’t be able to help in all the details with this; best option I can recommend you is to find a trained and experienced installer.
Thank you for your responses. The functionality that I am trying to obtain is actually becoming more common here in the United States with the RV community. There are many of us that are currently living full time in our RVs that bounce between complete off grid situations and partial to full hook up RV parks. Your victron products have become more popular do to the connectivity of a total package. For the most part the dual inverters wired in split phase work for most situations except when the RVs are powered by most onboard single phase generators or connected to 30 amp service. (More)
Does Victron have a list of trained installers that will be able to get the results I am looking for? So far everyone that I have made contact with has said that they have made a request to allow the full functioning of the inverters but that they did not know of a work around other then rewiring the inverters to only give functions in parallel. Because it is still only giving the ability to operate in parallel, it is not a viable solution either. How does the follower know not to turn on the passthrough relay when it is not receiving power 180 out?
I believe you can configure both of your MultiPluses in parallel and feed them only L1 when you are on a 50A 240VAC park power pole. Set the shore current limits appropriately, and you can charge and/or pass-through at up to 4800W (80% of 50A at 120VAC) total.
The number of times you would otherwise pass-through more than 4800W (which you can only do with your two Multipluses in split-phase stacking) is very small if you have a typical RV. For those rare times, the power assist can cover your momentary peak load.
Obviously, this configuration works fine for 30A, 20A, and 15A shore supplies as well.
This is what I believe is happening when in parallel. Because the outputs of the inverters are not wired in parallel, the master is being misled. If both units are powered and charging at the max output and a 1200watt load is applied on L1 (master) it will overcompensate by shutting down both chargers and carries the load until the generator is then reintroduced. If that same load is applied to L2 (slave) it appears the load is not reacted to by the inverters and the load is carried immediately by the generator. The generator output is also not capped at the maximum set on the inverters.
A typical day in the RV can vary based on location but may include running two ac units while doing a load of laundry. Some days it happens while being plugged in to 50amp service in an RV park or a 5500watt onan generator supplying single phase power at 45 amps. It could also be running one ac unit while power is being supplied by a small inverter generator that is putting out 1200-1700 watts depending on elevation. When coupled with a 1400 watt solar supply and 7.9kw of lithium batteries, it can be stretched through the hottest part of the day.
I know I'm late to the party here but I figured i would chime in since I have a very similar setup. I have a motorhome with a 50A shore connection that hooks up to 240v split phase and feeds that to two Victron inverters (5kva Quattros in my case). The Quattro's are configured to run in split phase and my Quattro's are also connected to a 6KW generator which only puts out 120v. (More on that later)
These are tied into a 48v 200 AH Lithium battery (Roughly 10 KWh)
In my case: When I connect to 120v shore power (Such as a TT-30 (30 amp) RV outlet) the adapter that converts from 50 to 30 amp simply connects the one hot leg of the 30 amp outlet to *both* legs of the motorhomes electrical input. When the Quattro's see they are getting a Sine wave that is not as they expect (They expect 180 degrees out of phase, and this gives them 0 degrees out of phase) the "master" inverter connects to the line and the "slave" inverter simply refuses to connect and continues acting as an inverter.
The only real *problem* was the generator. Sure it could work the same as being plugged into a 30 amp 120v outlet, but a single Quattro can only charge the batteries at about 4kW max (Less when they get warm). Since I have a 6kW generator it's not running most effeciently at the only 3-4kW the single Quattro would draw. In order to address this I added an Autotransformer (Victron offers one but I ended up using the Outback brand) to convert the output of the generator to 240v split phase. Now when i fire up my generator I charge my batteries at the full 6kW available from the genset.
Nice setup. Do you have 240V circuits on your rig?
If not -- and most RVs today are set up this way -- you can stack the two inverters in parallel and avoid having to buy the autotransformer.
You could use the same transformer for shorepower I'd think? saves losses from AC-DC-AC conversion (and adds a bit of standby use from the transformer)
I am not sure why it has been and continues to be recommended to permanently modify the RV to parallel the inverters. The inverters are smart enough to know when they are 180º out from each other, why can't they just be told to accept that they are on the same phase. It is not uncommon that people bounce between the two situations. But regardless, I still can not understand the reasoning to permanently limit yourself to a single leg of 50 amp service when plugged in unless you were consistently on a single phase output generator over 3000 watts. This is what my CCGX looks like when I am on a 50 amp pedestal. I do not have a large onboard generator so it doesn't matter as much to me in the grand scheme because the way it is now, it all works out for the better. Obviously we are just small fish in the Big Victron pond. But if anyone hears of a hack, please let me know.
I am in progress of installing a similar system to my 50A motorhome, but using 2 48V 3000VA Quattros and have a 7.5 KW Onan - which is wired two hot two neutrals plus one ground through a double pole 35A breaker, originially this went through a transfer swich and I am rewiring to go direct to the inverters AC 1 inputs. As per this discussion this means I only will get 1/2 of the generator output available... I was wondering how you wired up your Outback autotransformer...i.e. did you just wire one of the generator legs and then only connect the transformer output that is now 180 degrees out of phase to the AC 1 input on the second Quattro? I assume this will be limited by the autotransformers neutral phase continuous current limit - about 30A so should be ok for me. Regards Colin
