Hello you all, hope you are well.
My question is , as three phase victron inverter setup doesn’t run delta, can I run it using a VFD. As a VFD would rectify it first and then creates it’s own three phase output.
My idea is running a big 220V MP2 8000va and run that top the single phase input of a VFD. OR run three MP2 5000’s or 3000’s and run those to the phase inputs of the VFD. You see this VFD can do both and create a 3 phase output either way.
Best regards, Roel
The VFD option should work, I’ve used one multiple times to run a (small) three phase motor on a single phase power supply.
Above 2-3kW of electric motor power I’d go for a VFD with 3 phase input instead of single phase.
Thanks, it’s a 4980 watts three phase motor. (max 18A per phase) So would 3x 3000VA work? I would also be setting the VFD to softstart.
It cant connect to deltaon the grid side.
But it can run a delta load.
What voltages are we talking about here ?
Normally every 3 phase motor can be wired in star or in delta, it just depends on the voltage it expects on the windings.
With a VFD softstart you’ll have the advantage of not having the 6x In inrush current at start and also a near perfect cos phi.
But it’s always a good thing to overdimension the Multis when powering electric motors.
Thanks. 240V is the max motor voltage. I get the over dimensioning , i’m using a 7.5Kw VFD to run the 5kw motor.
3x 3000VA is 9000Va so the inverter side is also over-dimensioned to power the VFD. Or would 3x 5000VA be even better although the softstart is already lowering the in-rush current.
Thanks.
Thanks for your response. In the latest victron energy video " Victron Energy Tech Talk Episode 12 Convert Android tablet to GX Touch display" Johannes Boonstra says that in inverter mode it would be draining the battery. He says the opposite, that while grid connected it’s not a problem. A bit confusing. Now the grid side is not relevant to me as it’s offgrid. I guess if I just keep the load equal on every phase by just running the motor only, it should be fine. Especially with a VFD in between.
Where does the power come from? Expected if there is no grid obviously from your battery unless your solar covers the wattage needed. The same as any other load on an inverter system that is not connected to grid.
The delta load is fine whether grid connected or inverting, if your system is able to run it (appropriately sized etc)
Thanks, I don’t know where Johannes got it from. He says it verbatim in the video. I think he means ‘fighting’ any inbalance between the phases costs energy. In an offgrid system that would come out of the battery. In a house install you would be switching between running battery and/or grid depending on the configuration of your ESS. Now in a home install with ESS the loads will always be somewhat unbalanced even if they did a good job balancing it. It depends on what loads the user has turned on or off at any given time. But my setup would be running the motor only, so it should not be an issue.
The question is to do with a delta grid in a three phase set up.
The simple answer is it cannot because there is no neutral to balance out the phases.
With a three phase motor there is no need for a neutral as the load will be balanced. This is completely different to installing the inverter system with no neutral.
So to run a delta load, to be clear, the system should be installed with a common neutral as shown in the manuals.
Thanks
