Multiplus 12/3000/120-50 FW 486
With inductive loads (microwave, dehumidifier) the Multiplus makes odd noises – as in the attached movie.
On checking the AC waveform, correlated to the sound there is a very large glitch in the output. That glitch is 127V peak to peak!
I have run these loads with my other inverters (Xantrex ProWatt SW 2000 and another Hardware-Store Pure Sine Inverter) and there is no glitch present. The loads work just fine. (All inverters are connected to the same bus-bar, which is connected to a 2000 Ah battery bank. The DC side is very clean.)
In trying to sort out this situation with my local dealer, we tried two other Multiplus units. The second unit produced the glitch when the loads were started up, but then seemed to “calm down” and the sound and the glitch went away and everything worked fine.
The third unit that was tried was similar to the first, but still produced the sound and the glitch. So there are definitely differences between units. This also shows that it’s not the loads that are the problem, it’s how the Multiplus deals with them. If the loads were chopping the AC in some manner, that would show up with the other inverters, and would have shown up with the second Multiplus that was tried.
Why do I care? Well, the sound is very irritating (and from the forums, it seems others are upset by the various sounds the unit makes.) Also, one of the main selling points of a pure sine inverter is that “sensitive electronic devices” won’t be damaged by distorted output waveforms. I certainly don’t want to have other devices running at the same time as something inductive.
Since there does not seem to be a technical contract at Victron that can help with this, I’m a little lost as to the next step. Comments?
