We have a solar system in our Airstream trailer installed by an AM Solar dealer. Lately after we get to our next site and hook up to shore power, there is a loud hum coming from the Victron Multiplus 12/3000/120 inverter as it works to top off the batteries. The hum only lasts for a short while and stops once the system achieves "absorption" I think.
Any ideas of what I can check and whether or not this is something serious?
Thanks
I'm getting a similar hum in a new 12/1600/70 multiplus (about 200Hz?) as absorption completes and it persists while in float with low currents (2-3 amps) into the battery so it's not actually doing anything.
There's no resonance, mine's still sitting on carpet while I test it out. Its too noisy, I'd have to disable battery charging most of the time.
Hi @sjones
You could try to lower the charge current.
Usually when a unit makes too much noise, its because it's mounted on a panel that is not rigid enough and resonates with the unit's vibrations.
Thanks Daniel. The unit is mounted to the floor of my Airstream travel trailer. The floor is quite rigid, so that is not a possibility.
How would I lower the charge current? All equipment is made by Victron.
As mentioned, the vibration/noise is only when shore power is first connected. After a few minutes it fades out.
Thanks,
Steve
Re: charge current, you'll need to use the VEConfig software with a MK2 or MK3 interface hooked into the multiplus.
Resonance issues can be solved in a number of ways - increase stiffness/weight is one method, soft mounting to "soak up" the vibration is another. Unless you have a specialist on hand to advise, imo its a case of trying different solutions until one sticks - its likely to be very dependent on the physical geometry of the mounting location, mounting orientation and how the mounting location is connected to underlying structures.
