Mutliplus II 5000 sounds like a vacuum cleaner

My Multiplus fan (?) is noisy between 2200–2400 watt inverter or charger power. It’s not the airflow that I hear, but its more like whining.

The Multiplus is in a separated tech room on the attic with closed door and I hear the whining in our bedroom on the first floor and woke me at 4 am (dishwasher was drying dishes at 2200 watt) so it is pretty loud.

When I draw 3000 watt or more the whining is gone and I only hear the airflow.

When I draw less than 2000 watt I don’t hear anything in our bedroom (except for the transformer hum).

I think it’s some resonance of the fan because it takes a while before the whining starts.

For now I limit the inverter (and charger) power to 2000 watt during the night to prevent waking up from the noise, although it discharged once at 4000 watt during the night but we didn’t wake up because there was no whining.

Is this normal behaviour?

I also saw a silent fan assistent which disables the fan on an external contact, can I also disable and enable the fan using mqtt/nodered?

And also, does anyone have the STL file for printing the external fan shroud mentioned here MultiPlus-II 48/5000/70-48 fan noise fixed (for me) without loss of warranty (external fan shroud) - VictronEnergy ?

There is also this one.

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Here is a video of the whining sound, it’s this normal?

Pretty much. Depends on load. How and where it is mounted can affect it.

Is this the fan I hear or something else like coil or other electronics?

That’s the fan.
My own parallel set, two units use of the fan is completely different under same loads.
Seems to be load related and affected by how you mount it.
Ours are all on thick brick walls. Hollow walls amplify the problem.
Considering most installs are in garages or dedicated external bricked rooms, the noise doesn’t matter in our use cases.

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We don’t have a garage unfortunately, only a wooden storage which is humid and cold so but the ideal place for electronics and lifepo4.

The multiplus is mounted on a brick wall and I’m going to place dampers between the wall and the victron.

But I’m curious if I can cancel this whining sound with a ventilator attachment like @lxonline mentioned.

If that’s the case, I let it print this week, but the whining van maybe be the fan but maybe also some harmonics in the transformer windings.

So is the fan making this whining noise or something else?

The fan will always do that, I don’t think adding more fans will change the internal fan behaviour which is driven by load as one of the variables.
Disabling the fan will have other performance consequences even with external ones.
There are many topics here and in the archive from users applying various methods to dampen noise.

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Humid and cold together is dangerous, you might get condensation and then oxidation in your multiplus.

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That’s why it’s placed on the attic, dry and around 19 degrees at the moment. That’s also why a low noiselevel is important especially during the night.

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The fan probably needs a drop of oil

The multiplus is brand new…

Rma it

Thats what warranty is for, you can always have a faulty component turning up.

Fans don’t get oiled, and the sound is not uncommon, though undesired in this instance.
You are welcome to send it for testing, though I would be surprised if any further action resulted.
Depending on use and location, and noise sensitivity, there are often complaints, but equally there are vast numbers of these installed and no one notices.
The RS is probably a better choice for lower noise, presuming it is capable of meeting the requirements and local certification.

I would have taken the RS without any doubt if it could export to grid for selling pv power at high tariff rate.

Unfortunately it can’t (at the moment?)

■■■■, i oiled mine 3 weeks ago…

We also did oil fans at a factory for point of sales computers but these where not ball bearing. Afaik sleeve bearing fans do need oil but I don’t know if this is also for ball bearing fans. I hope victron as a premium brand uses ball bearing fans and not cheap sleeve bearing fans…

@jeroenst I am guessing you will have seen this post: MultiPlus II - toroidal transformer humming

Welcome to the club. Perhaps we need some T-shirts printing.

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Hmmz, not so good…

Thanx

I have the same problem too. in my case about 2.000W it starts to sound high