question

John avatar image
John asked

Loud noise and vibration from 5kva Quattro only when powering a specific load

One of my customers is having an issue I'm unable to fix, where the Quattro makes a very loud and uncomfortable noise but only when running a Brava oven. This noise is also noticeable as physical vibration on the AC wires, and transfers an audible noise to other components on the same circuit even if they're switched off (the induction cooktop would hum at a similar frequency). The Multiplus makes the same noise with that oven, but I don't know for sure if the noise transferred in that setup. Since I've isolated the issue as only occurring with the Brava and Victron inverters, I'm thinking it's not simply an issue with one or the other but an issue with how they interact.

The oven is only around 1500W, which is well within what either inverter can supply, and this problem doesn't occur on other brands of inverter with this oven (we've tested with Cotek and it runs perfectly fine). I've verified all connections are secure, the problem persists through any settings changes I thought might affect it, and the inverter should be on the latest firmware (which I can verify if needed). Wire is sized larger than required to supply the load too, so there's no obvious supply or delivery bottleneck. Readings from the app track with that, both AC and DC voltage are what I'd expect when under load and neither dips to any significant degree.

I don't think it's a fan issue or anything mechanical, by holding a strong magnet near the wire I could feel the same vibration without physical contact which implies to me it's electrical. My best guess is it's some sort of harmonic interaction between the Victron inverters and the Brava, but I'm at a total loss as to what to do about it. My experience is mostly in DC power so maybe I'm just overlooking something, power factor issues perhaps? Anyone have any ideas? I'm happy to provide additional information or clarification, I've been working with Victron components for years and I don't think I've ever been this stumped so I'd love to understand what's happening even if there isn't a fix.

Thank you for your time,

John.

MultiPlus Quattro Inverter Charger
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

5 Answers
Kevin Windrem avatar image
Kevin Windrem answered ·

Some heating devices switch the load on and off rapidly to regulate temperature. This current pulsing can cause the type of noise I think you are describing. Some heating devices that have a high and low setting insert a diode in series with the heating element on the low setting. In this case, current flows only on one half if the sine wave. This too causes nasty noises. My espresso maker cycles the heating element several times a second and drives the inverter nuts.

Several have reported this type of behavior but no one has reported any failures resulting form them

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

shea avatar image
shea answered ·

Sounds like back EMF due to the oven's circuitry, triacs etc. Probably easier to find a compatible oven than replace the Quattro.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Rob Duthie avatar image
Rob Duthie answered ·

This happens to all of the Multiplus and Quattro range of inverters.

It doesnt cause any harm just the noise thats a annoying, this is due to the 50Hz low frequency torroid transformer used as it resonates with the 1/2 chopped AC from said device as per Kevin Windrem notes.

As were the other brands use transformerless or High frequency inverters which don't resonate at all.

But the Victrons are a good inverters and reliable with good warranties etc.

Regards

Rob Duthie

NZ

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

John avatar image
John answered ·

Thank you all for responding! That makes a ton of sense and I suspect you're all spot-on. It's definitely worth noting that everything does work, it just sounds unacceptably terrible. I'd love it if there was a component I could add to mitigate this issue, but I imagine if there was an easy fix it would have been mentioned already.

1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

knownot avatar image knownot commented ·
Not an economical option (money or efficiency wise) but I feel an isolation transformer might do it.
0 Likes 0 ·
mauronic avatar image
mauronic answered ·

I found this thread after viewing a van tour with a Brava oven. The owner designed his power system around it. Instead of using a Multiplus, he installed a Cotek inverter.


I want to install an espresso machine and am researching the Brava. I’m curious how annoying the sound would be and if there are “easy fixes” given I already have a MultiPlus installed.

See 20:50

https://youtu.be/BlH6tu87t7Q

1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

novaseant avatar image novaseant commented ·
Did you ever find a solution that would allow you to have a Brava in your van?
0 Likes 0 ·