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avocet-wave asked

(Slightly) bulging capacitors on Victron Energy Quattro 24V 5000VA (Model QUA245020000)

Hi there

I have a 10 year Victron Energy Quattro 24V 5000VA (Model QUA245020000) that I am attempting to repair. It recently blew a MOSFET and in stripping it back to swap out the blown transistor I noticed that the capacitors were beginning to bulge. I have a couple of quick questions:

1/ In a unit 10 years old which has had non continuous use with significant periods of time idle is it normal to see some swelling of the capacitors and is this a sign that they should be replaced?

2/ Is it likely / possible that the capacitors caused the MOSFET to fail?

If anyone has some experience of this situation and could offer some advice that would be very much appreciated. While I have the unit stripped back I don't want to miss the opportunity to get in front of a future potential problem.

Many thanks, alex

MultiPlus Quattro Inverter Charger
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2 Answers
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wkirby answered ·

I have a 15+ year old unit which is still in perfect condition. It was in an ambulance for most of that time.
One of the main factors that could affect the input capacitors is DC ripple. The higher the ripple current over the capacitors, the shorter life they'll enjoy. DC ripple is always there, it is the job of those capacitors to reduce it, but excessive DC ripple will give those capacitors more of a workout.
Keep DC ripple low by maintaining good connections, using properly sized wiring and a healthy battery bank.

If the capacitors are showing signs of age or degradation, then you should replace them all, no harm can come of that.
When you replace the MOSFET, check all of the other ones too. Also be sure to check the MOSFET drivers too. A shorted MOSFET can damage the driver stages also.

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Silvio Franceschini avatar image
Silvio Franceschini answered ·

Can 230V output capacitors cause overload and shutdown with crackle noises?


My older MP 24/5000 had now twice Overload Shutdowns without any load on the output. First one over one month ago. That time I switched the unit off and waited one night. reconfigure just in case and had no issues for more than a month.

Now the error is back. From the crackling noice I guess on breakthroug capacitor, which cause a short cut over phase and neurtal. No Error LED’s, just overload when the cracke starts and unit shut down.


I’m not sure if its also temperature related, unit is at around 5-7 degrees and issue don’t show up strait away after switch ON, it vary around 1min after start up.


As you guys seams to know the units and its cirquit boards, you may have an idea where to search. Any help is very appreciated


Cheers Freens


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