Hello everyone!

I have a hybrid MPPT solar inverter (5KVA) with an incoming grid of 220V.

I fixed an issue with the inverter not turning on. However, after doing this, as soon as I connect the AC-IN wiring when trying to re-install, the inverter will reboot itself repeatedly, never turning on completely. (I apologize for not having taken a video, I was so frustrated!).

The fans will seem to start, but then turn off, and then again begin the process this way. The display shows the batteries statuses (almost full) and the AC IN voltage at 232V. That is, for a less than a second, the inverter will show its whole screen as if everything was in working condition, even attempting to turn on the fans, but it will never come up properly.

The LED lights show green-green-red, meaning that batteries and the AC are ok, but the inverter is faulty. These lights are not blinking, but stable.

So far, changed several of the components near the MOSFETS, including two safety capacitors and the smallish electrolytic ones, as well, but nothing has solved the issue. I also changed all of the PNP A1020 transistors

Does anyone have any ideas about where to look? Could it be one the huge capacitors? They appear to be working when tested with the multimeter and they don't seem visually damaged.

Thank you greatly!

 

Could it be one the huge capacitors? They appear to be working when tested with the multimeter and they don't seem visually damaged.

Yes. Capacitors can fail on ESR (increasing series resistance) before they show a loss of capacitance or visual signs.

Folks here will need a lot more info to help you further: Good clean photos, ideally a schematic, a brand and model number. New members may be restricted on what they can post. If you have something but can't include it, maybe there's a fix.

 

I fixed an issue with the inverter not turning on.

How did you fix that?

 

How did you fix that?

Hi crutschow,
I changed the capacitors near the switch, there were a couple of them that seemed to have a bump on top.

 

Yes. Capacitors can fail on ESR (increasing series resistance) before they show a loss of capacitance or visual signs.

Folks here will need a lot more info to help you further: Good clean photos, ideally a schematic, a brand and model number. New members may be restricted on what they can post. If you have something but can't include it, maybe there's a fix.

Hi wayneh,
I'm not sure that photos would help, since there are no visible signs of any deffects. However, I found the service manual online, which is on this link:
https://www.scribd.com/document/754791163/Guide-depannage-Axpert-VM2-5KVA-idem-SuperWatt
I am planning on checking again the SPS. Since the problem begins after having connected the AC IN, perhaps there is some component that is not all the way failing, but worn enough to cause a drop in efficiency.
Thank you.