Good day, thank you for your kind response
@coulomb
It's not clear whether you replaced all the MOVs. It would seem a good idea to replace all MOVs after a lightning event.
I didn't
, I just replace the blowed one, because I couldn't find a good MOV like the original here in Argentina neither in Brasil, so I replace it with a cheaper one. I have readed your post about what happen with MOVs after lightning events, so in the first place I though that some of the output MOVs were damaged and acting as a load when more than 220V is apllied on them.
To disregard, I cut all the MOVs out of the board
Nothing changes, the display shows the same gost load (~400 VA pure reactive).
I put them in again.
If the current transformer is blown, then I don't see how you could obtain a replacement. But it may be the burden resistor (a low valued resistor on the output of the current transformer), or the op-amp that it connects to, or associated parts. That op-amp may be on the control board (the daughter board with the processor on it), at the bottom of the photo). I'm not ware of any schematics or even partial schematic traces for that part of the circuit. The op-amps seem to be 8-pin SOIC types.
You were completely right
. That transformer is labeled "CT1", I didn't know about it.
[ Edit Coulomb: Google user content for two images expired. I've added two of my own, that I hope serve a similar purpose. ]
- CT1 location.jpg (118.96 KiB) Viewed 3211 times
Found that burden resistor on the output of the current transformer.
- CT1 under board labelled.jpg (348.17 KiB) Viewed 3211 times
The resistor was completely open. [ Edit: the above is for a 5 kVA model, with two burden resistors populated. Some smaller models seem to use only one burden resistor. ] After replaced it with a new one, the inverter is working without errors. Now I just need to connect it to the solar panels to be sure it will work with them.
There are those op-amps you mentioned. Connected to the pin 4 of the control board, there is a TL074I associated to the current transformer.
So far, I'm very grateful for your help, thank you very much!