Help needed with repair of an Enecsys SMI480-60 Solar inverter

Thread Starter

Nicootje

Joined Apr 10, 2021
1
Hello,

i am trying to repair an Enecsys SMI 480-60 Solar inverter.

I was looking for a schematic on the internet for quit a long time and finally found a schematic on this forum wich is very great.
This thread: https://forum.allaboutcircuits.com/threads/solar-micro-inverter-power-management.134979/

I inspected the unit en found no burned components, the fuse is ok and there are no short-circuited power mosfets.

This inverter behaves as follows when it is connected to the 220 volts and the solar panels are connected:
- on a properly functioning inverter, the yield of these panels is approximately 31 watts just before conversion;
- on the enecsys inverter everything stays at 0 for about 2 minutes;
- after about 2 minutes, my power meter indicates 2 watts as yield (or decrease) and about 41 VA (apparent power);
- shortly afterwards everything goes back to 0 and it stays that way.

It looks like the DC circuit is okay and there is an error somewhere that shuts things down.

I hope someone can point me in a direction to track down and fix this error?
 

CD4046

Joined Sep 13, 2021
1
Hello!

I may have a solution to your problem.

There are a few op-amps on the board.
Check them for extensive heat buildup - this should not happen.
I would recommend using a thermal camera as it measures without electrical conductivity.
If one of them gets warm, change it and try again.

Could you provide your schematic to us? The link is not helpful at all as there is no such file.

Good luck with your inverter! :)
 

Irving

Joined Jan 30, 2016
2,105
Hello!

I may have a solution to your problem.

There are a few op-amps on the board.
Check them for extensive heat buildup - this should not happen.
I would recommend using a thermal camera as it measures without electrical conductivity.
If one of them gets warm, change it and try again.

Could you provide your schematic to us? The link is not helpful at all as there is no such file.

Good luck with your inverter! :)
With respect that's not a solution, just very general guidance, and a thermal camera is a nice to have; most people won't have access to one.

The schematic is an attachment to the first post in the link above, so the link is very helpful.

@Nicootje - MPPT inverters are tricky beasts - to best advise you, we need to know first what is your level of experience/expertise with this sort of repair and on high-voltage equipment? What test equipment do you have available?
 
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