Micromaster 440 burned

[chuzkin]

Dear friends.

Today I made a terrible mistake. I connected a SIEMENS MICROMASTER 440 220VAC input to 440VAC. After some seconds, smoke appears and I cut the circuit braker. Then, I change power supply to 220VAC (correct) and when turn on the braker, something blew up inside the VFD.
I checked inside and it seems it was just 1 of the 3 input (line) varistor S20 K275. All the other boards look fine. I will change varistor. Capacitors look fine (how can I test them?), and rectifier diodes are ok.


Do you think varistor can be the only damaged component?
What else should I check, and how to test?

Thanks a lot.

Best regards.

 

[pradeep.g.belchada]

check the igbt it may be short

- - - Updated - - -

check smps & post clear images

 

[chuzkin]

check the igbt it may be short

- - - Updated - - -

check smps & post clear images

Thanks a lot friends.

I finally solved. It was just one of the 3 varistors.