openinverter forum

Is there a simple or recommended test I can perform on a Tesla SDU inverter before installing an OpenInverter logic board to ensure that the power electronics, etc are actually good? How can I ensure the inverter is actually good before swapping the logic boards? Thanks!!

You can check whether an IGBT failed closed by connecting a current limited power supply (=any supply with series light bulb) :
1. positive to DC+, negative to one phase after another
2. negative to DC-, positive to one phase after another

There must never be any current flow. Still an IGBT could now be failed open but that is an unusual failure mode. Test voltage 12V should be sufficient.

Perfect, thank you!

Is there any way to check if an SDU inverter is good without breaking the 3-phase wire VOID seal? Is there some way to check it via the logic board connector only?

I'd like to be able to test a drive unit at the wrecking yard before taking possession of it, if possible.

nubster wrote: ↑Thu Sep 07, 2023 8:01 pm Is there any way to check if an SDU inverter is good without breaking the 3-phase wire VOID seal? Is there some way to check it via the logic board connector only?

Unfortunately not. As far as I know, the only way to test is at the 3-phase void seal. Worse still, in my experience, many bad units don't appear to be failed, and even work at low voltage, but fail as soon as HV is applied again.

You get a rough check with diode mode and connecting the multimeter in reverse to DC+ and -
If flow voltage is 0.3V one IGBT is failed shoirted, if flow voltage is 0.6V then it may be ok or one of the harder to find failures

[media] [/media]

This is how I did it. Will link it in the wiki .

Excellent, thanks again!