UPS

Get a job at UPS

"how to avoid this kind of situation"

1. Unplug the device.

2. Consult the owner's manual.

3. Call the manufacturer's tech service.

4. Ask a competent electrician to trouble shoot it.

5. Simply replace it.

GA. Nothing to add.

Since you could not contact the fabricator of this UPS, stop buying from low bidders with questionable product.

https://www.fujielectric.com/products/semiconductor/model/igbt/application/box/doc/pdf/RH984b/REH984b_04a.pdf

As good a guess as any on the actual manufacturer. Saturation Trip sounds like an external overload of some sort, but without more detail, at least Manufacturer and Model and Age, type of load, difficult to help & guide...

it's its

For what it's worth, the poster's command of the English language is much better than my command of Hindi or any other language outside of my mother tongue.

This AP spent his, and our, time to pick this nit?

How come AP's are allowed to post anyway? ^{(Don't answer that. I heard all the lame excuses already)}

A "saturation fault" in an IGBT based device, like a UPS, is generally indicative of a problem with the voltage between the collector and emitter of an IGBT transistor. In modern devices this is now usually TTL level signals, so +5VDC with a "trip" threshold of around +7VDC. That means one of several possibilities:

1. You have a serious defect in your firing board, in which case the problem will repeat itself with an new IGBT module and cost you more money in fuses and IGBTs.
2. Bad grounding resulting in excessive noise in the system that ends up 'fooling" the sensing elements into thinking the IGBT collector/emitter voltage is too high. This too will repeat itself.
3. A short circuit on the output side, which makes the IGBT the highest impedance device in the circuit for that brief moment until the fuses clear. This will not only repeat itself but likely start cascading and taking out more and more parts of the system.

Give that the fuses cleared, I would take a wild guess at #3...