Hello
I work on UPS and inverter repair daily, most of problems occur with shorted igbt or mosfet
Sometimes I don't find same part number into local market, so I start search for replacement
I can find into voltage and ampere withstand, but how about the switching timing?, how you do with that? " I mean tr, tf, tdon, td off, Qg, Cg, these parameters related to timing
For example, 3kva UPS with blown mosfet number ixfh110n15t2, what the suitable replacement for it?, if find same or higher ampere and voltage, the timing will be different
How can I replace with one and I be sure I'm into safe operating area for mosfet or igbt?
Any ideas?
Attached datasheet

 

Certainly this is a valid question. Any honest manufacturer would provide service information if there was an anticipation that the UPS would ever be repaired.
But my question every time when there is a component failure is "Why did it fail??" For many consumer products the cause of failure is probably insufficient design margins. So for a UPS, where the switching frequency is not so very high, the choice will probably replace both, or all, of the type of power devices with parts rated for the anticipated voltages and currents.

Of course, ALL of the failed UPS devices I have seen were failed because of the batteries having failed.

 

So for a UPS, where the switching frequency is not so very high, the choice will probably replace both, or all, of the type of power devices with parts rated for the anticipated voltages and currents.

How about timing parameters?, you don't take on considerations?

 

If all of the response times are fast enough then it may not matter "how fast enough." And my intention was to suggest replacing the whole set of power devices.

 

If all of the response times are fast enough then it may not matter "how fast enough." And my intention was to suggest replacing the whole set of power devices.

Aha, we replace the broken ones, and it's fine
Some are fast and some are hyper fast, different
What is your point of view for fast?, how I know that no problem happen because wrong timing?

 

"Fast Enough" is when the device delays are an order of magnitude less than the application requirements. "Barely Fast Enough"is when the response time is only a bit less than required. They both work, though.

 

"Fast Enough" is when the device delays are an order of magnitude less than the application requirements. "Barely Fast Enough"is when the response time is only a bit less than required. They both work, though.

Aha, OK, faster not dangerous but slower is
Right?

 

Aha, OK, faster not dangerous but slower is
Right?

RIGHT INDEED!! Faster wins the race, slower loses.