Good Source for Parts?

RS Components (usual disclaimer).

Mouser, Allied, Jameco, Digikey

...maybe Alltronics

I really like MCM

thanks, I know and use most of them, but none carry the power electronics components I need..

any other please?

Please state the part numbers of the equipment required.

right now I need SKiiP32NAB12T1 by Semicron, I know there is 13000 hits for it, but I need to hear about personal positive experience

So far I got a couple from the US that blew in short order (the original one is working fine in a drive I'm working on) same thing in with one fro Malaysia, the next two I got from Shanghai are fakes that don't show any semiconductor junctions inside!, empty box..

Maybe one of these?

http://www.datasheets360.com/search/results?query=SKiiP32NAB12T1

I use a lot of semikron components and buy them @ SEMIKRON. they give also a good service and will tell you where to buy reliably.

They even send samples.

SEMIKRON Germany -

I think it's the soundest advise here, don't want to risk any more surprises..

I'm sorry to hear about your bad parts, but I'd like to make one comment about IGBTs. It's been my experience that these guys are VERY rugged and with a proper drive circuit they rarely fail. For example most can drive a full short (meaning they're running at their high intrinsic "current limit") for 5 to 10us, so that a desaturation-detection feature on the driver will protect them from even that kind of catastrophic mistreatment.

However they have trouble with excess gate voltages, even for a short instant. Properly designed circuits won't create such voltages, under any circumstance. So I wonder if your circuit has some design problems, maybe is missing a proper snubber, etc. Switched IGBTs can create very high dI/dt, causing high V = L dI/dt voltages to appear across wiring inductance, etc. If your circuit works at low load but fails at higher load (where higher I implies higher dI/dt), you may have such a problem.

thanks for chipping in, but it's a industry-used drive (VACON CXS4 series) performing flawlessly most of the time.

I'm dealing with a defective drive (not defective design), your suggestion is well placed though, the next attempt when I get the new chips (or even before) will be to compare the driving stages of a bad one with working one, I don't have to mention that I don't have any schematics.

It looks like I'll have a chance to put my hands on one an put my trusted HuntronTracker signature analyzer to work.

It would be a good idea to determine the nature of the failure. For example, defective gate-drain for the input MOSFET (a common failure from excess gate voltage) will mean the device turns on if the C voltage is taken more than 4 to 8V above the E voltage, with a say 1k from G to E (a simple test with a bench power supply).

Second, it'd be useful to know which device was failing. Is it always the same one? Maybe there's a defective part in the circuitry surrounding the IGBT, e.g. that device's snubber.

BTW, the scene you're experiencing is why I don't favor designing with extensive specialized modules, like bridges with six IGBTs in one module. Not only does the specialized part drive costs up during manufacturing, but it makes repair painful and difficult, getting your hands on the exact replacement part.

thanks for elaborating further, one IGBT has a shorts between three junctions, I'll check the driver circuitry when I have a working drive to compare and get back to you with my findings.

Kaztronics-

If you are having so many failures of imported and domestic supplied ones, are you sure that these units are the best ones for the circuit that you are working with? Should the circuit design be changed? Should a component with a higher power capability rating be used?

Some times it is the wrong application and not bad components.

Good Luck, Old Salt

this is for a VACON HF drives, there are about 20 used in my client's machines, they rarely fail, but when they fail that's the part to use. I won't be correcting VACON's design for sure..

Me zendt a perzonaal messaaga toyo. Prosit

If some of the vendors already listed don't carry the part you need then you may need to check the web site for the part and only deal with their listed distributors.

Other web sites:
http://www.em.avnet.com/en-us/design/linecard/Pages/default.aspx?Filter=AllMan Avnet line card
http://www.arrow.com Arrow Electronics
http://avnetexpress.avnet.com more or less the old "Hamilton Avnet"

I have found Newark, Allied and Mouser to be reliable.

yes, they are, but don't have what I need..

Try the drive manufacture. Surely they will sell repair parts!

nope, they will sell me a new drive..