Anyone knows these parts S20ZND06 and SC8K250ZD?

[max.wwwang]

I got this at recycle centre. It appears to be a 3-phase rectifier bridge. But strange enough I could not find the datasheets for the two parts S20ZND06 and SC8K250ZD. Both have 3 poles each, +/~/- for S20ZND06, and K/C/A for SC8K250ZD. I believe S20ZND06 is a dual diode module. No idea what K/C/A are, though K or C probably Cathode and A Anode.

Also intriguing is that each pair of S20ZND06 and SC8K250ZD are connected in parallel +/K, ~/C, and -/C, which makes me think C probably stands for "Common". Easy to understand identical parts in parallel to have higher capacity or rating (though sometimes not that simple) but here two parts are not the same.

All the five terminals of the module behave the way as a 3-phase rectifier bridge does when testing with a multi meter.

Other than info about these two components, does anyone know the reason for such topology?

[fzabkar]

S20ZND06 is a Shindengen part, as far as I can tell. The following datasheet is for a different part (a 3-Phase Bridge Diode, S20VT60), but I believe you are correct about S20ZND06 being a dual diode. The rating would be 20A, 600V (or 60V?), if the other datasheet is any guide.

https://au.mouser.com/datasheet/2/366/shins03085_1-2282253.pdf

In fact, I'm wondering whether the S20VT60 performs essentially the same function as 3 x S20ZND06.

[max.wwwang]

S20ZND06 is a Shindengen part, as far as I can tell. The following datasheet is for a different part (a 3-Phase Bridge Diode, S20VT60), but I believe you are correct about S20ZND06 being a dual diode. The rating would be 20A, 600V (or 60V?), if the other datasheet is any guide.

https://au.mouser.com/datasheet/2/366/shins03085_1-2282253.pdf

In fact, I'm wondering whether the S20VT60 performs essentially the same function as 3 x S20ZND06.

Thank you. That’s helpful. Yes the part you mentioned indeed looks like three dual diodes, which is a three phase rectifier in a single chip.

I also believed it should be ok with 240/380v (not unreasonable to be rated as 600V given the peak voltage of AC, and given it obviously accepts three phase AC input). When there was no information whatsoever, I connected it to single phase mains, to two of the three input terminals. Unfortunately the house power tripped in a second. One chip (rather half) with the K/C/A terminals was blown ( becoming short both ways).

From the datasheet of S20VT60, the current rating of S20ZND06 is probably 20A. But the gauge of the wires for DC output seems much heavier than that.

(Meant to have two more photos but they didn’t show up. Will do later.)

[max.wwwang]

more photos

[amyk]

I also believed it should be ok with 240/380v (not unreasonable to be rated as 600V given the peak voltage of AC, and given it obviously accepts three phase AC input). When there was no information whatsoever, I connected it to single phase mains, to two of the three input terminals. Unfortunately the house power tripped in a second. One chip (rather half) with the K/C/A terminals was blown ( becoming short both ways).

Did you check with a multimeter first? There was probably a reason it was scrapped, after all...

[max.wwwang]

Did you check with a multimeter first? There was probably a reason it was scrapped, after all...

Of course I did. It all measured like a working three phase rectifier bridge. But I don’t think I can measure its rating with a multimeter.

Your point of why it got scrapped understood. But very often scrapped units have perfectly working parts or assemblies inside. Very likely this is one of these.

Put rating aside, I’m most interested in the way three pairs of different parts are connected in parallel. By the way, I got another one after blowing the first one, which I’ve taken off the mysterious parts leaving only a straightforward bridge, So I now still have a probably working one to further test/play with. Obviously I will not test it with house mains directly without a good reason.