Help identifying an old capacitor

[SirCapsAlot]

Hi,

I need to replace a blown capacitor that's about 25-30 years old and as far as I can tell it's not manufactured anymore so I'm looking for a equivalent replacement.

From my limited understanding of reading capacitor codes I think this is a 2200pF +- 20% 250V-400V ceramic Y1-class capacitor (see attached image). Is that correct?

I assume the 250/400 numbers represent the max voltage according to different certifications?

It's sitting behind a (now destroyed) 12a 250v slow-blow ceramic fuse by the way.

Any help with this would be much appreciated!

[PeteS in CA]

Re: Help identifying an old capacitor

The manufacturer of those parts was Ceramite, a spin-off from Sprague. The series is 30LV. More to the point, Ceramite was bought by Vishay, https://cdn.badcaps-static.com/pdfs/...f797addad4.pdf . They are 2200pF, and any brand's physically compatible Y1-class part could be substituted.

[momaka]

Re: Help identifying an old capacitor

From my limited understanding of reading capacitor codes I think this is a 2200pF +- 20% 250V-400V ceramic Y1-class capacitor (see attached image). Is that correct?

I assume the 250/400 numbers represent the max voltage according to different certifications?

Yes, that's 100% correct.

Seems like your understanding of reading capacitors isn't so limited after all.

Now, is there a reason you are replacing this/these capacitors? Capacitance reading low, perhaps? If not, they should be OK. Sure they are quite old at 25+ years, but ceramics (particularly Y1/Y2 class) don't age that badly. I imagine the black soot on it is the reason why? If so, you can just clean that up with IPA.

Now X1 and X2 class metal film caps are a different story. With age, they can/usually do loose quite a bit of capacitance, especially in noisy environments. Moreover, some of them can fail shorted over time. So X1/X2 caps are more likely to need replacement with advanced age.

[SirCapsAlot]

Re: Help identifying an old capacitor

The manufacturer of those parts was Ceramite, a spin-off from Sprague. The series is 30LV. More to the point, Ceramite was bought by Vishay, https://cdn.badcaps-static.com/pdfs/...f797addad4.pdf . They are 2200pF, and any brand's physically compatible Y1-class part could be substituted.

Yes, that's 100% correct.

Seems like your understanding of reading capacitors isn't so limited after all.

Now, is there a reason you are replacing this/these capacitors? Capacitance reading low, perhaps? If not, they should be OK. Sure they are quite old at 25+ years, but ceramics (particularly Y1/Y2 class) don't age that badly. I imagine the black soot on it is the reason why? If so, you can just clean that up with IPA.

Now X1 and X2 class metal film caps are a different story. With age, they can/usually do loose quite a bit of capacitance, especially in noisy environments. Moreover, some of them can fail shorted over time. So X1/X2 caps are more likely to need replacement with advanced age.

Great, thank you both! I was I bit unsure so it's great to get some confirmation.

Regarding the reason for replacing it. I haven't actually tested the capacitance, I honestly just assumed it was bad when it popped and sprayed soot everywhere haha

[momaka]

Re: Help identifying an old capacitor

No problems!

Well, the question is... did that Y cap really pop and spray soot or is that just residue from the fuse. Clearly if was the cap, then it should be replaced. Otherwise, I'd just clean the soot on it with IPA and not bother with replacing.

[SirCapsAlot]

Re: Help identifying an old capacitor

No problems!

Well, the question is... did that Y cap really pop and spray soot or is that just residue from the fuse. Clearly if was the cap, then it should be replaced. Otherwise, I'd just clean the soot on it with IPA and not bother with replacing.

Yep it was the cap, can't really see it well in the picture but the lower left darker area is actually a hole where the soot sprayed out of.

I replaced it and the fuse yesterday and it worked wonders

[momaka]

Re: Help identifying an old capacitor

Nice! Good to hear you got to the bottom of it.
I'm just surprised to see a Y1-type capacitor fail. Usually those are supposed to be very robust and made for industrial environments. But after 25-30 years, I guess it could have seen some abuse throughout its life.