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    Help identifying an old capacitor

    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!
    Attached Files

    #2
    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.
    PeteS in CA

    Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
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    Comment


      #3
      Re: Help identifying an old capacitor

      Originally posted by SirCapsAlot View Post
      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.

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        #4
        Re: Help identifying an old capacitor

        Originally posted by PeteS in CA View Post
        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.
        Originally posted by momaka View Post
        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

        Comment


          #5
          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.

          Comment


            #6
            Re: Help identifying an old capacitor

            Originally posted by momaka View Post
            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

            Comment


              #7
              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.

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