Can any one tell me what I would need to replace this yellow disc. I have another board that this part has burned up, and I need to find a replacement. The manufacturer is Buss, however I cannot find any information with the numbers printed on it. The following is printed on the side: Buss M131 EL

I have also included a picture Thanks in advance for your help enter image description here

  • 2
    \$\begingroup\$ That looks like a varistor, not a capacitor. Why does it need replacement? \$\endgroup\$
    – Justme
    Dec 19, 2019 at 5:52
  • \$\begingroup\$ This is not the board that needs it, the one that needs it's burnt off the board, black and unreadable \$\endgroup\$ Dec 19, 2019 at 6:10
  • 1
    \$\begingroup\$ Based on the number 130, it could be a varistor meant to tolerate 130 Vac for protecting 120 Vac mains voltage. But exact parameters are not known how much energy this can handle, as I could not find the datasheet easily. \$\endgroup\$
    – Justme
    Dec 19, 2019 at 6:35
  • \$\begingroup\$ Ok. Well now I know a little more about it. Thank you for your help \$\endgroup\$ Dec 19, 2019 at 6:40
  • \$\begingroup\$ Buss stands for BUSSMANN. Bussmann and Cooper. It could be a MOV14131 where 14 stands for the disc diameter. I can find pictures, but no datasheet for those series. You need to find a datasheet to correctly determine what device you have. \$\endgroup\$
    – Huisman
    Dec 19, 2019 at 15:29

1 Answer 1


The correct size and speed of fuse must be used.


simulate this circuit – Schematic created using CircuitLab

The withholding rating must be about 10% above max range voltage.

here is a list of 14mm disks

  • \$\begingroup\$ What's the connection of your answer with the question? + The schematic doesn't make any sens. The symbol for the varistor is wrong. \$\endgroup\$
    – Fredled
    Oct 21, 2020 at 23:32
  • \$\begingroup\$ @Fredled the choice of MOV/varistors was given. The symbol for varistors was not found. Capiche? The advice for fusing is essential for protection from MOV damage \$\endgroup\$ Oct 22, 2020 at 8:35
  • \$\begingroup\$ -1 to Fred’s misunderstand \$\endgroup\$ Oct 22, 2020 at 17:40
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    \$\begingroup\$ I agree about the fuse part but it's not answering the question and irrelevant because the OP is just replacing one part in an existing circuit.. You can edit a customized box when you don't find the symbol rather than using a misleading one. And what is a bidirectional TVS diode - also with a wrong symbol - doing there? \$\endgroup\$
    – Fredled
    Oct 22, 2020 at 22:18
  • \$\begingroup\$ Fred you miss a major point , not asked. how do you prevent the MOv from burning up in future. I think outside the box, you? \$\endgroup\$ Oct 22, 2020 at 23:21

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