I'm organizing some capacitors I acquired over the years in my parts bin. There's one large disc capacitor that has me perplexed. It has the markings:

 **ERIE 1000F 10KV 7634**

While it's quite a large capacitor, measuring ~13/16" or 21mm, it's doesn't appear to be large enough to hold 1000F (farads) of capacitance. I tested it with my multimeter and only got 1.260nf which seems more likely. The 10KV (kilovolts) also appears to be very high but seems probable given its size. I searched for it using the numbers on the marking but it yielded no pertinent information.

Am I mistaking this for a capacitor when it is actually another similar looking component, such as an MOV or voltage suppressor? If so, what does the 1000F and 10KV mean?



1 Answer 1


It’s a 1nF (1000pF) high voltage (10kV) ceramic capacitor. The F is the tolerance (+/-7.5%). If you connect about a billion of them in parallel you will have a 1F 10kV capacitor.

You’d have to check the datasheet to see at what voltage the capacitance is specified.

Because of the high voltage rating the leads are not brought out beside each other, as would be usual.

  • \$\begingroup\$ Tolerance code F is ±1%. \$\endgroup\$ Sep 13, 2020 at 15:49
  • \$\begingroup\$ @RohatKılıç EIA code is +/-7.5% That is not a 1% capacitor. \$\endgroup\$ Sep 13, 2020 at 15:53
  • \$\begingroup\$ If I know correctly, EIA code F indicates the maximum capacitance change (±7.5%) over the rated temperature range. And the coding convention is different (e.g. X7F indicates a ±7.5% capacitance change over -55..+125°C range). Please correct me if I'm wrong. \$\endgroup\$ Sep 13, 2020 at 16:00
  • \$\begingroup\$ Thanks. So the EIA (or whatever responsible body) failed to do its job of creating a consistent and unambiguous standard. Why pick the letter F which is also the symbol for Farads? If I was an absolute ruler, I would hold them liable for every engineering error resulting from a misinterpretation. \$\endgroup\$
    – user148298
    Sep 13, 2020 at 16:22
  • \$\begingroup\$ @user148298 Capacitor markings are particularly poorly standardized, as evidenced by the number of questions here regarding capacitors. How is a standards body in Germany or whatever going to tell an American or Chinese manufacturer what to do. \$\endgroup\$ Sep 13, 2020 at 16:27

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