Saftety Capacitor K rating clarification

[radlebb]

Hi,

I'm a bit confused by the use of K as a capacitance rating on Safety Capacitors. I see lots of people saying that K = uF, though I see other sites saying K is the tolerance, i.e. +/-10%

The yellow Dain cap is rated at 0.82K, which would might be 0.82uF with +/-10%. Or does it mean 0.82 x 1000pF, i.e. 820pF or 0.00082uF?

I was looking for a replacement so I went with 0.82uF and ordered https://www.we-online.com/components/products/datasheet/890324025047CS.pdf

This Wurth cap says it's 824K, which looking at the sheet seems to mean 824,000pF (and in this case the K might not relate to tolerance but means x 1000pF... though it does still say +/-10%)? So that would be 820nF and 0.82uF.

So, have I got the right spec replacement here? Or should I have gotten an 820pF?

Thanks

[Kleinstein]

The K is to signal the tolerance and not the capacitance.

The numbers are usually either µF, pF or a 3 digit code like 123 for  12*10^3 pF
So the 0,82K would be either 0,82 µF or 0,82 pF and  0,82 pF would be way to small to make sense.

If in doubt the datasheet will tell - very few series have such a large range that there is any doubt between µF or pF.

[wasedadoc]

Those are both 820nF.

The yellow one is marked as 0.82 (uF).  The red one is 82 x 10^4 (pF).

[TimFox]

Popular tolerance codes for component values:
K = 10%
J = 5%
F = 1%

[radlebb]

Thanks all. So in this case since the yellow one is decimal it's likely to be uF and the red one is using the 3 digit convention in pF. Briliant!