I would like to know if I can replace a safety Y2 capacitor (222m 300V - which is a 2.2nf-)with a safety X2 capacitor temporarily. I'm in a hurry and I already ordered the replacement part but while I'm waiting I would like to know what do I have in my hands to keep the device working. My device has 220V input and 12V5A output.

I read here that :

A Y2 capacitor can safely be used in place of an X2 capacitor, but an X2 capacitor should not be used in place of a Y2 capacitor. This is because, although an X2-type capacitor would work and filter noise sufficiently, it would not meet the line-to-ground safety standards. Y2 safety capacitors are more robust, are able to withstand higher peak impulse voltages, and are designed to fail open as opposed to failing short

But as I said it's for a very short period of time (like a 3 weeks or so)

Or maybe another idea ? Classic 1KV ceramic capacitor maybe can do the work ? Thanks


The problem seems to be somwhere else I will open a new topic. Thanks !

  • \$\begingroup\$ fail open is different to fail short. How about just leave it absent for 3 weeks? If you put it in, do you feel lucky, punk? \$\endgroup\$ – Neil_UK Jul 8 '20 at 12:45
  • \$\begingroup\$ Do you know why the Y2 capacitor failed in the first place? These parts are generally extremely robust. \$\endgroup\$ – Adam Lawrence Jul 8 '20 at 12:54
  • \$\begingroup\$ Not at all, but I just realised that I have 2nf in capacitor mode and an O.L in resitance mode between it's pins. So maybe my conclusion isn't correct at all. \$\endgroup\$ – Martin Jul 8 '20 at 13:00

The fact that you are having to replace a Y class capacitor means that it failed in a benign manner without catching fire or smoke. You can't say the same for X class capacitors because these can fail short circuit.

In addition, you can use a Y class capacitor in front of a fuse but you can't with an X class capacitor hence, what you propose could be very risky. Y class capacitors are designed to fail open-circuit.

A Y2 capacitor is rated to withstand a peak impulse of 5 kV. An X2 capacitor is only rated for 2.5 kV peak impulse.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.