12-31-2013, 08:14 PM
Well, I guess maybe in some cases it helps and in some it does not. Also since it goes only to one prong the plug may need to be rotated when plugged to find in what position the noise is minimal.
In any case, Y and X are ratings for line filter caps and in particular Y guarantees that the cap does not fail in shorted mode, thus guaranteeing you are not going to be electrocuted if it fails. Which is not to say that you might not receive a minor shock if you decided to touch the chassis and the Earth at the same time, as 10nF is in excess of today's recommended value for 'touch current' (that is 10nF will allow more current that the specs dictate). Still, this is far from the electrocuting value.
In any case, Y and X are ratings for line filter caps and in particular Y guarantees that the cap does not fail in shorted mode, thus guaranteeing you are not going to be electrocuted if it fails. Which is not to say that you might not receive a minor shock if you decided to touch the chassis and the Earth at the same time, as 10nF is in excess of today's recommended value for 'touch current' (that is 10nF will allow more current that the specs dictate). Still, this is far from the electrocuting value.