Tweakers' Asylum

Posted by Tweekeng (A) on February 25, 2014 at 17:25:00

In Reply to: RE: Easy excellent tweak posted by Tweaker456 on February 25, 2014 at 13:42:59

Your life and property are worth more than any tweak.
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Class X is for applications where failure could not lead to electric shock (hot to neutral). Class X1 capacitors are intended to operate safely even in the presence of spikes on the mains supply of up to 4 kV (installation category 3 or overvoltage category 3 according to IEC60664), which are normally industrial supplies, but some standards call up class X1 capacitors if they are connected directly to the mains supply upstream of the equipment fuse, irrespective of the type of mains supply. Class X2 capacitors are intended to operate safely even in the presence of spikes on the mains supply of up to 2.5 kV (installation category 2 or overvoltage category 2 according to IEC60060), which are normally residential, commercial and light industrial supplies. X capacitors can be found from 0.001 uF to at least 10 uF and are only made in film.

Class Y capacitors are for applications where failure could lead to electric shock if the ground connection were lost. This includes hot/neutral to ground, and antenna isolation capacitors. Because Y capacitors shunt current to ground, leakage-current limitations limit their size to a maximum of about 4700 pF in many commercial and industrial applications (but refer to the relevant standard for definite information) and about 470 pF in medical applications.Cappic Larger ones are available however. Y caps are available from 1000 pF to 0.1 uF and are made in both film and ceramic.

• A good read on Line-Filter Capacitors   (Open in New Window)