The standard which applies is IEC 60384-14 Fixed capacitors for use in electronic equipment-Part 14, Sectional Specification; Fixed capacitors for electromagnetic interference suppression and connection to the supply mains.
I only have a draft in my possession. It states "Capacitor of Class X, a capacitor of a type suitable for use in situations where failure of the capacitor would not lead to danger of electric shock...divided into 3 sub-classes according to the peak voltage of the impulses superimposed on the mains voltage to which they may be subjected in service." "Capacitor of Class Y, a capacitor suitable for use in situations where failure of the capacitor could lead to danger of electric shock... divided into 4 sub-classes Y1, Y2, Y3, and Y4." I'm sure you could get lots of information from any filter manufacturer, especially Schaffner, or from a capacitor manufacturere such as EVOX/RIFA. I can tell you now that it is a complicated subject that I am not expert on, but I have a file of magazine articles, etc. You only have to look at clause 1.5.6 Mains Capacitors of IEC 60950 to see how complicated it is. Nick - if you want me to send you copies of anything I have on the subject, let me know your address, but anything I have goes back to around 1992, and the draft IEC 384-14 which became IEC 384-14: 1993. Regards. John Crabb, Development Excellence (Product Safety) , NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2 3XX E-Mail :[email protected] Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus 6-341-2289. > -----Original Message----- > From: Nick Williams [SMTP:[email protected]] > Sent: 08 September 1999 10:12 > To: [email protected] > Subject: Suppression capacitors > > > I'd appreciate it if someone could confirm (and/or add to) the following, > which is my understanding of the application of the various classes of > supression capacitor: > > X2 - suitable for applications where the supply is connected directly > across the capacitor but the appliance is not permanently connected; > > X1 - Suitable for applications where the supply is connected directly > across the capacitor and the appliance is permanently connected; > > Y - Suitable for applications where the capacitor is connected > directly between the supply and accessible conductive parts. > These definitions are based on Clause 14.2 of EN60065 but any references > to > other standards which apply would also be useful. > > Thanks > > Nick. > --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
