I agree with Dave.
And as for a comment about reliability of Y type capacitors. They're no more reliable, it's just that they are far less likely to fail short circuit.
Anyone want to see an X rated cap that's failed short circuit (like they're NOT supposed to do either)?
Steve maybe you could have proposed a better wording for my comment instead of the comment you posted.
I also found some information about X and Y capacitors. Maybe robustness is a better word but they do seem to be tested to enhanced reliability standards.
Extract :http://powerblog.vicorpower.com/2013/06/what-are-y-capacitors/
When does capacitor reliability become critical to safety?
Line filter capacitors are classified either as X-capacitors or Y-capacitors. X-capacitors are connected between line and neutral, to protect against differential mode interference. Their failure does not create conditions for dangerous electric shock, although it can create a fire risk. However Y-capacitors are designed to filter out common-mode noise, and are connected between line and chassis; if they short-circuit, they create a risk of shock to the user.
How are Y-Capacitors designed and deployed to ensure safety?
Y-capacitors are designed to enhanced
electrical and mechanical reliability standards. Capacitance values are also limited to reduce the current passing through the capacitor when AC voltage is applied, and reduce the energy stored to a safe limit when DC voltage is applied. Capacitors must be tested to applicable standards to qualify them for use as Y-capacitors.
Extract : http://www.vishay.com/docs/26033/gentechinfofilm.pdf
Y-Capacitors
Capacitors for suppression of asymmetrical interference voltage, and are located between a live wire and a metal case which may be touched. High electrical and mechanical reliability to prevent short-circuits in the capacitors. The capacitance value is limited, in order to reduce the AC current flowing through the capacitor. By following these technical requirements, it is intended that its failure will not lead to the risk of electrical shock, making the device with Y capacitor (in conjunction with other protective measures) safe to human beings and animals.
Extract : http://www.tecategroup.com/capacitors/applications/ac-safety-capacitors.php
T1= 10 µsecond, T2=700 µsecond in Telecom applications (IEC 60950)
T1= 1.2 µsecond, T2=500 µsecond in Mains power applications (IEC 60384-14)
Both X and Y capacitors have the same potential for failure short circuit but Y capacitors are subjected to higher surge voltages during approvals. So I suppose if they were used in place of X types then they would indicate a possible increase in reliability.
Adam