Flyback transformer insulation testing?

[Flyback]

Hi,
We have a offline flyback transformer which is rated to 4kv/3mA/2seconds.
It we continuously apply 4kv rms (50Hz) to it, (ie for way longer than 2 seconds) then after how long will it eventually fail the insulation test?

 

[ZipZapOuch]

Hi,
We have a offline flyback transformer which is rated to 4kv/3mA/2seconds.
It we continuously apply 4kv rms (50Hz) to it, (ie for way longer than 2 seconds) then after how long will it eventually fail the insulation test?

It depends on the safety factor used to design the transformer and the safety factor in the temperature specification and dielectric breakdown voltage of the insulation used for the wire. So, without more information I would estimate sometime between 2-seconds and forever.