Snap-in Electrolytic capacitor gets hollow and puffy over a

I have an 'extended life' i.e. 7000 working hours 250V 330uF
electrolytic snap-in capacitor.

It is used in a simple circuit to provide to provide a DC voltage from
an input voltage of 100VAC to power 90VDC motors.

Why would the top of the capacitor start getting puffy and hollow,
comparable to the touch of a membrane switch, after only 2 years of
operation? I'm suspecting that occasional regenerative voltages may be
causing the voltage to exceed the cap's paramters.

Mike

 

[Leon Heller]

<valemike@yahoo.com> wrote in message
news:1103904820.265100.241100@c13g2000cwb.googlegroups.com...

I have an 'extended life' i.e. 7000 working hours 250V 330uF
electrolytic snap-in capacitor.

It is used in a simple circuit to provide to provide a DC voltage from
an input voltage of 100VAC to power 90VDC motors.

Why would the top of the capacitor start getting puffy and hollow,
comparable to the touch of a membrane switch, after only 2 years of
operation? I'm suspecting that occasional regenerative voltages may be
causing the voltage to exceed the cap's paramters.

I make 2 years = 17,520 hours, so it should have died a long time ago, even
at 90V.

I'd replace it before it starts leaking or explodes. Temperature can also
affect life, BTW.

Leon