Capacitior Issues

When I read what you wrote about using different brands and having the same problem, the first question I asked was, "What is the common thread?"

I'd venture a guess the problem doesn't have to do with a deteriorating quality of electronic parts from all manufacturers, but something more simple. If you put various brands of light bulbs in a socket and they all blow continually, do you suspect a problem with all light bulbs or the socket (or the power supply, etc)?

Based on the fact you've used different brands, the blown cap seems like a symptom of another problem to me.

Well, the schematic is fairly simple and we have been doing this for 30 years. The capacitance and vac is set by the compressor manufacturer, Copeland, and we have asked for and received verification of their specifications, so we're certain that the application is correct.

This is a good forum for electronic problems, especially capacitors.