Polarized electrolytic in AC (start cap motor) ..#2

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Joined Feb 25, 2018
So - resurrecting (and slightly re-vectoring) this thread: When my garage opener "start" cap of ~55uF died, I had only electronics-style high-voltage axial caps available as emergency spares... A pair of polarized nominal 100uF/400v in series neg-neg yielded a 53uF <measured> non-polarized 'lytic.

Now for the question: At a fraction of the size of its predecessor (less foil, electrolyte-paste, etc), but arguably better voltage and ESR <1.2 ohm measured on bridge> specifications - do we anticipate that this pair will somehow have shortened life? I'd like to think that these good Sprague's would outlast the opener's factory cap - but are there heating/power-dissipation considerations? Ostensibly, not being a "run" cap, a "start" cap is in circuit only momentarily. ...'Thoughts?...

Mod: link to old thread.