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Rifa capacitors again
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TimFox:
There have been many posts here about Rifa safety capacitors (usually class X, I believe) that have failed in commercial equipment, either discrete components or included in mains-input line filter modules.
I own some test equipment from the era in question (such as -hp-), but have yet to suffer this problem (knock on wood).
In the US, of course, my capacitors have been exposed to only 120 V, but the equipment is designed to apply either 120 or 240 V to the components in question, depending on country.
Obviously, the stress on an individual capacitor is worse at 240 V than at 120 V.
In the actual experience of the members here, is this problem much more prevalent in 240 V countries?
mawyatt:
For US use (120VAC), had one explode in a 2400 series Tek scope. Also noted the other Rifa caps in old HP and Tek equipment are cracked, mostly the larger values.

Best
andy2000:
I've had two go off on me, just after powering on a long disused piece of equipment. 

I always replace them when I see them, but I have a lot of equipment that probably still has them since I haven't checked everything I own.  I've never had one fail in something that's used regularly.  It's possible that frequent use helps prevent them from absorbing moisture. 
m k:
Don't know about Rifa or Class-X but impression of Class-Y was that they are leaking.
(from 240V and 90's computer stuff)
Maybe Class-X stuff were better or local approval was tighter.
jonpaul:
Class Y are designed for CM noisette surpression,  a maximum leaking current within safety limit at 240V usually 2200 or 4700 pF. Never seen one fail, low stress.

The X caps are 470 nf, line to line have a continous AC current. They are the failure prone

Many other 1970s stacked or wrapped foil caps have such issues.

The Schaeffer EMI line filters and filtered IEC receptacles contain those caps.

Jon
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