Cracked/exploded Evox Rifa Metallized Paper X2 Capacitors - What Deficiencies?

[wrenchone]

Those old Rifa caps are metalized paper - they can be replaced with either polyester or polypropylene units of equivalent value. Appropriate safety rating is probably X2. The usual distributors should have them. Be generous with the voltage rating, and they will last longer.

 

[bohrok2610]

BTW I've hade many mains rated X2 capacitors lose their capacitance in triac controllers due to corona effect.
The failure mode is described e.g. here.

 

[bucks bunny]

BTW I've hade many mains rated X2 capacitors lose their capacitance in triac controllers due to corona effect.
The failure mode is described e.g. here.

These are the "self-healing" X-cap while these old Rifa were the "self-exploding" caps.

 

[tiefbassuebertr]

It looks fine but shows as out of stock for me. These caps are not critical apart from having to be safety rated.

You can just snip the old one out for now, it doesn't need it to work. M can mean 20% tolerance (not critical here) and MP could be Metalized Polyester (the type).

https://cpc.farnell.com/vishay/bfc233620103/capacitor-class-x2-0-01uf/dp/CA07137

what about the currently available "RIFA" branded successors from KEMET regarding reliability and life time ?
https://electronics.stackexchange.com/questions/437683/rifa-pme271m547-replacement

 

[bucks bunny]

I suspect current Rifas/Kemet are better know, but why should I test them as long as I trust Epcos.

 

[tiefbassuebertr]

A friend told me, that there was a web address with all brands and models of vintage audio devices that used this series of Rifa capacitors.
Unfortunately, this URL don't currently exists.
Who knows the exact address of this old URL?
Maybe this page can still be reached via the web archive.
Thanks for an information.

 

[wg_ski]

These are the "self-healing" X-cap while these old Rifa were the "self-exploding" caps.

Wasn’t Rifa part of PHILIPS back then? I have some old Rifa/Philips branded CG’s that every single one of them developed a bad (dried and cracked) rubber seal. I’m hesitant to use them…..

Goes back to what we say about Philips….. That funny symbol of theirs is supposed to be radio waves going through the “ether”. But it also looks like three of the “elements” - Earth, air and water. Fire happens when you plug it in.

 

[bohrok2610]

Rifa was part of Ericsson until 1988 when it was merged with Evox.

 

[tiefbassuebertr]

check out this URL:
https://hackaday.com/2023/04/01/why-do-rifa-capacitors-fail/
and this thread because this capacitors also in use in the potted versions in IEC C14 mains inlets as integrated part.

Thread 'Blown X2 Cap in Mains Inlet RFI Power Filters (IEC C14, Schaffner, Schurter and others)'

2024-12-12 6:31 pm

Several components for hifi/home audio in used condition are danger even outside of operation, because the integrated capacitors in the mains inlet C14 plugs are not disconnect from mains after switch off the component (and not to check and for replace).
Therefore the aging is more extend and it is not possible to check the condition like describe under
because the parts are potted and thus not accessible without destroy.

A friend of me observe such...

• tiefbassuebertr
• Replies: 23
• Forum: Power Supplies

 

[bucks bunny]

Many words and little information in that video.
No real explanation imho.
Personnally I suspect voltage surges on the mains being the reason,
self-healing not working properly.
so it would be interesting to do a surge test with peak voltages of several kV and monitor for any capacity loss during tests.

 

[thermionic]

Plenty of gags in the comments section: "Smoking a RIFA"