Safety X/Y capacitors

[eccerr0r]

What are the good brand/models of safety capacitors?

What are the bad ones?

I just have a bad history with Rifa X2 capacitors as pretty much all of the cracked X2's I've ever seen are Rifas; and most people on random websites have horror stories about them...

I need to get a few 0.068uF X2 capacitors to replace ones that had their plastic crack...

[stj]

Re: Safety X/Y capacitors

new rifa's are fine - it was just the older resin that cracked with age. (a lot of age)

[eccerr0r]

Re: Safety X/Y capacitors

Kemet now owns Rifa right?

I guess I've seen so many Rifas that have cracked cases... The cracked Rifas I need to replace have are about 22 years old...

[stj]

Re: Safety X/Y capacitors

i know the ones - no case, just in a block of yellowed resin that was obviously cast in a mould.

the newer ones are a plastic box filed with an opaque white resin.

[budm]

Re: Safety X/Y capacitors

I use PANASONIC ECQUL series.

[japlytic]

Re: Safety X/Y capacitors

My favourite brand of ceramic capacitor (including safety Y-class units) is Murata, but I have yet to decide on a favourite brand for X-class units.
I've seen a number of Rifa/Miniprint X-class units go bad, especially the clear encapsulated units where the encapsulation can crack allowing moisture to enter.

[stj]

Re: Safety X/Y capacitors

we are talking about film caps

[rhomanski]

Re: Safety X/Y capacitors

Let's talk about electrolytics. The Dual CS-5000 has two Frako filter capacitors that are notorious for going bad. One of mine shorted about 8 years ago. That's what got me started on the road to here.

[eccerr0r]

Re: Safety X/Y capacitors

Hmm... I've not seen many electrolytics used as line filters...

But anyway, should paper be avoided like the plague or have they gotten 'good enough' that the catastrophic failures no longer happen? Or should we just stick with poly dielectric?

Yes, the resin ones I'm scared of. I have a crack in at least one of them my 2440.

[PeteS in CA]

Re: Safety X/Y capacitors

I've been out of the commercial P/S "world" for quite a while - ~15 years of jobs in motor control and military power supplies - but Rifa's PME271 X and Y caps used to be top end in the world of safety caps. back in the late 80s or early 90s Evox and Rifa merged, but it looks like they've been bought by Kemet.

Before labeling an established vendor's products as intrinsically bad, I'd consider the age and operating environment. Even the best parts can fail with age and stresses. A 10 year old safety cap operated in an environment with lots of thunderstorms and/or inductive surges (due to other electrical equipment) is likely to be in pretty poor shape.

[stj]

Re: Safety X/Y capacitors

that's not the issue,
the resin shrinks over the decades until it cracks - then you get moisture in the film layers

[eccerr0r]

Re: Safety X/Y capacitors

I'm still really surprised all of the X caps I've seen from late 70s to late 80s equipment that I've bothered to look at those caps are all RIFAs - which blows my mind how it got to be pretty much a virtual monopoly on these safety caps. And every single bad X cap I've seen was a RIFA. This is hinting at a bad sample but I would have figured that I've seen some other manufacturers also suffer blowouts if each of them have are subjected to similar conditions. It is indeed strange, unless as stj mentions there's a problem with the plastic.

Currently I'm eyeing Panasonic safety caps as they're...cheap... at least compared to the modern RIFAs.

[stj]

Re: Safety X/Y capacitors

old rifa's are epoxy resin,
i know a shop with a whole box of original unsold caps from the early 80's - all are now cracked!
they probably work fine because they have been dry-stored, but get them in a normal enviroment, and then put mains through them and i bet the layers will arc.

[eccerr0r]

Re: Safety X/Y capacitors

I've been putting off swapping the cracked X caps in my 2440 because the humidity isn't so bad around here. Technically speaking I have two scavenged 0.1uF X2 caps I could use to swap out the cracked 0.068uF's but choose not to ... at least for now. If they go up in flame before I get the new 0.068uF's I guess the 0.1uF's will go in.

Looking at the scavenged caps that I have, I have 5 X2 caps. They look like they all have 90s datecodes and none are RIFAs. Unfortunately I don't recognize any of the manufacturers "ERO"? "TC"? but they all have markings on them like Underwriters Labs Recognized Component marking (only two of them have Canadian Standards Association marking). Unfortunately I don't recognize other countries' safety markings, and I don't see TÜV (Germany) which I've seen before...

Ahh found another X2 cap, this one has Matsushita's logo on it. Can't discern a date code from it, and didn't see it as a safety cap initially as it was only dipped, but not potted in a plastic case.