A question about safety caps

[hopjohn]

I'm going through some early 70s solid state units with across line and line to ground axial electrolytic caps not like the typical round ceramic safety rated caps that I'm familiar with in the later 70's stuff. Anyway, these axial caps are rated to 800v in some cases. As a precaution I just want a second or ten opinions to be sure that a X2 250v for across the line, and a X1, Y2 250v for line to ground are appropriate here.

If there's cap/s you're fond of a mouser or digikey part number would be nice too. Thanks.

 

[elnaldo]

You are right, X2 aCROSS the line and Y2 line to ground is what you should use.

AFAIK those X2 and Y2 are tested at several thousands of volts, 4000 if I remember well.

I've seen film caps rated 600 or 630V across the line too in '70s gear.

 

[gridleakrick]

Those old axial caps are not electrolytic; they are non-polarized--usually film type but can be paper/foil in really old equipment. The 600 or 800 volt rating is their DC voltage rating (as is the rating for all caps except safety ones). Their AC voltage rating is much lower--like 200 volts AC or less. Safety caps are special in two ways--they are designed to not fail shorted and they are rated specifically for AC voltage.
Rick

 

[hopjohn]

Those old axial caps are not electrolytic; they are non-polarized--usually film type but can be paper/foil in really old equipment. The 600 or 800 volt rating is their DC voltage rating (as is the rating for all caps except safety ones). Their AC voltage rating is much lower--like 200 volts AC or less. Safety caps are special in two ways--they are designed to not fail shorted and they are rated specifically for AC voltage.
Rick

So these are film type and DC rated to 800v, though it says AC? ,,,,just some part numbering thing?
Let's not do anything to confuse people with the markings Matsushita.

 

[BinaryMike]

Those old axial caps are not electrolytic; they are non-polarized--usually film type but can be paper/foil in really old equipment. The 600 or 800 volt rating is their DC voltage rating (as is the rating for all caps except safety ones). Their AC voltage rating is much lower--like 200 volts AC or less. Safety caps are special in two ways--they are designed to not fail shorted and they are rated specifically for AC voltage.

"Designed to not fail shorted" generally means that paper/foil and film/foil construction cannot be used. Metalized paper or film is 'self-healing' in that shorts are cleared by vaporizing the metal, but these caps tend to lose capacitance over time when exposed to all the garbage on the AC line. A higher voltage rating potentially yields longer life in this application.

If the marking on a cap states an AC voltage rating, then you can believe it. The DC rating would be higher if given, but space is often limited and the cap's intended application may dictate its marking.

 

[hopjohn]

If the marking on a cap states an AC voltage rating, then you can believe it. The DC rating would be higher if given, but space is often limited and the cap's intended application may dictate its marking.

With that being said, what do you suggest as a replacement?

 

[N8Nagel]

I made a lengthy post in this thread

http://audiokarma.org/forums/index....tment-on-rebuilt-modified-lk-72.750590/page-3

Probably tells you more than you want to know about safety caps. And there's a part number hidden in there too.

 

[hopjohn]

I

Probably tells you more than you want to know about safety caps. And there's a part number hidden in there too.

Thanks @N78Nagel. Mouser had your part on order so I did some sorting on that same series of caps. I found one that was identical with the exception of the leads, yours kinked, the other straight (referencing page 3 of the datasheet). It being X1,Y2 rated I should be able to use it in either application (across line and line to ground) if I understand correctly.

Here's the part for verification VY2103M63Y5US63L7 Look good?

 

[elnaldo]

X1 Y2 means it can be used in both applications. It has been tested for both specs. It's a cap that won't fail short and won't start a fire.

 

[N8Nagel]

yep should be good to go as long as the value is right, and even that is probably not critical. That's why I picked the one I did, mine was a line-line application but I still have a Pilot 654 and matching MPX on deck for some tweaking as well so might as well replace 'em all.

 

[floorbanger]

Hello,

I have another Trio KA2002 amp that I'm fixing currently, the safety cap (.01uf 630wv) is faulty. (Please see photo) It connects from 2 amp fuse to power supply.
Can I use the same cap in above link that hopJohn is using? VY2103M63Y5US63L7 The cap in link is 0.01uf not .01uf or can anybody recommend correct replacement please?
It's a similar cap as .01uf AC800, but is (.01uf 630wv) would this still be OK to use? Guessing it should be fine, just need to double check before installing, but the value is 0.01uf in link as mentioned, not .01uf which is the correct value.

As mentioned in above posts, safety capacitors can be a bit confusing with X1 X2 Y2. Also this safety capacitor is for UK 220-240 voltage.
Your advice is much appreciated

Thanks.

 

[elnaldo]

0.01 = .01

A 0.01uF ( or 10nF) safety capacitor is what you need. X1/Y1 or X2/Y2 will be fine.

The one in the link is X1 Y2. It will work.

Y1 is a higher spec. But for a home appliance, Y2 is OK. (You can Google what are the max voltages those capacitors can withstand)

 

[floorbanger]

0.01 = .01

A 0.01uF ( or 10nF) safety capacitor is what you need. X1/Y1 or X2/Y2 will be fine.

The one in the link is X1 Y2. It will work.

Y1 is a higher spec. But for a home appliance, Y2 is OK. (You can Google what are the max voltages those capacitors can withstand)

Thank you