Topic: Snubber caps or safety capacitors questions

[qguy]

A ceramic capacitor on my amp failed, its a capacitor connected across the AC power switch. I need to replace it, I was advised to get this

http://ca.mouser.com/ProductDetail/Cornell-Dubilier/104M06QC100/?qs=N93jU/OIph6DEMraSx0M3A==

or a  0.1µf 250V safety cap that is suitable for main use

I am pretty sure I can get this type of capacitor in our shops here, but how do I differentiate this from a regular capacitor or how do i ensure myselft that I get the correct cap for the AC switch ?

[JojoD818]

May I know how you classified the capacitor as a failed one? Pardon the question, I'm only curious on what led you to believe that it had in fact failed. Maybe it's the switch and not the cap? Just saying.

For mains use, agencies and other governing bodies insist that you only use X-Class Class 1 and Class 2 caps, no exemptions.

Your application requires what we call "spark quencher", if you'll notice the type and class of the capacitor in your link, it is a Type-Q which means it acts like an R-C snubber, the R is a resistor that lowers the Q to somehow suppress L-C ringing.

However, for general, non-critical applications, a single x-class or y-class cap with the suitable capacitance will successfully work as a spark quencher.

If you will shop locally, I suggest you bring a magnifying glass so you can read if it is indeed an x-class cap.

Good luck.

[qguy]

While Testing on DBT, the 160 watt bulb lights up even when the receiver was off, I noticed that the capacitor connected to the switch has burn marks on the plastic covering. I removed one leg of the capacitor and then tested again and the bulb is now totally dim.

Here is what is printed on the cap
E
1032
A.C.250v
7N

What exactly should be printed on the cap aside from voltage and capacitance ? (Pang volts and capacitance, lang ako and occasionally temp hehehe)

SALAMAT

[vhinx]

You can replace it with 0.1uf 450vac ceramic or (X2 & XY) polyfilm cap if cannot find the original one... Is this matter was for your monster receiver.

[JojoD818]

While Testing on DBT, the 160 watt bulb lights up even when the receiver was off, I noticed that the capacitor connected to the switch has burn marks on the plastic covering. I removed one leg of the capacitor and then tested again and the bulb is now totally dim.

Here is what is printed on the cap
E
1032
A.C.250v
7N

What exactly should be printed on the cap aside from voltage and capacitance ? (Pang volts and capacitance, lang ako and occasionally temp hehehe)

SALAMAT

Ok so it is kaput then. Your cap is a 0.01uf/250VAC Class 2. An MKP with the same value should do well. They mostly come in 275VAC or sometimes labelled "~275" or "275~". The cap should also have a print that states it's an X-Class. Normally it is printed "X2" that denotes it is an X-Class Class 2 cap.

It should look something like this but can be of different colors, usually in red, blue, green or yellow...



Don't get the black ones, if my memory serves me they are reserved for Class 3 AC running capacitor applications or something to that effect.

Happy hunting sir.

[qguy]

Vhinx, 

Yes, its for the monster receiver, I think that cap may have killed the PS section as it was drawing current 24 x 7 regardless if it was on or off.

JojoD,

thanks for your response, the picture provides a lot of help.

[vhinx]

ok, hmmm... as your previous post that this cap connected at power switch pins right, do you tried to cut any either caps pin and try to power On and check what happen? this power ac caps was a secondary safety device so can use the monster receiver even without it... or possible fault switch problem.

Same as below...

[qguy]

No other caps was disconnected when testing, besides I think that is the only cap that is connected in series with the main line.