Bypass capacitor on ac lines help?

[milen007]

i saw my cyrus psx has very small value bypass caps (68nF) on IEC connector. what do you guys think on this.

will this help on bypassing power cable on both leads with 0.47uF as sold by Chris VD in his website? it has the risk on catching fire. how do we tackle this?

anyone use this bypass caps successfully improve performance? any opinion on this matter greatly appreciated. thx Erwin

[Sonusthree]

Do you mean PSX or PSX-R ?

[AndrewT]

Hi,
one must use Xrated and Yrated capacitors in the appropriate locations on the mains side. Fire (and safety) is then not an issue.

Be very careful to understand what you are proposing, particularly in regard to Earth Leakage Current.

[milen007]

Originally posted by Sonusthree
Do you mean PSX or PSX-R ?

I think its psx-r. Sorry typo

Originally posted by AndrewT
Hi,
one must use Xrated and Yrated capacitors in the appropriate locations on the mains side. Fire (and safety) is then not an issue.

Be very careful to understand what you are proposing, particularly in regard to Earth Leakage Current.

hi AndrewT, what do you mean by earth leakage current? There is current in ground terminal? Where to find more info on that? Thx

Another thing. My main voltage is 240v. Should get x2 cap 250v and higher? How bout auricap? 1000v enough?

[Tweeker]

There will be current in the ground terminal if you stick a capacitor from hot to it (Y service). How much current is contingent on the capacitance.

[AndrewT]

Originally posted by milen007
what do you mean by earth leakage current? There is current in ground terminal? Where to find more info on that?

Another thing. My main voltage is 240v. Should get x2 cap 250v and higher? How bout auricap? 1000v enough?

if one does not know what one is doing then don't muck about with mains voltage.

Is the 1000V Auricap Xrated or Yrated?
If it's not then don't even think about adding it to the mains side of the supply.

[milen007]

Originally posted by AndrewT
if one does not know what one is doing then don't muck about with mains voltage.

Is the 1000V Auricap Xrated or Yrated?
If it's not then don't even think about adding it to the mains side of the supply.

good idea. lol just wanna learn more. i wont touch anything unless i am sure bout it. i have basic in electrical safety but zero on circuit. any help will be appriciated.

not sure about the x or y rated. just know that auricap i am after is rated 1000v, i think its dc. as someone mention about using 600v for auricap tweek in us that has 110v. someone correct me if im wrong

Tweeker, what appliances that has cap connected to the ground? most appliances?

[gareth]

The little cap is probably an X-type capacitor. These particular type cap's tend to sit across the live and neutral of the incoming mains voltage supply and they help with EMI and RFI interference suppression.

As Andrew T has pointed out you need to make sure that you use the correct type because of possible earth leakage currents. X-type caps sit across the live and neutral whereas Y-type are generally connected together in series, two of them, and then placed across the live and neutral. Often the two types can be found working together with an inductor to bring better attenuation still.

When you buy some new ones try to find them with at least twice the working voltage if you can. You can find 400v caps pretty easily too. This is to help protect you (the capacitors) from insulation breakdown and is a wise move.

Gareth

[milen007]

Hi Gareth, thanks for the explaination, so how bout the normal vdc rating cap? are they x or y rated capacitor?

how to determine x or y rated capacitor?
then whats category are the VAC rated capacitor? any link for more info? thanks

[AndrewT]

http://en.wikipedia.org/wiki/Filter_capacitor

http://my.execpc.com/~endlr/line-filter.html

http://www.lcr-inc.com/xandy-suppres...apacitors.html