Interferance/supression capacitors across 230Vac Line on SMPS

[[email protected]]

Any input please. The switchmode i have at the moment completely fails
it's mains leakage test (using a PAT4 tester) because of residual
current leakage to earth (through the 0.047uF/275V Wimas) of 4.3mA.
These capacitors have been in use on the aged SWPS for up to 12yrs
constantly so is it possible they will have broken down minimally
(although the 4.3mA is probably acceptable as a leak for this kind of
application). On the other hand, is there a more prefered type
supresssion device today, perhaps ex RS Components?. Thanks... pete

 

[Eeyore]

Any input please. The switchmode i have at the moment completely fails
it's mains leakage test (using a PAT4 tester) because of residual
current leakage to earth (through the 0.047uF/275V Wimas) of 4.3mA.

Yes it will do.

That's why 2200 or 2700pF is a very popular value for Y caps !

Graham

 

[Eeyore]

Any input please. The switchmode i have at the moment completely fails
it's mains leakage test (using a PAT4 tester) because of residual
current leakage to earth (through the 0.047uF/275V Wimas) of 4.3mA.
These capacitors have been in use on the aged SWPS for up to 12yrs
constantly so is it possible they will have broken down minimally
(although the 4.3mA is probably acceptable as a leak for this kind of
application). On the other hand, is there a more prefered type
supresssion device today, perhaps ex RS Components?. Thanks... pete

In case I wasn't clear - those caps are simply too big.

If you reduce their value the RFI will be worse but maybe you can live with it ?
If there's room fit a self-contained filter.

Graham

 

[[email protected]]

In case I wasn't clear - those caps are simply too big.

If you reduce their value the RFI will be worse but maybe you can live with it ?
If there's room fit a self-contained filter.

Graham

Thanx Graham

Will try some 2200pF and see what their mains leak is and then check
any RFi issues..