Safety capacitor (in smps) - are there a proper symbol to use in drawing [solved]

[Grossel]

Hi.

Those safety capacitors used in poer supplies, does one always use the same symbol in schematic as regular capacitors or are there used other symbols in some cases ?

I'm just wonder, because I thinking one may want to visually see the difference (other than the component ID start with FB instead of C).

 

[eTech]

No, there is no special symbol.
But you should place a note on your drawing to indicate that a capacitor is a "safety" type capacitor. Also specify its "class".

Example:

Notes:
1. C1 is type Class-X safety capacitor.

You can also place an electrical shock symbol next to a portion of a circuit, bound by a dashed line, to indicate a potential shock hazard.

This way you give the reader multiple opportunities to note the hazard.

 

[Nigel Goodwin]

If you have a look at this (fairly old) circuit, everything to the right inside the solid black line is live to the mains, and thus dangerous. C53 is marked as class X, because it's across the mains, but C62 and R68 at the bottom right are inside a dashed line box, indicating they are extremely crucial safety components - as they connect the live mains to the 'isolated' metal chassis of the receiver (to provide static discharge). If C62 in particular went S/C it would be extremely dangerous - R68 is to discharge C62, and isn't likely to go S/C anyway.

 

[Grossel]

Thanks.

Then I'll proceed uing text notes like that.