What is "potential surface arcing"?

I ran into this term but havent found data on it.
Would love some explanation on it.

Thanks.

Surface arcing happens if two different level voltages use the PCB material (or any other) as medium to balance, other than air arcing.

In simple words: Connecting mains (230VAC) with a 1.27mm pitch connector on a PCB the current will mainly flow from one pin to the other using the PCB material as conductor.

Boncuk

Boncuk said:

Surface arcing happens if two different level voltages use the PCB material (or any other) as medium to balance, other than air arcing.

In simple words: Connecting mains (230VAC) with a 1.27mm pitch connector on a PCB the current will mainly flow from one pin to the other using the PCB material as conductor.

Boncuk

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Thanks, What do you mean by air arcing?

Could you tell me please what is the voltage that a lighting applies on circuit?
If a lighting occurs, it ,means that all 250Vrms voltage rating 'AC mains input' capacitor will be destroyed?

The correct term is tracking which is caused moisture and salt on a surface creating a low resistance path where an arc can easily from.

Although a sensible distance of a couple of mm is recommended between the mains conductors, it's very unlikely that you'll get the mains to arc. The only reason why this is recommended is because there can be 2kV transients on 230V mains.

The tracking distance depends on the material type, distance, air pollution/humidity and the voltage. Another thing to consider is the insulation class, i.e. whether the insulation is between mains conductors or the user and the mains. If the insulation is safety critical i.e. the gap is the only barrier between the user and the mains it needs to be much larger than between live and earth or live to neutral.