Creepage and clearance calculte widht slot

[Juan]

Hi:

I have a question about the creepage and clearance, how i can calculate the width of the slot on pcb to reduce the creepage distance,I have read the minimun distance shall be >1mm, but this is confuse for me because i am not sure what standard is used to calculate this parameter or i don't have found it in IPC2221a and EN-60664 , for example in a PCB with 800V DC according at the table of the EN60664, with a pollution degree 2 i have to applly 4 mm, if i want to reduce the creepage with slot, what is my slot recomended, how is calculated this measure?

Thanks in advance

[robertferanec]

Anyone can help? Not my area

[Ashish1710]

Use a ruler or measure in 3D-model.

Software can only give you clearance distance (smallest separation between two copper objects). As creepage is the distance over surfaces, it is not always as easy to calculate, so no easy way to measure it... I tend to draw a polyline and use the length of that if the surface is flat, this suffices for most PCB's.
Creepage is always greater than clearance so either leave enough gap to satisfy the creepage requirements, where this is not possible (between connector pins) you can add a slot 1mm or wider to increase the creepage distance.

Creepage is creepage and is dependant on the specification you are working to, there is no working creepage... and don't quote figures, again creepage depends on the envoironment the PCB is going to be subjected to, as creepage is a tracking voltage, surface pollutants come into play, you are quoting clearance distances.

[Juan]

Thanks for the response

Best regards