I’ve done a little bit of research and I can’t find any source that has the voltage breakdown of plain vegetable oil.
Maybe I missed something somewhere but I could use some help on this. Or a different point of view.
Electronic – the breakdown voltage of vegetable oil
high voltage
Related Solutions
High voltage clearance is a complex subject. Too many factors and standards to consider.
In your case, I'd follow the IPC-2221A "Generic Standard on Printed Board Circuit". According the table 6-1. "Electrical Conductor Spacing" for a 80V difference between conductors we have:
Internal layers --> 0.1mm (3.9 mils)
External layers uncoated -->0.6mm (24 mils)
External layers coated --> 0.13mm (5 mils)
IPC-2221A is a proprietary standard and I can´t reproduce the whole table here.
These numbers are not mandatory, they just stated a minimum clearance. I would use bigger numbers.
Note, as it´s said before, the high power vias. They should keep the clearance in the "low voltage" side.
The stackup seems to me quite sensible but keep in mind the pins in the High power THT components. They should keep the clearance.
Your power outlet has an earth contact you can use for your purpose (even if you don't use the power outlet as your power source).
It's one of those contacts that are exposed and can be touched. E.g. in this picture the two contacts at the top and bottom of each of the two Schuko outlets.
Best Answer
In the US cooking oil that is marketed as vegetable oil is typically soy bean oil. It's breakdown voltage is around 39kV according to https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.300.4963&rep=rep1&type=pdf
Canola oil is another common cooking oil in the US it has a similar breakdown voltage to mineral oil, 30kV according to https://aip.scitation.org/doi/abs/10.1063/1.5022926 pdf: https://aip.scitation.org/doi/pdf/10.1063/1.5022926
The article references Rapeseed oil this is another name for Canola oil.