Clearance and creepage in oil
Clearance and creepage in oil
(OP)
I have read few standards (only one I can think of) that specifies clearance and creep distances in oil filled equipment. All the standards I have read on medium voltage equipment (15 kV), both NA and European, specify spacing in air with no mention of oil (or other fluids). Anybody have any comments or references that will help? Seems to me both clearance and creep can be reduced, but by how much? An impulse test will be teh pass/fail for a design, but I'd like to pass the test on the first try.






RE: Clearance and creepage in oil
There is a routine test performed on oil called dielectric strength. Two different standards change the shape of the electrode.
It seems to me typical numbers are 35kv - 45kv. What is the spacing? If it is one cm, this seems like not much more than dielectric strength of air, which is 30kv. Maybe this suggests that clearance should be comparable to air?
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RE: Clearance and creepage in oil
I'm more concerned with designing to a standard, or if none are applicable, then designing based on rules of thumb or engineering experience such that I can pass electrical tests (dielectric, insul resistance, impulse and maybe PD)
RE: Clearance and creepage in oil
On the other hand, clearance of static equipment such as transformers, depend primarily of the dielectric strength of the oil and geometric of the conducting parts (electrodes). If the electrode will create arching such interrupting devices, additional consideration and clearance reduction should apply. Humidity in oil and contaminating particles also contribute to reduce the insulating strength of the medium.
Here is a graph that may be use to determine the clearance in insulated oil.
RE: Clearance and creepage in oil
RE: Clearance and creepage in oil
RE: Clearance and creepage in oil
RE: Clearance and creepage in oil
As for the space requirements under oil, it very much depends on the type of oil being used. Some oils have better insulating properties than others.
RE: Clearance and creepage in oil
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