General > General Technical Chat
High Voltage insulating resin
(1/5) > >>
xzswq21:
Hello
I want to use a high voltage insulating resin for several high voltage transformers (10kV and 20kV and above) but I don't how I should choose a proper resin:






Thanks
David Hess:
Wax may be an easier to use alternative.  There are specific was formulations intended for potting.
TimFox:
With any potting material, be careful to eliminate bubbles from the final state.  Normally, this is done by pumping a vacuum above the "pot" while the material is still liquid.
Wax is a traditional material:  note that it shrinks drastically at the phase transition between liquid and solid as it cools.
T3sl4co1l:
Beats me.  Have you checked mfg websites (e.g. 3M)?

As I recall, the stuff used in FBTs is extremely hard; probably mineral filled (silica or otherwise?).

And yeah, you definitely want a vacuum pot for that.  You can verify quality in a couple ways, like hi-pot for isolation barriers, but also partial discharge for breakdown around windings -- a pocket of air exhibiting breakdown, is detectable as high frequency (impulsive) emissions, when the part is excited (preferably by a nice smooth sine wave).

Tim
David Hess:
One reason I would avoid random epoxy potting compounds is that some have horrible dielectric loss even without leakage.  Tektronix had a horrible time with this when they initially changed from wax to epoxy.


--- Quote from: TimFox on August 04, 2021, 05:02:59 pm ---Wax is a traditional material:  note that it shrinks drastically at the phase transition between liquid and solid as it cools.
--- End quote ---

That is why I mentioned that there are specific wax mixtures used for potting.
Navigation
Message Index
Next page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod