Excuse my ignorance, but why would you want to insulate a transformer? I always make sure there is good safety ground attached to the core.
Yours inquisitively,
Fox, W7FOX
Well Fox, many of us have been doing that for years. Some may feel that it is not good engineering practices but this is ham radio. As an example, I just found a beautiful RCA modulation transformer that is probably 80 years old. There is no name plate rating on the voltage the winding's are rated at to the core or from primary to secondary. By mounting it above DC ground there is less a chance that it will create a current path to its core and save it from an early trip to the scrap yard
In the case of a inductor where you needed one at 1 amp at 4 KV and you don't have it, but you do have one rated at one amp at 3 KV, I would use it in the 4 KV circuit above ground.
I have a nice 11 Henry choke that is rated at 6 KV but it has leakage to the core in the order of a few meg ohms. For whatever reason, heating it up to hopefully drive out the moisture (if that is what it is) didn't work. I ended putting it in the negative lead of a full wave power supply and that solved that problem. But there is another part of the story about that inductor, it is a modulation reactor complete with spark gaps and it really a waste using it the way that I am so, one day it will come out of that service and mounted above DC ground to gain use for it's intended service.
I am sure there are many others on here that have done the same. I even heard of people just putting their iron above ground using ordinary dry lumber.
Generally speaking, high voltage power supplies are very dangerous and I just cannot see any additional danger putting components above DC ground, when one should consider that it is NEVER a good idea to stick your hand in there to measure temperature of a given component as an example. One thing for sure, I would never mount a plate transformer above ground! That could get ugly very fast!
I hope this explains this a bit more and I hope others will chime in!
Terry