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Re: Power Transformers
In a message dated 96-11-08 00:41:03 EST, you write:
<<
I have a 2 kVA, 10 kV power transformer that I would like to use with my new
tesla coil. This will be the first time I will be using a transformer
without
internal regulation. Are series inductors a good way to limit unput current
surges? If so how do I size them, and where do I get them.
>>
If you have been following this list for a while, you probably know that most
folks using pole pigs in the 5 to 15 kva range use arc welders as a variable
inductor to limit the pole pig current. I have a 5kva pig and the welder
works well but is probably overkill regarding its size, I have never seen it
even get warm. With a 2 kva transformer, you shouldn't need anything as
large as an arc welder although it should work ok if you have one. We were
talking about building a variable inductor at one time and think we decided
on a range of 5 to 25 mh as the appropriate size - and of course the
conductors need to be able to carry the full primary current easily. Your
transformer at 2kva will draw about 9 amps from the 220 volt line. You
should be able to push this to 4 kva or about 20 amps for short periods
without hurting it at all. If you don't have access to a welder, you
probably need to wind an inductor in the 10 to 20 mh range with variable taps
to select the current range you want. You might also use oven elements in
series or parallel with your inductor to smooth out the current.
Ed Sonderman