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Re: More Tuning/Debugging

> Maybe, maybe not. I opted to go ahead and purchase a single bushing
> 25 KVA 7200-120/240v pig to match my first. The price was a bit more
> than I would have liked, but this way I was able to match core specs
> to my existing pig and not have to worry about any problems. I could
> have purchased a two bushing 10 KVA 14,400-120/240 for less, but
> another thought entered my mind: I am a balance fiend, and the 50KVA
> of inductance in my lab will match the 50KVA of inductance on the pad
> that supplies our little corner of the neighborhood. Also, I actually
> like the feel of the heavier cores (provided they are not run while
> saturated) when coiling. They add a sturdy feel to the system, the
> coil does not "pull" the power supply around, and they are efficient
> enough that the idle current at the rated voltage is not noticeable
> in my controls. Space is not really a problem, I have a sturdy engine
> cart that will carry two cans and rolls around easily enough. Total
> weight will be 750 pounds.
> 
> Soooo. A good chunk of my check, not to mention my August bonus, went
> out in the mail earlier today...
> 
> Richard Quick
> 
> ... If all else fails... Throw another megavolt across it!
> ___ Blue Wave/QWK v2.12

Congrats on the pending new addition to your family of pigs! You also
still have your 23 KV beast don't you?  Your last post brought up an
interesting thought. After getting my pig (a 10 KVA, 19.9 KV animal that
stands 44" high including the 11" HV bushings and weighs 350 lb.), I've
noticed that the physical size of these things don't seem to correlate
very well with the KVA rating. My wife complains that I keep on looking
up at utility poles while I'm driving, but my limited research has
revealed that pigs in a housing the size of mine run up to at least 75
KVA with no fins (!), and smaller ones I've seen run up to at least 50
KVA. The weight of your 25 KVA animals sounds like is about the SAME as
my 10 KVA beast. 

When I was talking with the folks at Solomon, I was originally looking
at getting two 5 KVA transformers, foolishly thinking that each would be
smaller and easier to move rather than a single 10 KVA beast. They
informed me that there was very little difference in physical size or
weight between the two sizes, and that 10's were more readily available.
As a result, I opted for a single 2-bushing pig, which was about 50 lbs
heavier than their 10 KVA 14.4 KV pig. In listenning to your description
of the 25 KVA pig, I'm beginning to wonder if Solomon may have
"underrated" the KVA of my refurbished pig - I asked for a 10 KVA and
they sent me one with a big "10" painted on the case. Since I had to
wait a while, they may have custom wound the "primary" to provide the
19.9 KV output. But it weighs about the same as your 25 KVA animal -
could this be added weight of insulation(?). I've also heard in a
previous post by someone that 10 KVA's are basically "throw aways" in
the distribution transformer business.

I sure would think that a 25 KVA transformer would have MUCH more iron
in it than a 10 KVA. I also would also have thought a 75 KVA transformer
would be in a significantly larger case (maybe even with fins) than the
one I have. It now makes me wonder if I should have spec'ed a larger KVA
rating since it seems that the cost, size, and weight is about the same,
and TC performance MAY be more stable. Maybe I really have a 25 in
disguise(?)!

Any pig experts out there that can shed light on this?? Inquiring minds
want to know! :^)


-- Bert --