Hi everybody,
             A suggestion on this....

> I have 2 12KV transformers.  They are about 2.5' cubed and filled with oil.  
> I 
> have been able to tell the output voltage by placing 10VAC on the input and 
> measured 1200VAC on the output.  The tricky part is how to tell what the powe
> r 
> rating is.  There is no indication of who made them or any stickers or plates
>  on 
> them of any kind.
> Does anyone have any ideas on a semi-easy way to tell what the maximum safe 
> power output of the transformers are?

Connect a capacitor across the secondary of one of them, connect a LOW 
impedance signal generator across the primary, then use a scope 
connected across the capacitor and secondary to find the resonant 
frequency. If you don't have an oscilloscope, you find resonance
easily enough by connecting a neon bulb across the 
     Knowing the value of C and f, calculate Xc by

     Xc = 1/(2xPIxfxC)
     This value will be = to Xl of your transformer. Since you know
that V = 12kV, you can calculate I = V/Xc  which you can then
calculate a ballpark W = VxI from. You can also calculate W = V^2/Xc.
I think this should get you pretty close.