Capacitors Capacity

They both are different units of two different parameters,

Micro farad is the measure of the capacitance and its larger unit is farad. KVAr is the reactive power and its smaller unit is VAr.

1000 VAr = 1KVAr

10⁶ Micro farad = 1 Farad

That is correct.

Note that the KVARs rating is voltage (and frequency) dependant while the uF is fix for a capacitor.

I.e. a 10uF capacitor will be 10uF at 10V and at 100V but will have 0.377VAR at 10V and 37Vars at 100V (60 Hz).

This mean that if you use your KVAR rated capacitor at a voltage (or a frequency) different than what it is intended for, you will not get the KVARs specified.

Obviously, using any capacitors at a higher voltage than rated will lead to it destruction more or less rapidly depending on the overvoltage.

"Obviously, using any capacitors at a higher voltage than rated will lead to it destruction more or less rapidly depending on the over-voltage."
There is one exception, and that is a capacitor in a magnetic resonant circuit. The voltage will and can rise to many times the breakdown voltage but will do so without discharge. If it weren't for this phenomenon, Tesla could not have seen "the brush". He noted several times in his writing that the reason for this must be the non-movement of the electrons that would otherwise be the breakdown should they move, but because they don't move in a standing wave at resonance, the breakdown does not happen and the voltage of the system continues to rise with each cycle, beyond the breakdown voltage of the dielectrics used.
BUT, if there is a weakness in the dielectric anywhere within the resonant circuit, AND electrons begin to move, THEN BANG! The piper is paid.

I don't see how the magnetic field would prevent the electron flow in the gap between the electrodes but not within the electrodes. All I can see is that the curving of the electron path from the B-field would lengthen the effective gap and increase the breakdown voltage. But at one point, something will (most likely) break down.

"...a capacitor in a magnetic resonant circuit. The voltage will and can rise to many times the breakdown voltage but will do so without discharge. If it weren't for this phenomenon, Tesla could not have seen "the brush"

I have never heard that before. You are speaking about the man who caused the Colorado Springs power station to burn down. What is "the brush"?

Nah, don't happen. The capacitor doesn't know whether there's an inductor out there or not. It will breakdown at when the local voltage exceeds breakdown. Don't believe all that Tesla BS.

This is a common 'miss read', or taken 'out of context'

No current flow = no circuit.

You can raise the potential on an unconnected capacitor (or any component) till the cows come home (in a vacuum), or in Tesla's case, discharge into the atmosphere causes a meaningful circuit.

I.e. the 'breakdown voltage' becomes the difference in potential when current is drawn.

Oddly enough this capacitance thing applies to transmitting radio signals and such like.

!

http://www.tfcbooks.com/tesla/1892-02-03.htm