i know that static capacitors are used to improve the power factor. power factor should be high.
Static capacitor supplies lagging reactive power.
That means;
the current I has 2 components they are magnetising Im (watless or waste current) and useful current Iw.
Iw is in phase with voltage and Im is 90 degree away.
Phase angle between them is phi 1. power factor is given by cosine of phi 1.
phi angle should be less so that cosine of phi is high.
To make phi angle less we use capacitor; this is nothing but power factor correction and capacitor used for this is called power factor correction capacitor.
now when a capacitor is connected, it induces a current Ic 180 out of phase from Im and less in magnitude from Im.
therefore, now the magnetising current is Im1=Im-Ic.
due to this the phase angle reduces to phi 2. now the new power factor is cosine of phi 2.
it is improved power factor.
The primary reason for a capacitor bank in an electrical substation is for power factor correction. There may also be some secondary purpose for the capacitor bank but the primary reason is power factor correction.
how to connect power capacitor with 3 phase motor
A power factor capacitor is a power capacitor. I'm not sure what you mean by "regular". There are different types, made from different materials that have better/worse characteristics than others depending on the application. You could use any high power capacitor for power factor correction, as long as it is sized correctly for the load and voltage.
Capacitor is connected parallel to the line which serves as power factor correction, increase line efficiency, voltage stability and reduced line losses and voltage drop.
Capacitors designed to be used for power-factor correction are rated in reactive volt amperes, rather than in farads.The reason for this is that in order to determine the necessary correction, a load's existing reactive volt amperes is first calculated, then the reactive volt amperes of the capacitor must be determined in order to achieve the required value of power factor. In other words, the capacitance (in farads) of the capacitor is irrelevant to the calculation.
Power factor correction is normally done with a single capacitor bank. If the PF fluctuates due to a change in load, the best solution is to design and fit power factor correction capacitors at each individual reactive load that may start or stop during normal operation. Connect the PF correction directly accross the load, such that when the starter or disconnect is open, the load AND the capacitor is removed from the line, and when the disconnect is closed, both the load AND the PF capacitor is energized. Continuous loads can still be bulk-corrected with a capacitor bank, this will minimize the number of individual correction capacitors you will have to design. If properly done, your PF can be made to be very stable, with little change as the load varies.
A.C capacitorAnswerGenerally speaking power-factor capacitors are oil-impregnated paper capacitors -i.e. capacitors whose dielectric is manufactured from oil-impregnated paper. Power-factor capacitors are rated in reactive volt amperes, rather than in farads.There is no such thing as an 'AC capacitor', as all capacitors (other than polarised capacitor) can operate on either AC or DC.
Power factor characteristic in a capacitor is a measurement of how efficiently a capacitor uses electrical energy.
in case of inductor or capacitor power factor is always zero.as power factor is cosine of phase angle between voltage and current. in case of inductor and capacitor phase angle between voltage and current is 90 so it become zero so if given power factor is zero then it can be inductor or capacitor.
Co efficient increasing/degreasing the contact circle is the correction factor in gear.
If the air conditioner has both, the run capacitor is likely the largest one. The start capacitor will only be in the circuit for a very short time, so overheating doesn't become an issue. The run capacitor must be sized for continual use.
I assume that you are asking how to calculate the 'value' of a capacitor? Well, it depends what it is used for. If, for example, it is used to improve the power factor of a load, then it is first necessary to determine what the load's existing reactive power is; then, you need to know what reactive power is necessary with the power factor at its desired value; finally you need to difference between the actual and the desired values of reactive power -and this will be the necessary value for the capacitor. Power factor correction capacitors are rated in reactive volt amperes, not farads.