Calculator for container working and starting capacitors
When connecting single-phase induction motor in network 220/230 is necessary to provide a phase shift to the stator windings to make an imitation of the rotating magnetic field (VMP), which causes the motor to rotate the rotor shaft in its connection with the "native" three-phase AC. Known to many who are familiar with electrical engineering, condenser ability to produce electric current "head start" on π / 2 = 90 ° compared to the voltage, providing a good service, since it provides the necessary time, it is caused to rotate the rotor in the already "not native" networks.
Calculator for operating and starting capacitors
But the capacitor for this purpose should be selected, and must be done with great precision. That is why the readers of our portal is available in the absolute gratuitous use calculator for calculating the working capacity and the starting capacitor. After the calculator necessary explanations will be given for all of its items.
Calculator for container working and starting capacitors"Calculate the capacity of the working and starting capacitors""Star""Triangle"P - power motorU - supply voltage, VPower factor, cos(Cosφ)Motor efficiency, η
The following relationships were used to calculate:
|Connecting the "stars"||Run capacitor - Wed|
|Cp = 2800 * I / U; I = P / (√3 * U * η * cosφ); Cp = 2800 * P / (/ (√3 * U² * η * cosφ).|
|Connecting the "triangle"||Run capacitor - Cp|
|Cp = 4800 * P / (/ (√3 * U² * η * cosφ).|
|Starting capacitor for any connection method Cn = 2.5 * Cp|
|Explanation of symbols in the formulas: Cp - the working capacity of the capacitor in microfarads (pF); Cn - Starting capacitor in microfarads; I - current in amperes (A); U - the line voltage in volts (V); η - efficiency of the engine as a percentage divided by 100; cosφ - power factor.|
Data obtained from the calculator can be used for the selection of capacitors, but it was such denominations as will be calculated, they are unlikely to be found. Only in rare exceptions may be coincidence. selection rules are as follows:
- If there is a "direct hit" in the nominal capacity that exists in the required series of capacitors, it is possible to choose exactly this.
- If there is no "hit", then choose the capacity, standing below on a number of denominations. Above is not recommended, especially for workers capacitors, as this could lead to an unnecessary increase in operating currents and overheating of the windings, which can lead to inter-track circuit.
- Voltage capacitors are selected with par value of not less than 1.5 times greater than the supply voltage, as at the time of start-up voltage at the capacitor terminals is always high. For single-phase voltage of 220 V the operating voltage of the capacitor must be at least 360 V, but experienced electrician always advised to use 400 or 450, as the stock is known to be "no sore".
Here is a table with ratings of workers and starting capacitor. As an example, the capacitors and CBB60 CBB65 series. This polypropylene film capacitors, which are most often used in connection diagrams of induction motors. CBB65 series CBB60 different from, the fact that they are placed in a metal case.
As used launchers CD60 nonpolar electrolytic capacitors. They are not recommended for use as working since a long time, their work makes their lives less long .. In principle, suitable for start-up and CBB60, CBB65 and, but they are at equal volume tanks more dimensions than CD60. The table shows only the examples of the capacitors, which are recommended for use in connecting electric circuits.Select the capacity of the second capacitor
Is it possible to connect a three-phase asynchronous motor in a network of 220 V?
Usually, this operation is trusted only electricians with practical experience. However, you can connect the motor and himself. This article proves our portal: "How to connect the three-phase motor in the 220 Network."