Capacitance

With six outlet ends of the winding engine is two nominal voltages: 127/220 V, 220/380 V. If the voltage is equal to the nominal voltage of the motor, ie Uc = 220 V at rated voltage 127/220 V or 380 V UC = under rated voltage 220/380V and so, we must use the circuit shown in Fig. A, b. When supply voltage is equal to the smaller rated motor voltage, you should use the circuit shown in Fig. 1,. In this case, a single-phase inclusion significantly reduced engine power, and therefore appropriate to apply the scheme with a working capacity.

Capacitance Cp (uF) for each scheme should have a definite value and can be calculated on the basis of a single-phase voltage Uc network and the rated current If in phase three phase: Cp = kIf / Uc where k – coefficient depending on the connection scheme. At 50 Hz for the schemes in Fig. 1b and 2b, we can take k = 2800; for the circuit in Fig. 1, – k = 4800; for the circuit in Fig. 2, – k = 1600.

The voltage on Uk capacitor also depends on the circuit on and voltage. For schemes in Fig. A, b, it can be assumed to be line voltage for the circuit in Fig. 2b – Uk = 1,15 Uc; for the circuit in Fig. 2, e-Uk = 2Uc.Nominalnoe capacitor voltage should be equal or more larger than the calculated values. It must be remembered that the capacitors after shutdown for a long time keep the voltage at its terminals and provide the touch them a risk of human electric shock. Danger is higher, the more capacity and higher voltage on the capacitor is switched into the circuit. When repairing or debugging engine to turn off after each capacitor discharge. To protect from accidental contact during operation of the motor capacitors must be rigidly secured and fenced. Starting resistance Rn is determined empirically, using the adjustable resistance (rheostat). If necessary to obtain increased torque when the engine is started, then parallel to the condenser include start-up. Its capacity is usually calculated from the formula C = (2.5 to 3) Cp, where Cp – Run capacitor. Starting time this gives a nominal time of close to three-phase motor. I hope the information has been useful for you. If you want to buy a motor for general industrial, household, you can always Companies do have electric motor.