In most cases, rewinding the stator in the above example is not necessary

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The working and auxiliary windings of a single-phase two-phase motor can be obtained from a three-phase winding without rewinding.

The switching circuits of the three-phase winding are shown in Fig. 3-20.5- el. The circuit in Fig. 3-20, (3 can be made with six terminals. This gives a slightly higher starting torque. In the case where the network voltage corresponds to the phase voltage of the three-phase winding, the circuit is used

Fig. 3-20,3 (triangle). If the line voltage corresponds to the line voltage of the three-phase winding, then the circuits of Fig. 3-20, b?, g, e (star).

It should be borne in mind that the voltage on the capacitor in the circuits in Fig. 3-20 a b is equal to 1.4 U in the circuits in Fig. 3-20, (5, z is equal to the network voltage, and in circuits with a transformer it can iraq telegram data significantly exceed the network voltage. This should be taken into account when selecting the operating voltage of the capacitor (if the capacitor is intended for operation in DC circuits, then its operating voltage for operation in an.

AC network of 50 Hz should be 2-3 times greater than the voltage at its terminals. For motors with a power of up to 250-300 W and a voltage of 127-220 V, the required capacitance reaches tens of microfarads, and the starting capacitance is even hundreds (100-150) microfarads. The capacitance of the capacitor is selected experimentally based on the minimum current consumption of the windings in the operating mode or on the maximum torque developed by a stationary motor (starting power).

When rewinding three-phase motors to single-phase power supply, sometimes you have to deal with a phenomenon where the rewound motor does not start, but gets stuck at low speed.

This phenomenon is more common in bipolar motors (3,000 oSmin) and especially in the absence of conical grooves on the rotor.