Single-phase motor/AC motor

On this page, you will find a selection of single-phase motors, also known as AC motors, in frame sizes 63–112 with power ratings of 0.18 kW, 0.25 kW, 0.37 kW, 0.55 kW, 0.75 kW, 1.1 kW, 1.5 kW, 2.2 kW, 3.0 kW, and 3.7 kW. These single-phase motors are offered with a running capacitor and a starting capacitor. IEC AC motors are also frequently required as custom motors to meet specific customer requirements. We are the ideal partner for you in this regard, as our expert staff, combined with an extensive motor inventory and in-house final assembly, allows us to cover a wide range of needs. Whether you require a special 220 V brake motor, a circular saw motor , an AC motor with a special shaft, a special voltage, or a single-phase motor in various protection classes – we are your contact! Top quality, a competent team, and competitive pricing are our priorities. If you cannot find your 230-volt motor here in the online shop, please send us your inquiry.

The 230V motor

Our AC motors are available with running and starting capacitors. The version with two capacitors is designed for heavier starts. Our AC motors can generally be operated in both clockwise and counterclockwise directions. If necessary, only the control signal needs to be changed. For AC motors, the voltage rating has been changed from 220 V to 230 V. For three-phase motors, the rated voltage has been increased from 380 V to 400 V.

How is the rotating magnetic field generated in a single-phase motor?

Since the at least two phase-shifted voltages required to generate a rotating magnetic field are not available with single-phase alternating current, an auxiliary phase must be generated. One of the two stator windings is supplied directly from the AC mains, while a capacitor is connected in series to supply the second winding, which is positioned at a 90-degree angle to it. This capacitor causes the phase shift of the voltage across the second winding. The rotating magnetic field generated in this way is sufficient to move the rotor. However, it is also load-dependent and results in low starting torque. Therefore, capacitor-start motors should ideally be started with no load up to their rated operating speed. The starting torque can be significantly improved by briefly connecting an additional starting capacitor, approximately two to three times larger, in parallel with the existing one during the start-up phase. The higher starting current requirement, which can be several times the operating current at rated speed, must then be taken into account.

AC motor/capacitor size

Strictly speaking, the capacitor size can only be optimized for a single load case. With optimal capacitor sizing, approximately 65% of the mechanical power can be achieved compared to a similarly designed asynchronous motor with a three-phase supply. High-quality capacitors are usually used for the phase-shifting or starting capacitor. Typical capacitance values are approximately 20 µF per kW of motor power. For heavy starting loads, the capacitance value can reach up to approximately 50 µF/kW.