Like the capacitor motor, the three-phase motor is an asynchronous motor. Like this, it has a squirrel-cage rotor in which a torque is generated by means of a rotating field generated by the stator. Unlike capacitor motors, the three-phase motor is supplied by three-phase AC current (3~ 400V / 50 Hz).

Since the 3 phases (L₁, L₂, L₃) of the three-phase system are out-of-phase in relation to one another, a rotating field can be generated by respective wiring of the motor windings with the individual phases.

Three-phase motors can be wired up in two different ways: with star-shaped or triangular circuitry. The series-production models of three-phase motors included in ZEITLAUF^®'s standard range are supplied with triangular circuitry. In this case, every stator winding is connected with two of the three phases. The voltage of each phase (L₁, L₂, L₃) on its own is 230 V – this results in a voltage of 400 V between the individual phases on account of the phase displacement.

The direction of rotation on the three-phase motor can be reversed by exchanging two phase strands. (e.g. L₁ to L₂ and L₂ to L₁). Speed regulation is possible using a suitable frequency converter.

The lower weight, higher start-up torque and the fact that a capacitor is not required are clear advantages of three-phase motors over capacitor motors. The typical smooth running, maintenance freedom and long service life associated with asynchronous motors have led to a wide application spectrum.

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