Abstract: The invention relates to an arrangement for indicating a fault in an electrical machine having a stator and a rotor with an air gap between it and the stator. In order to detect impurities or similar objects entering the air gap, a means of supervision is arranged on the stator surface facing the rotor. The means of supervision is at least partially protruding from the stator surface, and the integrity of the included detection element, such as a copper wire, is established using a supervision circuit connected to the detection element.

Abstract: The invention relates to an arrangement for indicating a fault in an electrical machine having a stator and a rotor with an air gap between it and the stator. In order to detect impurities or similar objects entering the air gap, a means of supervision is arranged on the stator surface facing the rotor. The means of supervision is at least partially protruding from the stator surface, and the integrity of the included detection element, such as a copper wire, is established using a supervision circuit connected to the detection element.

Abstract: The present invention relates to a squirrel-cage induction motor for frequency converter use, in particular, which squirrel-cage induction motor comprises a stator, a stator winding arranged in its axial grooves, divided into at least two coil groups for each phase of the supplying alternating current and connected to the supplying alternating current in such a manner that the sum of basic frequency groove currents is substantially zero at each moment. In accordance with the invention, one half of the coil groups of each phase is connected to the supplying alternating current at one end of the stator and the other half of the coil groups of each phase at the other end of the stator.