INSTALLATION FOR DETECTING FAULTS IN SQUIRREL-CAGE ROTORS

The invention relates to a installation for fault detection control in the squirrel cage rotors of asynchronous motors, in particular for faults occurring during aluminium rotors casting, materialized as broken, narrowed or cracked bars of the cage. According to the invention, the installation consists mainly of a horizontal bearing surface (1) on which there is a fastening device (2) wherein a rotor (3) with a squirrel-cage winding to be tested is introduced, with a plate (4) made of electrically insulating material fastened on its surface, said plate being provided with a circular channel (c) in contact with the surface of the rotor, a quantity of ferrofluid (5) being deposited in the channel (c), the rotor squirrel-cage being connected to a current source (8) by means of some flexible connections fastened on some short-circuiting rings of the cage, by means of some clamping flanges with adjustable screw, so as to form, on the path of the rotor bars, some stripes of ferrofluid having a height depending on the associated current value, generating ferrofluid columns with a lower height for the narrowed or cracked bars, in comparison with the height of faultless bars.