| 摘要 |
An asynchronous machine uses a short-circuit rotor that is rotatably mounted by means of rolling bearings. Damage to the grease-lubricated bearings of the machine is prevented when the machine is started up in a temperature range below or near the freezing point by providing that: (1) before the machine is started and while the rotor is simultaneously locked, a voltage is applied, as a function of the temperature prevailing at the machine at its stator winding, of such magnitude that a current several times the rated machine current flows; and (2) when a certain temperature is reached at predefined parts of the machine or after a certain voltage application time, the current is switched off and the locking of the rotor is released.
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