| 摘要 |
PURPOSE:To prevent a protector from operating again by limiting the operating frequency of an electric motor at the time of restarting to such frequency that is lower than the operating frequency when the protector has operated. CONSTITUTION:If rotational frequency of a motor compressor is in an overload state, a protective circuit 11 operates, and an electric motor 2 stops, while an abnormal signal is inputted into a microcomputer 8 from the protective circuit 11. At this time, the microcomputer 8 stops output of a command frequency signal, and command frequency at that time is stored in a data random access memory in advance. If so, when the motor compressor restarts its operation after the elapse of the specified time, even if there is a demand for operating frequency increment, the command frequency of the motor 2 is limited to such frequency that it lower than the command frequency at the time of stoppage of the motor 2 being stored in the data random access memory. |
