| 摘要 |
<P>PROBLEM TO BE SOLVED: To interrupt power supply with a simple configuration by detecting an overvoltage applied, even with respect to a load of high electric power consumption. Ž<P>SOLUTION: A first relay contact 14b is connected between a polyphase power supply 12 and a compressor 16, and a first relay coil 14a for controlling open/close of the first relay contact 14b is provided in a control circuit 100, which consumes electric power less than the compressor 16. A second relay 140 is connected between the polyphase power supply 12 and the control circuit 100. When an overvoltage detecting circuit 22 detects overvoltage, a relay driving portion 24 controls the energization of a second relay coil 140a in the second relay 140, causes interruption operation, and interrupts power supply from the polyphase power supply 12 to the control circuit 100. When the power supply to the control circuit 100 is interrupted, the power supply to the first relay coil 14a is also interrupted; and the first relay contact 14b performs the interruption operation. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
