摘要 |
PURPOSE:To prevent a brake shoe and a motor form burning out by stopping the energization of the motor when the motor current increases at the prescribed value or higher. CONSTITUTION:A drive motor M of a man conveyor is connected through contacts 1a-1c or 2a-2c with AC power sources R, S, T, and normally or reversely rotated. A current to the motor M is detected by a current transformer 8, and converted into a voltage by a current/voltage converter 9. When the output voltage value of the converter 9 increases at the prescribed value or higher, contacts 1a-1c or 2a-2c are opened by a voltage relay 10, the energization of the motor M is interrupted, and a brake due to an electromagnetic brake is simultaneously applied. |