| 摘要 |
The present invention provides a motor protecting relay with a calibration coefficient self-diagnosis function which is capable of automatically diagnosing a change in a calibration coefficient. The motor protecting relay according to an embodiment of the present invention comprises: an electric quantity detecting unit which detects a current and a voltage supplied to a motor; an analog-digital converter which converts an analog signal, which represents the electric quantity from the electric quantity detecting unit, to a digital signal; and a processor which processes electric quantity detection data provided from the analog-digital converter, calculates a difference value between a preset calibration coefficient used for calibrating the electric quantity detection data and a preset reference calibration coefficient, and determines whether the preset calibration coefficient is allowable according to whether the calculated difference value falls within a preset error percentage. |
