Motor restart controller

Abstract

The invention discloses a motor restart controller. The controller comprises a backup power supply unit, a logic relay unit and an output relay, and the output relay stores energy and supplies power to the backup power supply unit and provides an output contact; when the logic relay unit detects that the contactor normally-open auxiliary contact or the frequency converter operation signal contact is disconnected, if the logic relay unit detects that the power supply voltage instantaneous sinking amplitude reaches a preset amplitude before the contactor normally-open auxiliary contact or the frequency converter operation signal contact is disconnected, the power supply voltage instantaneous sinking amplitude reaches a preset amplitude; and if not, the logic relay unit controls the output relay (excited), and the action mode of the logic relay unit is shown as instantaneous closing of the output contact.

Description

technical field [0001] The invention relates to the field of motor restart, in particular to a motor restart controller. Background technique [0002] At present, AC contactors and frequency converters are commonly used in modern industrial low-voltage motor control circuits. Its characteristics are self-maintaining when charged, and release without pressure. However, when the motor encounters a momentary power loss during normal operation, it will cause the release of the contactor and the low-voltage protection trip of the frequency converter. When the power is automatically restored, manual re-operation is required to resume the motor operation, resulting in unnecessary shutdown of the motor during operation. In order to avoid this situation, the motor restart controller adopts the method of connecting the controller with the contactor and the frequency converter, and collects the connection status of the contactor and the frequency converter at all times. When it detects...

AI Technical Summary

Problems solved by technology

But the disadvantage is that it is a malfunction within the preset time period. If it is really artificially stopped or tripped due to a fault, the car will not be able to stop because the start command is blocked within the preset time period, causing hidden dangers of failure.

Because there is no further judgment on the cause of its release and tripping, it is directly treated as power supply voltage swaying, and for contactor release and inverter tripping not caused by swaying, if the output contact of the backup power relay is directly closed, the locking time In the section, the motor is in an uncontrolled state, which is more dangerous in the actual production environment. For example, when the motor fails and stops, the contactor will be released and the frequency converter will trip. Therefore, there is an urgent need for a motor that is both safe and fast in response. restart device

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