Operating circuit with slow-down time relay

In some factory workshops that require continuous operation and cannot have power outages, backup diesel generator equipment is automatically put into use when the power grid fails. This requires the motor to be able to restart itself immediately. The circuit shown in the figure is suitable for restarting the electric motor after a power outage. In some factory workshops that require continuous operation and cannot have power outages, backup diesel generator equipment is automatically put into use when the power grid fails. This requires the motor to be able to restart itself immediately. The circuit shown in the figure is suitable for restarting the electric motor after a power outage. After pressing the start button ST, the AC contactor KM is closed, the intermediate relay K and the time relay KT are successively closed, and the motor M works. If a power outage occurs at this time, K will be released immediately, and the coil of KT (slow-down time relay) will be powered off, but its delayed opening contact will be delayed. If the power supply is restored while the contact KT is not disconnected, without pressing the ST start button, the power supply will delay the disconnection of the contact KT, the normally closed contact K of the intermediate relay, the stop button STP and the thermal relay contact FT, the contactor KM is closed again, and the motor M starts and runs again immediately. When parking, the stop button STP must be pressed, and the pressing time must exceed the KT delay time, otherwise it will start again.