In the inverter start delay circuit, most of the thyristor (thyristor) circuits used can cause the delay resistor to burn out when it is not conducting or performing poorly. Next, let everyone know about the knowledge of starting the precautions. I hope everyone can read it carefully.
1. The input 6kV power supply high voltage switch of the equipment must be turned on when the “high voltage closing permission” signal given by the inverter is required;
2. If the inverter does not provide the “high voltage closing permission” signal, please confirm whether the control power is closed, the cabinet door is closed, the bypass cabinet isolating switch is in place, whether it is in fault state, and related to the equipment. Whether the system signal is correct;
3. After each 6kV high voltage switch is disconnected, it must be re-powered after at least 160 seconds;
4. When the bypass switch is in the variable frequency position, the user 6kV high-voltage switch is only equivalent to send power to the inverter, and the motor does not start. Need to start the motor, you must also send a running command to the device;
5. Before starting, the fan baffle or the pump outlet valve is preferably in the closed position. And confirm that the motor is not reversed due to the baffle or outlet valve is not strict and other reasons, otherwise it will easily cause over-current shutdown when the equipment starts;
6. When the inverter needs to be started, if the fan or water pump has just stopped, it should be confirmed that the fan or the pump has completely stopped, otherwise it will easily cause the unit to overvoltage when the device starts.
7. DCS can only send a start command to the device after it is in the remote control state and obtain the “request run” signal at the same time.
8. After starting, automatically accelerate the motor to the given speed of DCS. If the given speed of the DCS is less than the minimum speed setpoint at that time, it will operate at the lowest speed.
After the DCS sends a start command to the inverter, if the given speed of the DCS and the minimum speed setting of the device are both 0, the motor will still not rotate. At this time, the DCS must set a reasonable speed setting value.