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UA 
RU Water is a very important component in human life and in industry. It is necessary in many processes. Therefore, it is not surprising that the number of pumps supplied for extraction or pumping is constantly increasing. At a time when almost all of Ukraine has switched to blackout schedules, electric generators or solar/hybrid inverters are used to power pumps. But pumps, like any equipment containing a motor, have a considerable starting current. Usually, it reaches about 10 times the nominal value. Therefore, when powering pumping equipment from a generator or inverter, it is necessary to choose generating equipment significantly higher in power than the pump consumes. This is not economically viable because each additional kilowatt of generating capacity costs significant money. And most importantly, this excess power is needed for a very short time, up to 1 second, only at startup. But there is a solution. A frequency converter allows the starting current to be almost completely reduced to the nominal value. Thus, generating equipment can be purchased with a small reserve, significantly saving invested funds and not deteriorating the system itself, but on the contrary, adding protection for the pump motor. 1 kW of generating equipment costs 3-6 times more than 1 kW of a frequency converter. Let's consider the operation of a pump from a pressure switch as an example.
The essence of integrating a VFD into a pump control system via a pressure switch is that the automatic mode is fully preserved, but additional protective functions for the electric motor are added. We will consider the necessary set of parameters based on high-tech VEICHI VFDs. These parameters are suitable for AC01, AC10, AC310 series.
| Parameter | Description | Value |
| F00.03 | Reset to factory settings | Value 22. |
| F02.01 | Number of motor poles | Taken from the motor nameplate, or calculated by the formula 120*f/n where f is the nominal motor frequency, and n is the synchronous speed, for example, for a "three-thousand RPM" motor it is 2 poles (120*50/3000), for a "fifteen-hundred RPM" motor it is 4 poles 120*50/1500, etc. |
| F02.02 | Motor nominal power, kW | Taken from the motor nameplate |
| F02.03 | Motor nominal frequency, Hz | Taken from the motor nameplate |
| F02.04 | Motor nominal voltage, V | Taken from the motor nameplate |
| F02.05 | Motor nominal speed, rpm | Taken from the motor nameplate |
| F02.06 | Motor nominal current, A | Taken from the motor nameplate |
| F02.07 | Motor autotuning | 2. Static tuning (if it is impossible to disconnect the load). After selection, press the run button. r00-r01-r02-r03-frequency 50.00 or an error code will appear. We usually use this option |
| F01.00 | Control type | 0. Asynchronous motor, scalar control |
| F01.01 | VFD start method | 1. Start from terminals |
| F01.02 | Frequency command channel | 0. Frequency command from buttons on the panel. Usually set to 50 Hz – motor nominal frequency |
| F01.21 | Acceleration time setting | Motor acceleration time is set in seconds (usually not less than 10-15 s) |
| F01.22 | Deceleration time setting | Motor deceleration time is set in seconds (usually not less than 20s) |
| F07.03 | Start protection | 0000 – it is recommended to set all zeros to disable startup blocking when power is applied (i.e., so that the pump can start if the pressure switch was triggered before voltage appeared) |
| F07.06 | Auto-restart after power failure/restoration | 0. Disabled 1. Speed search auto-pickup (recommended) 2. Standard start |
| F07.07 | Auto-restart time after power restoration | Auto-restart time after voltage appears is set (recommended 1 second or more) |
| F07.10 | Stop mode | 0. Smooth stop (according to parameter F01.22) 1. Coast-to-stop (recommended) parameter F01.22 does not apply. The compressor will stop by inertia, i.e., as when operating from a starter |
Let's dwell a bit on connecting the VFD to the automation of a pumping station or pump. Pumps are usually started via a pressure switch. When the water pressure drops below a set level, the pressure switch closes its contacts, and thus power is supplied to the motor. After the pressure reaches the required value, the relay opens and disconnects the voltage supply to the motor. Therefore, when connecting a VFD to this system, there will be no particular difficulties. To do this, disconnect the power wires coming to the pressure switch (power supply) and connect them to the VFD's power input terminals (terminals R S T). The power wires that are on the pressure switch terminals are removed and connected to the VFD's output terminals (to terminals U V W). The free potential-free terminals of the pressure switch are connected to the VFD's start terminals. That is, when the pressure switch trips (when the pump needs to be turned on), the terminals close and send a start signal, and when they open, they send a stop signal.
VEICHI VFD start terminals:
COM and X1 – for AC01, AC310, and AC10 series with power 7.5 kW and higher;
GND and X1 – for AC10 series up to and including 5.5 kW.
Thus, the VFD becomes a starter, controlled by the terminals mentioned above.
If you have any difficulties or questions regarding this integration, please contact the Chastotnik.ua team. We will explain. We will select. We will help.
