Frequency
inverters for water, drainage and ventilation
The FR-F700 series is tailor-made for operating situations concerning water and drainage. At the same time they meet the various needs of the ventilation sector. They are also able to control other motor operations, such as blowers, centrifuges, certain types of compressor and scraping machines, to name a few.
All the functions that there applications demand are already built in. The built-in energy optimising functions mean that motor operations run at the lowest possible cost all the time!
Power range:
- 0,75–55kW, 3-phase 380–480V
- 75–630kW, 3-phase 380–500V
Pumps and fans
The operating characteristics for these frequency inverters are specially adapted to suit such applications as pumps and fans. Naturally they can also be used wherever constant torque is required. Selection of torque curves is easily predetermined. In demanding operating conditions they can be specially adapted using a 5-point voltage/frequency curve.
Flexible PID controller
The built-in controller enables control of, among others, flow, pressure and level. The feedback in the process may consist of current or voltage signals. A SLEEP function supervises the need for control and switches off the frequency inverter where the need for it is low. As the need for operation increases, the motor starts up again.
A quick start function provides fast acceleration of the motor up to a predetermined speed, and when this is achieved the motor goes over to PID control. One can easily select manual or automatic operation.
Multi-pump operation makes it possible to manage many motors from one frequency inverter. In a pumping station, the system can for example be installed with four parallel pumps. The frequency inverter can control one motor at a time. If necessary a motor can be connected to mains power while a new one is controlled by the frequency inverter. All the logic is built into the frequency inverter.
Communications and networking
An RS485 interface is built in, with Modbus RTU as standard. Apart from traditional network cards such as Profibus, DeviceNet and CC-Link, the frequency inverter can be equipped with a network card for LONworks. The inputs and outputs of the frequency inverter can be used via a network to control external I/O (Remote I/O).
Beijer Electronics can offer network solutions for Mitsubishi PLCs with associated operator terminal applications. For each project there is a Quick start manual that describes installation, connections and application areas for the different programmed modules.
Energy-saving function
In almost all pumping and fan applications there is often a direct energy saving as soon as a frequency inverter is installed. Mitsubishi Electrics frequency inverters have built-in functions to further reduce energy consumption. OEC (Optimum Excitation Control) continuously optimises the motor magnetisation, which can generate savings of up to 10 %. Energy savings can be shown in currency terms directly on the frequency inverter display, or monitored via a network.
Catching rotating loads
When starting a fan, for example, it is not unusual for it to be rotating in the wrong direction due to air flow in the ventilation ducting. This problem is solved in such a way that the frequency inverter monitors the rotation of the motor when starting, to prevent jerking and provide a controlled start. Regardless of whether the motor is stationary, rotating forwards or backwards, the FR-F700 provides a gentle start in all situations.
