In a significant upgrade to its FR-F700-EC series inverter drives, Mitsubishi Electric has given the range a number of new functions specifically for water pumping application. These include a pre-charge function, built-in PLC functionality, expandable I/O and a unit calculator for PID control.

Pre-charge function

The new pre-charge function eliminates the pressure surges that cause water hammer.  By gradually filling the pipeline, it reduces both the noise and vibration that can compromise system life and ultimately lead to break down of pipeline systems.  Setting options allow the pre-charge cycle to be controlled by feedback level, terminal input or set time.

Built-in PLC

The built-in PLC functionality allows the drives to be used in standalone pumping and water applications and eliminates the need for a separate PLC for sequence control. The built-in PLC has a program capacity of 4,000 steps.

Two option ports allow for both digital and analogue I/O expansion in addition to relay outputs. The I/O can be used to provide feedback to the PLC, and control outputs to valves and other components. For enhanced security in the field, the program can be password protected.

PID

The built-in PLC function enables six different PID set points to be stored, and then selected by a switch on the cabinet door, providing a simple solution in an application that might once have required substantial inverter and PLC programming.

The new control keypad supports PID display values in engineering units allowing for easier set up and monitoring. This is especially useful in pump and fan installations. There are actually 32 different unit settings available, for example, Pascal (Pa), litres per minute (L/min), cubic meters per minute (m³/min) or bar.

With these new functions Mitsubishi Electric has already addressed a number of applications within the pumping and water industry, for example an irrigation system where there were several pipelines of different heights and lengths, but only a single pump and pressure sensor.

Go here for Mitsubishi’s new water productivity brochure

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