The FR-A700 is particularly well suited for demanding applications like cranes and lifting gear, high-bay warehous¬ing systems, extruders, centrifuges and winding machines.
Even without encoders the FR-A700 continuously calculates the optimum magnetic flux for every operating state.
A complex motor model and the specifications of the connected standard asynchronous motor are used to improve torque constancy across an extended speed range. For example, the system can generate torque of up to 200 % from a very low starting frequency of just 0.3 Hz. Known as real sensor less vector control (RSV), this new Mitsubishi Electric technology can even be used to regulate the torque. This now makes it possible to use inverters for many applications that were previously the exclusive domain of DC or closed-loop vector drives.
Ultra-precise speed and torque
When operated with an encoder, the FR-A700 drives impress with ultra-precise speeds across the entire control range (precision ±0.01 %) and extremely exact torque control (±10 % precision and ±5 % repeatability). This outstanding performance makes it possible to switch from simple servos to inexpensive frequency inverter systems
Cost effective positioning
In combination with closed-loop vector control the FR-A700 inverters can also be used for positioning, with the control being realized via pulse train, digital inputs or net¬work.
Auto tuningThe optimum performance achieved in encoder less vector operation depends on precise motor data. This new generation of inverters has an auto tuning function that can obtain all the necessary specifications from the motor in less than a minute, even when the motor is not running. You can store the data records for up to two motors. In addition to this, the online auto tuning function automatically registers and com¬pensates changes in the data during operation - for example, changes caused by temperature fluctuations.
Another tuning system known as easy gain tuning simplifies the optimization of the speed control. This system monitors the motor's speed response and automatically optimizes the control parameters, eliminating the need for time-consuming manual adjustment and calibration.
The FR-A700 has very extensive networking capabilities. It comes with both a USB port and a connection for Modbus-RTU as standard equipment. Support is also avail¬able for Profibus, CC-Link, CANopen and the SSCNET III motion control network.
The service-friendly design keeps mainte¬nance times short. Even replacing the entire inverter is a quick and simple opera¬tion; the terminal block is removable and can be plugged directly into the replace¬ment unit.Self-diagnostics prevent downtime this inverter actively monitors its own functions. For example, a pre-alarm is trig¬gered automatically if the fan performance drops to 40 %. An internal program moni¬tors the ageing of the main circuit capaci¬tors and an operating hour’s counter makes it easy to plan the best time for servicing. System protection and overload functions like phase failure monitoring for both the input and output circuits help to ensure trouble-free operation.
More for Your MoneyThese new inverters have ample reserve capacity. For example, even at high frequencies and the high nominal temperature of 50 C (in the ND and HD overload ranges) you still don’t have to reduce the output of the FRA-700. This is made possible by the use of high-quality power stage modules.
An EMC filter is included as standard equip¬ment for full compliance with the EN 61800-3 standard. The FR-A700 models for the range up to 22 kW have an integrated brake transistor and the models up to 7.5 kW have an internal brake resistor.
Long service life guaranteed
Mitsubishi Electric frequency inverter drives are known for their long service life; however the FR-A700 sets even higher standards in this area. Its key components are designed for a life of over 10 years. Among other things, this is achieved with heat-resistant high-performance capaci¬tors and cooling fans with sealed bearings and special lubricants. The PCBs are also protected against aggressive environ¬ments with one or two layers of varnish.
Comprehensive PLC expertise
The integrated PLC functions of the FR-A700 series enable precise configura¬tion for individual application needs. In addition to this, the inverter can even con¬trol simple applications itself without any support from other controllers. The PLC functions also provide access to the FR-A700's internal data registers and the states of its digital and analog I/Os. All the results of math calculations can be stored in the inverter's own EPROM memory, ensuring that the data is safeguarded against power failures.
The internal PLC can be programmed with Mitsubishi Electric's user-friendly GX Developer programming software package.User-friendly operation Configuration and operation of the fre¬quency inverter is simple. Setup is per¬formed with the FR Configurator program, which can also download, store and docu¬ment application data. Oscilloscope and machine analysis functions help the user to optimize the drive system. Data and set¬tings from the predecessor series can be imported directly and converted for use in the new models.
The FR-DU07 configuration terminal with one-touch Digital Dial and 7-segment LED display provides manual access to all parameters and operating modes and is included as standard equipment. The optional FR-PUO7 control terminal features a numeric keypad, plain text display in up to eight languages and enhanced features for storing up to three sets of data and transferring them to other frequency inverters. Getting started or upgrading to the new generation of frequency inverter drives could hardly be easier.