The frequency inverter drives of the new FRA700 series from Mitsubishi Electric are high-end units designed for demanding, modern mechanical and plant engineering applications. These drives feature advanced technologies, including:
* Mitsubishi's real sensorless vector control (RSV).
* Integrated PLC with 32 DI and 17 DO.
* Terminal block acting as remote I/O.
* On-board Modbus ASCII/RTU and RS485.
* Motion control (positioning, speed and torque control).
* 270% motor rated current for 0,5 s and 200% for 60 s.
* Connectivity to all open networks.
* Wide range from 0,4 to 630 kilowatts (400 V a.c. and 600 V a.c.).
The drives enable users to configure an economical system tailored to the needs of their applications - either as standalone island solutions or as part of complex systems and machine designs.
Real sensorless vector control
The frequency inverters function precisely, even without complex speed feedback and a key software component of this modern control technology is Mitsubishi Electric's RSV system. RSV provides high torque across the entire adjustment range, even at low speeds. Other benefits claimed by Mitsubishi include improvements in dynamic speed performance, smooth running characteristics and start-up torque. These enable the frequency inverters to achieve levels of performance and control that were previously only possible with DC or servo drives. An effective torque limiting system protects both the motor and the machine. Suspended loads, like those in cranes and hoists, can be positioned precisely with a motor equipped with a pulse generator (closed loop system).
Sensorless vector control is made possible by precise motor data. An auto-tuning function operates even when the motor is not running. This is able to rapidly identify the necessary characteristics of any standard motor. When the system is running, control parameters are adjusted continuously by an online auto-tuning function, which automatically minimises speed fluctuations caused by rising motor temperatures and ensures high-precision operation at all times.
Integrated PLC
The FRA700 series is fitted with an integrated PLC which provides direct access to all drive parameters and can function as an autonomous controller and monitoring device. Engineers can implement their own application program to customise the drive characteristics, thus keeping valuable know-how inside the company.
Plug-and-play configuration
Interfaces to standard industrial fieldbus systems can be implemented with optional expansion cards. The frequency inverters of the FRA700 system can also be used in networked systems together with motion control systems from Mitsubishi Electric. This is made possible by the new option card for the SSCNET (servo system controller network) fieldbus system. The high-speed motion control network is configured by plug-and-play - no transfer parameters need to be entered manually.
Intelligent diagnostics and service functions
Modern diagnostics and maintenance functions protect the inverters against failures and downtime. An automatic self-diagnostic system actively monitors all components that are subject to wear and displays warnings long before the unit can fail. The operating hours counter makes it possible to plan servicing in advance and the service-friendly design ensures the units are quickly back in operation.
User-friendly operation
Setting up and operating the inverters is simple. Automatic motor data identification and an integratal noise filter ensure that the drive is ready for operation immediately. A one-touch digital dial control provides fast access to all important drive parameters. Current operating data and messages are displayed on the removable control unit.
The frequency inverter can be configured and maintained by a PC connected to a standard USB port. The configuration software includes powerful user support functions like graphical machine analysis.
Long service life
Technical improvements and new components ensure that the compact frequency inverters have an above-average service life. High-quality capacitors, robust cooling fans and PCBs with two layers of varnish all contribute to this.
Available in a wide output range
The frequency inverter model FRA700 is available with output capacities from 0,4 to 630 kilowatts, and for three-phase power supplies from 380 to 480 or 500 V (at 50 or 60 Hz). The inverters can handle high overloads of up to 200% for one minute and up to 270% for 0,5 seconds. Other models available are 575 V (FR-A760) power supplies.
CBI-electric: low voltage, is the sub-Saharan distributor of the Mitsubishi Electric range of automation products. This range includes programmable logic controllers, human machine interfaces, variable speed drives, servo drives and Mitsubishi motor control equipment. A qualified team of sales engineers is able to advise customers and supply back-up support and service. All products carry a 12-month warranty.
For more information contact Sheldon Olivier, CBI-electric, +27 (0)11 928 2000, solivier@cbi-electric.com, www.cbi-electric.com
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