Recent ac drive introductions: Mitsubishi, TB Wood's
Variable-frequency drives (VFDs) regularly enter the marketplace. October 2004 introductions include F700 Series drives in the 1-800 hp (0.75-600 kW) range from Mitsubishi Electric Automation Inc. and two S-Series micro ac drives from TB Wood’s expanded E-trAC product line. These VFDs are further described below and Web links to the manufacturers provided.
Variable-frequency drives (VFDs) regularly enter the marketplace. October 2004 introductions include F700 Series drives in the 1-800 hp (0.75-600 kW) range from Mitsubishi Electric Automation Inc . and two S-Series micro ac drives from TB Wood’s expanded E-trAC product line. These VFDs are further described below and Web links to the manufacturers provided.
Mitsubishi’s F700 variable-frequency drives offer serial communications (RS-485) and keypad operation at the same time without the need for added options.
Mitsubishi Electric ’s F700 drive, available for either 200 V or 400 V input, features a new power module and hardware, NEMA 1 structure for panel-type or stand-alone module installation, and programming ease derived from a jog dial that allows fast access to any of 400 operating parameters. F700 also incorporates an Optimum Excitation Control system that maximizes motor efficiency under all load conditions.
Among other features of F700 drive are:
Windmill start: Permits fast, smooth motor control regardless of spin direction by measuring residual motor slot ripple to determine speed and direction of a coasting motor.
Energy saving signal: Calculates and displays energy savings, either in dollars or kW/h.
Power dip ride-through: Allows the inverter to run during short power supply interruptions, reducing nuisance tripping.
Advanced PID mode: Now includes a 'sleep' mode, as well as a pump scheduling feature, to allow intelligent control of up to four motors at once by one drive.
Programmable timer: Generates a signal dependent on drive operating time that comes in handy for planning scheduled machine maintenance.
'This new drive is suitable for virtually any general-purpose application that involves a motor, whether it’s on the shop floor, air-handling unit or machine room,' says Chris Cusick, marketing manager for Mitsubishi Electric Automation.
TB Wood's SW1 S-Series drive (2-hp model shown) illustrates its capability for wireless data transfer via an infrared optical interface.
On a somewhat smaller scale, TB Wood’s Inc . introduces two new VFDs: Simple Economy (SE1) and Simple Wireless (SW1) S-Series micro ac drives. SE1 and SW1 ac drives focus on basic industrial applications. Reportedly, they’re simple to install, economical to use, and reliable. The two drives share a common set of parameters, the first 13 of which meet 80% of users’ most common needs and make start-up fast and easy, according to TB Woods. Another 26 parameters are available for added drive flexibility and functions.
SE1 is available from fractional to 5 hp, while SW1 ranges from fractional to 20 hp. SE1 and SW1 have models with 115, 230, and 460 V input that deliver improved operating efficiency with 5:1 constant torque, Volts/Hertz control for single or multiple motors. A convenient 'Help Card' comes with each drive to define all parameters and identify default-wiring connections.
SW1 also includes an infrared optical interface to permit wireless data transfer of drive settings by using PDA-trAC software for Pocket PC and Palm OS. This function provides easy upload, download, edit and saving of drive parameters. Software can be downloaded from the TB Wood’s Web site.
'With PDA-trAC software, users can transmit and receive SW1 parameter data accurately and quickly without cables or special adaptors,' says Jim Parimuha, S-Series product manager.
—Frank J. Bartos, executive editor, Control Engineering, firstname.lastname@example.org