Siemens` drives reach the 4th generation

Siemens has unveiled a fourth generation of its UK-built Micromaster family of drives. The company has invested around £5m in its Cheshire, UK, plant - the world`s largest drives-making factory outside Japan - to develop the new products which it hopes will help it to become the UK drives market-leader.

The Micromaster range includes three families, designed to appeal to different sectors of the AC drives market. They are :

• the general-purpose Micromaster 420, offering flux current control for stable operation and constant torque applications with three-phase motors from 0.12-11kW;

• the high-performance Micromaster 440 (shown above), a vector-controlled frequency inverter initially covering ratings from 0.12-75kW, but extending to 200kW by the end of this year and to 680kW next year; and

• the Combimaster 411, a combined motor-inverter which Siemens claims can cut energy costs by up to 30%.

These will be joined later this year by a simple, fit-and-forget, contactor-style drive aimed at OEMs.

Common features on the drives include: colour-coded, screwless terminal connections; an innovative cooling system that allows the drives to be mounted side-by-side; comprehensive protection; and EMC filters and chokes that mount behind the drive.

The drives have a modular construction so that users only pay for the functions they need. So, for example, there are different types of plug-in operator panel, and communications modules. Compound resistor-free braking and self-calibrating PID controllers are also available.

The top-of-the-range Micromaster 440 models can provide access via the Web to their operating parameters and diagnostics data. They have a built-in kWh counter to help keep a check on power consumption.

The convection-cooled Combimaster 440 can be mounted directly on almost any motor and has a built-in Profibus-DP interface.

To back up the new drives, Siemens is offering several software products including commissioning tools, selection aids, harmonic analysers and energy-saving calculators.

Prices for the new drives are similar to the previous generation but all of the new models are more powerful than their predecessors. When the basic contactor-style drive is launched, probably in October, its price could be as low as £30-40.