The Altivar 21 range of variable speed drives from Telemecanique provides a straightforward, convenient and cost effective way of achieving substantial energy savings.

Incorporating, as standard, a comprehensive range of functions for use with pumps and fans, and featuring an innovative design that minimises harmonic generation, the new Altivar 21 range of variable speed drives from Telemecanique, a brand of Schneider Electric, provides a straightforward, convenient and cost effective way of achieving substantial energy savings in heating, ventilating and air conditioning applications. By replacing fixed-speed starters for fans and pumps with Altivar 21 drives, users not only save energy, but are also able to eliminate inconvenient and often unreliable mechanical flow and pressure control devices, such as valves, throttles and diverters. In addition, in almost all applications, the cost of the new drive and its installation will qualify under the government's enhanced capital allowance (ECA) scheme for 100% tax relief in the first year.

Altivar 21 drives are available in three-phase versions with ratings from 0.75kW to 75kW, and can be supplied as IP20 units for mounting within control panels, or as IP54 models which require no additional enclosure.

Compared with general-purpose industrial drives, all types use a reduced value of DC-link capacitor, which means that harmonic generation is minimised.

EMC performance is optimised by integral filters, which simplify the installation of the drives and save space by eliminating the need for externally mounted filters.

Standard features offered by Altivar 21 drives include a PID regulator for effective flow and pressure control, automatic catching for spinning loads, adjustable switching frequency for noise and resonance suppression, and adaption of current limiting according to motor speed.

Straightforward integration with building management systems is ensured by the availability of optional communication cards, including types for LonWorks, BACnet, Metasys N2 and Apogee FLN.

Comprehensive protection features are also provided, among which are thermal protection with the option to connect PTC thermistors, overload and underload protection, and a jump frequency function to provide mechanical protection for the driven load.

To complement these features, the drives also offer multiple fault management and configurable alarms.

For simple status monitoring and to facilitate minor adjustments, Altivar 21 drives incorporate a seven-segment display panel with a keypad.

This allows speed reference and other key information to be checked quickly without the need for additional equipment, and also gives direct access to the last five parameters modified.