Start and stop safely

Electrical switching & drive systems & components

3rd Quarter 2010 Electrical switching & drive systems & components

According to Rynhard Davids, product manager VSD, the soft start/soft stop unit uses both voltage and torque for three-phase squirrel cage asynchronous motors between four and 400 kW.

“With this unit, users can expect a reduction in operating costs, simplified wiring, protection of the electrical installation and space savings. All this comes in a fully equipped product that is safe, innovative and economical,” he says.

The installation and operation of Altistart 22 is simple as it uses six terminals instead of 12, saving time on wiring. The soft start/soft stop unit is also compact, allowing users to optimise the size of their enclosures. Its low heat dissipation keeps temperature rises to a minimum and because it is a multifunction product it reduces the number of components that have to be managed.

Altistart 22 also allows users to bypass any stresses on their applications and so protects their installations. By minimising jolts and shocks, Altistart 22 reduces mechanical stresses on machines and increases their service life. It also prevents installation failures by detecting and signalling faults such as blocked motor, underload or incorrect earthing of one of the three motor phases. In addition, cards are coated to provide an enhanced resistance to harsh environments.

Davids adds that Altistart 22, with its three controlled phases, incorporates all the protection functions needed to monitor the motor, the electrical installation and the starter itself. Setup and operation are simplified with four LEDs, four navigation keys, a four digit display and SoMove setup software which is common to the Altivar, Lexium and TeSys ranges.

The soft start/soft stop unit also integrates application specific functions that optimise machines. These include:

* A centrifugal pump to reduce 'water hammer' and protect against underloads or reversed phase rotation direction.

* A piton pump for the monitoring of pump priming and direction of rotation.

* A fan to detect under- and overloads.

* A turbine for thermal monitoring of the motor with an electrically isolated PTC probe.

* A cold compressor for the monitoring of starting characteristics and the management of automatic restarting.

* A screw compressor and centrifugal compressor to protect against reversed phase rotation direction.

Further optimisation functions include a conveyor that acts as an overload monitor for short-circuit detection or underload monitor for break detection. There is also a conveyor belt which offers a second set of motor parameters, depending on the load carried.

A lifting screw is included for hard spot detection through overload monitoring or break detection though underload monitoring. An agitator/mixer displays the current density of the material and provides a boost on start-up.

“Additional benefits are that Altistart 22 communicates easily with control systems and a remote terminal allows users to communicate with

Altistart 22 without needing to open the electrical cabinet door. Altistart 22 will also be available in IP65 version,” concludes Davids.

For more information contact Rynhard Davids, Schneider Electric SA, +27 (0)11 254 6400, [email protected], www.schneider-electric.co.za

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Start and stop safely

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