Product news: September 2009

Soft-starts are `world’s most advanced` – perhaps

 Control Techniques has announced two new families of soft-starts, including models with an “adaptive control” function that allows users to select the ideal stop/start profile for an application. The soft-start then analyses each stop and start and adjusts the motor’s acceleration and deceleration to maintain optimum control. This feature is expected to be of particular benefit in applications such as pumping, where it will help to eliminate annoying and potentially damaging water hammer effects.

The adaptive control function is standard on the Digstart IS family of soft-starts which Control Techniques describes as “perhaps the world’s most advanced soft-starter”. This family, which can be used with induction motors up to 800kW, also offers other starting methods including constant current and current ramp, and incorporates multi-language user interfaces with start-up “wizards” to help with commissioning.

The IS models (shown above) also provide real-time performance monitoring and event logging. Parameters can be viewed in real engineering units and shown graphically or numerically. The IP65-protected user interface can be mounted remotely – on a cabinet door, for example. Models up to 110kW (220A) have internal bypass contactors.


The second new family, the Digistart CS, is aimed at motors up to 110kW and is claimed to be one of the smallest soft-starts on the market. It can be configured in seconds using rotary switches and incorporates motor protection facilities. Built-in bypass contactors eliminate the need for external bypass devices and reduce heat generation and energy losses by bridging out the power devices once the motor reaches full speed. This, in turn, saves panel space and will often allow the use of non-ventilated enclosures, according to CT.


Both families of soft-starts offer the option of Profibus, DEviceNet and Modbus RTU communications.