The global site of the UK's leading magazine for automation, motion engineering and power transmission
18 March, 2019

Product and Supplier Search

Facebook

6.6kV digital soft-start is `UKís first`

02 September, 2009

Softstart UK claims to have designed and built the UK’s first home-grown, digitally-controlled, medium-voltage soft-starter. The first installation, rated at 3.3kV, 110A, is due to be commissioned soon.

The currents drawn by high-power motors usually require them to be installed on medium voltage supplies – typically 3.3 or 6.6kV. However, the starting torque surges of these motors can do a lot of damage and soft-starts can offer protection as well as smooth current and torque control.


Softstart’s MV soft-starters cover supplies up to 6.6kV and 720A, with a 400% overload for 30s, making them suitable for motors up to 6.7MW. The company is planning to extend the range up to 11kV, 700A. A 3.3kV soft-starter costs about a fifth as much as a variable speed drive.

The range also offers soft-stopping, gradually reducing the output voltage until the motor comes to a halt. This avoids abrupt and potentially damaging stops and is a particular advantage in pumping and conveyor applications.

The IP54-protected soft-starts incorporate an industrial PC with an 8.1-inch front-panel touchscreen display, and Ethernet and Modbus communications. Bidirectional motor control is optional, as is power factor correction and slip-ring motor control with rotor resistance shorting. The design also accommodates generator set operation with 45–65Hz auto frequency tracking.

Other options include withdrawable line and bypass contactors, and switchfuse disconnects. The lead time for the soft-starts is six weeks, instead of several months often quoted for high-power soft-starts.




Magazine
  • To view a digital copy of the latest issue of Drives & Controls, click here.

    To visit the digital library of past issues, click here

    To subscribe to the magazine, click here

    To see the latest Products & Services Directory, click here

     

Exhibition

Birmingham 2020The next Drives & Controls Exhibition and Conference will take place in Birmingham, UK, from 21-23 April, 2020. For more information on the event, visit the Show Web site

Poll

"Do you think that robots create or destroy jobs?"

Newsletter
Newsletter

Events

Most Read Articles