Gingoog Electric Trading (G.E.T.) ™

August 9, 2009

DANFOSS Softstarters

Filed under: GET MCD-500 series — Ralf @ 3:42 AM

Soft starts protect gear, goods, equipment and environment

 After the completion of the FC-300 category last month I was supposed, or at least I was actually planning to continue with other VFD’s like the VLT-2800, the VLT Micro or FC-51 or else also with the so called Aqua Drive, the FC-200 series but due to its actuality I decided to shift this month back to the Softstarter topic because we do expect the release of the new Danfoss MCD-500 model now and it is expected to revolutionize the market and to raise the standard once more in this industry.

Before going into more details let us recall again together what Softstarters are about. We spoke already about this product range in the GET Softstarters category but let us just quickly refresh our minds again:

An AC motor in general switched directly on to the mains power supply will ultimately struggle to reach its nominal speed as quick as possible.

This draws maximum current from the power supply and accelerates the application with its maximum torque and depending on the particular application, this can cause different problems.

Applications like pumps, conveyers, centrifuges and bandsaws must be started slowly to prevent mechanical shocks such as water hammer and strains on bands, couplings and shafts.

Principle of a Phase Angle Control:

A Softstarter is an electronic device that regulates the voltage to the motor and this provides a smooth transition from standstill to full speed operation of the application.

DANFOSS VLT Softstarters all use the principle of phase angle control, a back to back coupled thyristors ramp up of the motor voltage.

In some DANFOSS VLT Softstarters, current transformers measure the actual motor current, providing feedback for starting current control but also for numerous motor and application protection functions.

DANFOSS VLT Softstarters cover a comprehensive range:

Soft starting and soft stopping (equally important) can be controlled in a number of ways depending on the application.

Some applications require non linear voltage ramp up and the voltage ramp is therefore related to the actual current drawn. Conversely, a bandsaw as another classic example requires a quick stop function provided by a DC brake.

Then again, a number of applications require a kick-start torque for an instantaneous period of time, followed by a soft ramp up acceleration.

DANFOSS VLT Softstarters do cover all of these applications and much more!

Find much more information in our MCD-500 folder

and visit also our complete GET Sky Drive Section

We certainly do hope that you enjoyed again the read and that you stay with us for more upcoming technical reading pleasure.

Retrieve our GET Contact Details  or send us your E-mail inquiry through the GET Contact Form.

Ralf Wabersich

Gingoog Electric Trading (G.E.T.)


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