Danfoss FC302 VLT Automation drive – an in-depth guide

VLT Automation Drives combine functionality with superb design quality.  However they are also built for safety, with a variety of safety concepts in-built with each model.  The purchaser can therefore feel constantly assured by the large array of advanced safety features within each drive.

As an example, torque may frequently be an issue.  Naturally it is important – when the drive is to be deployed in any winding operation – to fully control the tension of the material being wound.  In the case of the FC 302, the drive can easily manage a broad array of torque reference points.  In so doing, it can maintain the tangential tension quite independent of the roll diameter and line speed.

Equally, the load being wound will always affect the acceleration and deceleration of the drive, and therefore the torque required.  With centre winders, the dimension of the roll will even affect torque.  You will, therefore, always need a drive with high-precision torque control.

In addition, the motors that the FC 302 runs are permanent magnet, which enables it to exploit – in high dynamic applications – the full potential of permanent magnet motors.  Beyond torque control, fast processors also enable the drive to precisely control position and acceleration.  The FC302 will also manage the encoder, automatically.  The encoder’s feedback will be compared against a calculated speed, checking to ensure it is functioning correctly at all times.

The VLT® AutomationDrive FC 302 therefore comes with a range of safety features that ensure quality of service, and peace of mind.  Fitted as standard, for example, is the “safe stop” system. This ensures the drive is ideal for category 3 installations.  This prevents the drive accidentally starting  – of course of fundamental importance for applications where unintended starts can be especially problematic. For this purpose, the FC 302 terminal 37 can be used as “safe coast”.  This feature also serves safety standards as defined by EN 954-1 and SIL 2/IEC 61508, whilst category 0 EN 60204-1 is satisfied by the stop function.

With the FC 302, bulky and expensive external components are not needed, and downtime can therefore be minimised.  This feature also means all wiring can be simplified.  Indeed, the electrical connection is extremely simple – simply one wire.  With the FC 302 the safety signals are transferred through discrete signals wiring in compact machinery; whereas in extended manufacturing plants, safe bus communication is used.

As indicated, the VLT® AutomationDrive is already approved for providing safe stop in category
3 installations, without the need for feedback signals from the drive to the safety relay.  As the drive is approved for safety category 3 applications, the pairing of Pilz safety relay with VLT® AutomationDrive is also ideal in obtaining safe stop category 1.

Although the FC 302 comes with as a 600 V, if the desired use is with particularly heavy industry – such as forestry, mining, water and gas supply or chemistry – the 690 V might be the preferred option.  Versions from 11 kW up to 1.2 MW are planned.