BETTER SAFE THAN SORRY WITH VSDS MACHINERY & MACHINE SAFETY
Globally, there are approximately 340 million occupational accidents each year, according to the united nation’s international labour organisation. With lives at risk, the safety of industrial machinery is a serious business. Here, marek lukaszczyk, european and middle east marketing manager at motor and drive manufacturer, WeG, explains how variable speed drives (VSds) with built-in safety features can be used to protect workers and equipment while reducing the number of safety devices necessary: saving space and cost.
M
otors are at the heart of many plants, powering everything from compressors to centrifuges - often
running continuously and in harsh conditions. With such hard-working equipment, no matter how reliable, it is almost inevitable that, at some point, something will go wrong. Wherever a fault occurs in a production line, it is imperative that any motors can be switched off safely, in a controlled manner, to avoid compounding the damage to equipment, product, or worst-case scenario, people. That is why any industrial machinery should
be connected to safety devices. However, multiply that by all the different pieces of
equipment found within a large factory and you can see how costs easily begin to rise, and cabinet space begins to shrink. VSDs with built-in safety features are a
great solution to this problem. VSDs control motor speed and torque by varying the frequency and voltage of the electrical current being fed into the motor. Prized for their energy and cost-saving potential, VSDs can also play a role in machine safety.
Safer and Streamlined By choosing a VSD with built in safety features, manufacturers can take advantage of a range of benefits. First and foremost, by not using an external electromechanical safety device, safety responses will happen faster - making the system safer - and system restarts by the VSD will be quicker too, minimising any delays to production. Using VSDs with built-in safety features also
means less safety components to install, resulting in an installation that is easier and cheaper, a benefit that extends to maintenance too. It also saves space in cabinets, making machinery more compact. In these VSD models, redundant input
terminals are dedicated to safety features, including external failure monitoring, so none of the functionality of the VSD is lost. Plus, even in the event of other failures in the VSD, the safety procedures will remain active — safety always has the highest priority. Manufacturers looking to install VSDs with built-in safety features in their facilities need to get them certified by an unbiased third party in accordance with international safety standards.
Safety featureS in action WEG has updated its reliable and robust CFW VSDs with the two most popular safety functions, safe torque off (STO) and safe stop one time controlled (SST1-t). The STO function makes it impossible for the
motor shaft to produce any torque, meaning the motor will coast to a stop if it is rotating, and preventing any unexpected start-ups. This feature is essential for times when workers need direct contact with dangerous moving parts, whether during set up, operation or maintenance. It is particularly useful in relation to conveyors, fans, pumps, compressors and hydraulic presses. By contrast, when the SS1-t is triggered,
there will be a pre-defined delay time, during which the VSD will gradually decelerate the motor before the power is cut off. It is needed for applications where inertial loads need to be slowed down before coming to a stop, such as centrifuges, mixers, dissolvers and mills. Both safety functions are available in a
single plug-in module, easily installed with simple wiring and programming. By choosing VSDs with built-in safety
functions, manufacturers can take advantage of a faster response time and reduced footprint, meaning safer and smaller machines. With so many workplace accidents taking place each year, these VSD models mean manufacturers can rest assured they have done the most they can to protect their workers and equipment, without losing profit.
WeG
www.weg.net
40 NOVEMBER 2021 | FACTORY&HANDLINGSOLUTIONS
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58
