Posted to News on 25th Sep 2012, 14:48
SK 200E inverter series provides certified safety up to SIL3
SK 200E distributed frequency inverters from Nord Drivesystems, though optimised for cost-efficient drives, feature several safety functions which, depending on the switching device, enable safe shutdown procedures in high-risk applications that comply with Category 4 or Performance Level e (PL e) according to EN ISO 13849-1.
Conventional frequency inverters in this performance class prevent motors from restarting by disconnecting the voltage supply or the 24V control supply. By contrast, SK 21xE and SK 23xE models feature a certified safe pulse-blocking device as well as digital inputs for the "Disable Voltag" and "Quick Stop" functions. These enable Stop Category 1 (controlled motor braking in line with SIL1), followed by Safe Torque Off (SIL3-compliant) or Stop Category 0 (SIL3-compliant) according to EN 60204-1 (IEC 60204).
Since the voltage supply is blocked without switching off the control or power electronics, the units remain on standby and are ready to be switched on without re-initialisation after the safety circuit is closed. In addition to high availability, the inverters' safety technology provides more economic benefits: contactor components are not required, and since the safety functions are activated electronically, there is no need for regular maintenance or exchange of electromechanical contacts.
To find out more about SK 200E distributed frequency inverters from Nord Drivesystems, go to www.nord.com.
