Parker EME Compax3 device description192-120114 N5 C3I22T11 June 2008 893.11.1.3 Advantages of using the "safe torque off" safety function.Safety category 3 according to EN 954-1 and EN ISO 13849-1:Requirements perfor-mance featureUse of the safe torque off function Conventional soution: Use of external switchingelementsReduced switchingoverheadSimple wiring, certified application examplesGroupling of drive controllers on a mains contactoris possible.Two safety-oriented power contactors in series connec-tion are required.Use in th productionprocessHigh operating cycles,high reliability, low wearExtremely high operating cycles thanks to almostwear-free technology (low-voltage relay and elec-tronic switch). The "safe torque off" status is attai-ned due to the use of wear-free electronic switches(IGBTs).This performance feature cannot be reached withconventional technology.Use in th productionprocessHigh reaction speed, fastrestartDrive controller remains performance- and control-oriented in connectted state.No significant waiting times due to restart.When using power contactors in the supply, a longwaiting time for the energy discharge of the DC linkcircuit is required.When using two power contactors on the motor side,the reaction times may increase, you must howevertake into consideration other disadvantages:a) Securing that switching takes only place in power-less state (Direct current! Constant electric arcs mustbe prevented).b) Increased overhead for EMC conform wiring.Emergency-stop function According to the german version of the standard:Permitted without control of mechanical powerswitching elements 1)Switch-off via mechanical switching elements is requi-red1) According to the preface of the german version of the EN 60204-1/11.98, elec-tronic equipment for emergency-stop devies are also permitted, if they comply withthe safety categories as described in EN954-1.
