Danfoss VLT ISD 410 Operating Instructions Manual

Contents

Danfoss VLT ISD 410 Operating Instructions Manual Manual pdf 29 page image

8.3 Activating/Deactivating the Safe StopFunctionThe safe stop function is activated by removing the 24 VDC voltage from pin 4 (safety) of the servo drive. Thiscauses the internal inverter to be blocked in accordancewith the requirements of Category 3. Safe stop can beused to prevent an unexpected start. This means that the24 V DC voltage must be re-applied to pin 4 of the servodrive to end the safe stop and resume normal operation.After this the drive must be restarted via the CAN bus.NOTEServo drives with part numbers 175G7825 and 175G7826are not suitable for the safe stop function.WARNINGRISK ANALYSIS REQUIREDBefore installing and using the safe stop function, athorough risk analysis of the installation must be carriedout in order to ensure that the safe stop function and thesafety level achieved are sufficient and suitable. A commis-sioning test must be performed after the safe stopfunction is installed. Successful completion of anacceptance test is obligatory for compliance with Category3 PL under EN ISO 13849-1. The test is described in8.5 Acceptance Test.The following technical data applies to the various safetylevels:• Typical response time: 1.14 s• Maximum response time: 2.14 s The responsetime is the elapsed time between removal of the24 V DC voltage and switching off the gate driverof the bridge inverter.Data for EN ISO 13849-1• Performance level "d"• Mean time to dangerous failure (MTTFD): > 62years• Diagnostic coverage (DC): 60%• Category 3• Lifetime 20 yearsData for EN IEC 62061, EN IEC 61508, EN IEC 61800-5-2• SIL 2 suitability, SILCL 2:• Probability of dangerous failure per hour (PFH):4.0625 x 10-8/h• Safe Failure Fraction (SFF) >90%• Hardware fault tolerance (HFT):1 [0] (1002 [1001D] architecture)Abbreviation Reference DescriptionCat. EN ISO13849-1Category 1-4FIT – Failure in Time; failure rate: 1E-9hoursHFT IEC 61508 Hardware Fault Tolerance; HFT = nmeans that n + 1 faults may leadto a loss of the safety functionMTTFd EN ISO13849-1Mean Time to dangerous Failure;Mean time to a dangerous failure:(number of units)/(number ofundetected dangerous faults)during the measuring intervalunder the stated conditionsPFH IEC 61508 Probability of dangerous failuresper hour: This value must be takeninto account when the safetydevice is operated in high demandmode (more than once per year)or in continuous demand mode,with the demand on the safety-related system occurring morethan once per year.PL EN ISO13849-1Performance level; a discrete levelused to specify the capability ofsafety-related parts of a system toperform safety-oriented functionsunder given conditions. Levels: a-eSFF IEC 61508 Safe Failure Fraction [%];proportion of safe failures anddetected dangerous failures of asafety function or a subsystem as apercentage of all possible failuresSIL EN 61800-5-2 Safety Integrity LevelSTO EN61800-5-2 Safe Torque OffTable 8.1 AbbreviationsISD Safety Concept VLT® ISD 410 Servomotor Operating Instructions28 MG75D102 - VLT® is a registered Danfoss trademark88