Drive Techology \ Drive Automatio \ System Itegratio \ Services Data Sheet Fuctioal Safety Safety Characteristics for Brake BE..(FS) Editio 08/2012 19491212 / EN
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Data Sheet Safety otes kva i P f Hz 1 Fuctioal Safety Characteristics for Brake BE..(FS) 1 Data Sheet INFORMATION 1) We reserve the rights to make techical chages. Please observe the data specified i this publicatio. This documet does ot replace the detailed operatig istructios "DR.71-225, 315 AC Motors". Observe the other applicable documetatio 1) : "DR.71-225, 315 AC Motors" operatig istructios "DR. Series AC Motors" catalog "Safety-Rated Brakes Fuctioal Safety for AC Motors DR.71 225" addedum to the operatig istructios "Safety-Rated Drive System" system maual 1.1 Safety otes INFORMATION Meaig of the value "MTTF d ": MTTF d is a statistical value. It is defied i the stadard EN ISO 13849-1 as "expected value of the mea time to dagerous failure". Statistical value meas that it is a value that has bee determied empirically. The value does ot imply a "guarateed operatig life" or a "failure-free time". For the BE.. (FS) brake, the value MTTF d refers to its capability of performig the mechaical switchig operatio, that is to move the pressure plate. Wear of the brake liig, which is caused by the coversio of kietic eergy durig the brakig process, does ot affect this value. The values differ for every applicatio because the value MTTF d depeds o the mea umber of actuatios per year. INFORMATION Observe the techical data of the brake i the "AC Motors DR.71-225, 315" operatig istructios ad the addedum to the operatig istructios "Safety-Rated Brakes Fuctioal Safety for AC Motors DR.71 225". I the latter documet, observe i particular the maximum permitted work doe. INFORMATION Usage i safety-relevat applicatios: The system/machie maufacturer is resposible for compliace of the system/ machie with applicable safety regulatios. If a brake of the type BE.. (FS) is used to fulfill a safety fuctio, the the brake is to be regarded as compoet (elemet) ad ot as a safety-related subsystem. Usually, the BE.. (FS) brake aloe is ot sufficiet to execute a safety fuctio i compliace with the stadard. Data Sheet Fuctioal Safety Characteristics for Brake BE..(FS) 3
1 kva i P f Hz Data Sheet Safety characteristics 1.2 Safety characteristics Defiitio of the characteristic safety value B 10d : The value B 10d specifies the umber of cycles at which 10% of compoets have failed dagerously (defiitio accordig to stadard EN ISO 13849-1). Failed dagerously meas i this cotext that the brake is ot applied whe required. This meas the brake does ot deliver the ecessary brakig torque. Size B 10d Switchig cycles BE05 20,000,000 BE1 16,000,000 BE2 12,000,000 BE5 10,000,000 BE11 8,000,000 BE20 5,000,000 BE30 3,000,000 BE32 3,000,000 Defiitio of the categories: The categories classify safety-related compoets regardig their resistace to errors ad their respose i the evet of a error based o the reliability ad/or the structural arragemet of the parts. A higher resistace to errors meas a higher potetial to reduce risk. Brake type Category (accordig to EN ISO 13849) Brake BE..(FS) without exteral diagostics Category 1 4 Data Sheet Fuctioal Safety Characteristics for Brake BE..(FS)
Data Sheet Sample calculatios kva i P f Hz 1 1.3 Sample calculatios Below some examples of how to use the value B 10d to calculate the mea time to dagerous failure (MTTF d ). I the examples, the values MTTF d are calculated for size BE11 based o 2 differet switchig frequecies. The equatios used are described i stadard EN ISO 13849-1. The followig sample calculatios are based o two selected applicatios. The calculatio has to be adjusted for other applicatios. Also, other parameters might ifluece the calculatio. If you have ay questios o calculatig the values, please cotact SEW- EURODRIVE. 1.3.1 Example 1 Iput data for the BE11 brake: B 10d = 8,000,000 Cycle time: t cycle = 87 s Operatig days per year: d op = 300 d/a Startig frequecy: 41.4 1/h Operatig time per day: h op = 24 h/d Calculatio: MTTF d B10d = 01. x op op d = op s xhop x 3600 h t cycle Isertig the values: d h s 300 24 3600 a d h op = 87s = 297. 931 1 a MTTFd = 8. 000. 000 a = 268, 52a 0, 1 297. 931 Result: MTTF d = 100 years The result is assiged to "High" accordig to stadard EN ISO 13849-1 as show i the followig table. Desigatio Low Medium High Rage 3 years MTTF d < 10 years 10 years MTTF d < 30 years 30 years MTTF d 100 years Data Sheet Fuctioal Safety Characteristics for Brake BE..(FS) 5
1 kva i P f Hz Data Sheet Sample calculatios 1.3.2 Example 2: Iput data for the BE11 brake: Same values as i example 1 but with reduced cycle time Cycle time: t cycle = 9 s Startig frequecy: 400 1/h Calculatio: Make the calculatio as show i example 1. Result: MTTF d = 27.8 years The result is assiged to "Medium" accordig to stadard EN ISO 13849-1. 6 Data Sheet Fuctioal Safety Characteristics for Brake BE..(FS)
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