Certifications; Failure Probability Of The Safety Functions - Siemens SIMATIC ET 200SP F-TM Equipment Manual

Safety functions integrated in the drive
5.3 System features
5.3.2

Certifications

The safety functions of the F-TM ServoDrive drive system meet the following requirements:
● Safety Integrity Level (SIL) 2 according to IEC 61508 Part 1-3 and IEC 61800-5-2
● Category 3 according to ISO 13849-1
● Performance Level (PL) d according to ISO 13849-1
In addition, the safety functions of the drive are generally certified by independent institutes.
A list of the components that are currently already certified in each case is available on
request from your Siemens branch.
5.3.3

Failure probability of the safety functions

The probability of failure of safety functions must be specified in the form of a PFH value
(Probability of Failure per Hour) according to DIN EN 61800-5-2 and ISO 13849-1. The PFH
value of a safety function depends on the safety concept of the drive device, its hardware
configuration and the PFH values of the other components used for the safety function. For
the F-TM ServoDrive drive system, PFH values are provided as a function of the hardware
configuration.
Note
PFH values
The PFH value of the integrated safety function STO is 30 FIT (10
life of 10 years.
The underlying assumption for the calculation is an average operating temperature of 40°C,
an average repair time of 8 hours and an average time to recovery of 8 hours. A proof test is
not necessary.
48
/h) and refers to a service
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Equipment Manual, 02/2020, A5E47579503-AA
F-TM ServoDrive