Hardware Manual

240 Safe Torque off function
* according to Table E.1 in EN/ISO 13849-1
• This temperature profile is used in the safety value calculations:
• 670 on/off cycles per year with T = 71.66 °C
• 1340 on/off cycles per year with T = 61.66 °C
• 30 on/off cycles per year with T = 10.0 °C
• 32 °C board temperature at 2.0% of time
• 60 °C board temperature at 1.5% of time
• 85 °C board temperature at 2.3% of time.
• The STO is a type A safety component as defined in IEC 61508-2.
• Relevant failure modes:
• The STO trips spuriously (safe failure)
• The STO does not activate when requested
A fault exclusion on the failure mode “short circuit on printed circuit board” has
been made (EN 13849-2, table D.5). The analysis is based on an assumption that
one failure occurs at one time. No accumulated failures have been analyzed.
• STO reaction time (shortest detectable break): 1 ms
• STO response time: 2 ms (typical), 5 ms (maximum)
• Fault detection time: Channels in different states for longer than 200 ms
• Fault reaction time: Fault detection time + 10 ms
• STO fault indication (parameter 31.22) delay: < 500 ms
• STO warning indication (parameter 31.22) delay: < 1000 ms
R7 3 3 e 99.65 2.44E-09
(2.44 FIT)
8.70E-7 3847 > 90 3 1 80 20
R8 3 3 e 95.04 3.84E-09
(3.84 FIT)
1.56E-4 1374 >
90 3 1 80 20
R9 3 3 e 95.04 3.84E-09
(3.84 FIT)
1.56E-4 1374 >
90 3 1 80 20
U
N
= 690 V
R5 3 3 e 91.78 2.89E-09
(2.89 FIT)
7.70E-5 1374 >
90 3 1 80 20
R6…R9 3 3 e 95.04 3.84E-09
(3.84 FIT)
1.56E-4 1374 >
90 3 1 80 20
Frame IEC 61508 and EN/IEC 61800-5-2
SIL/
SILCL
SC PL SFF
(%)
PFH
(T1 = 20 a)
(1/h)
PFD
(T1 = 2 a)
MTTF
d
(a)
DC*
(%)
Cat. HFT CCF
(%)
Life-
time
(a)