LinMot C1100 series Installation Manual page 18

DC (Diagnostic Coverage) is high (99%) assuming that the state of the feedback contacts is checked after each
change of the state of the control contacts.
MTTF mainly depends on the number of operations of the safety relays.
d
Example calculation of MTTF
Assuming that the safety function is requested every 20s on a machine running 24h per day and 7 days per
week.
B =
10
B =
10d
n =
op
MTTF =
d
=
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:
d
10'000'000
20'000'000 (according EN ISO 13849-1:2008 table C.1)
(24h/Tag*365.25Tage/Jahr*3600s/h) / 20s = 1'577'880 operations per year
B10d / (0.1 x n ) = 126.75 years
op
(This has to be limited to 100years according the standard for further calculations)
high (100 years)
0185-1062-E_6V12_IG_Drives_C1100
Installation Guide C1100
NTI AG / LinMot