User Manual

Overview
3.5 Failure rates
SIRIUS ACT 3SU1 pushbuttons and signaling devices
System Manual, 02/2015, A5E03457306020A/RS-AB/002
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3.5
Failure rates
Using the B10 value, the failure rate of the command and signaling devices is calculated
according to the following formula:
λ = [0.1 x C / B10]
λD = [0.1 x C / B10d]
λ = Total failure rate of a command and signaling device
λD = Failure rate of dangerous failures
C = Operating cycle per hour
B10d = B10 / Proportion of dangerous failures
SN 31920 standard
The B10 value for devices subject to wear is expressed in the number of operating cycles.
This is the number of operating cycles at which during a lifetime test, 10% of the test objects
have failed (or: number of operating cycles after which 10% of the devices have failed).
Note
Refer to the respective data sheet for the B10 value and the proportion of dangerous
failures.