Terms And Definitions - WEG CPW17 User Manual

2.4 TERMS AND DEFINITIONS

CPW17
„
Emergency Stop Safety Relay from WEG Company.
PLMP
„
Standard screw fixing adapter from WEG Company.
CAT
„
Category: Classification of the safety-related parts of a control system in respect of their resistance to faults and
their subsequent behavior in the fault condition, and which is achieved by the structural arrangement of the parts,
fault detection and/or by their reliability.
[EN ISO 13849-1:2015]
PL
„
Performance Level: Discrete level used to specify the ability of safety-related parts of control systems to perform
a safety function under foreseeable conditions.
[EN ISO 13849-1:2015]
SIL
„
Safety Integrity Level: Discrete level for specifying the safety integrity requirements of the safety functions, where
safety integrity level 4 has the highest level of safety integrity and safety integrity level 1 has the lowest.
[IEC 61508:2010]
PFD
„
Probability of Dangerous Failure Demand: Safety unavailability of safety-related system to perform the specified
safety function when a demand occurs from the control system.
[IEC 61508:2010]
SFF
„
Safe Failure Fraction: Property of a safety related element that is defined by the ratio of the average failure rates
of safe plus dangerous detected failures and safe plus dangerous failures.
[IEC 61508:2010]
SIL CL
„
SIL Claim Limit: Maximum SIL that can be claimed for a safety related electrical control system in relation to
architectural constraints and systematic safety integrity.
[IEC 62061:2005]
PFHd
„
Probability of dangerous Failure per Hour: Average probability of dangerous failure within 1 h.
[IEC 62061:2005]
General Information
CPW17 | 9