ABB ACS180, Руководство по оборудованию, Страница: 161 / 168

Description Reference Term or ab-
breviation
Average probability of dangerous failure on demand,
that is, mean unavailability of a safety-related system to
perform the specified safety function when a demand
occurs IEC 61508 PFDavg
Average frequency of dangerous failures per hour, that
is, average frequency of a dangerous failure of a safety
related system to perform the specified safety function
over a given period of time IEC 61508 PFH
Performance level. Levels a…e correspond to SIL EN ISO 13849-1 PL
Periodic test performed to detect failures in a safety-re-
lated system so that, if necessary, a repair can restore
the system to an "as new" condition or as close as prac-
tical to this condition IEC 61508, IEC
62061 Proof test
Systematic capability (1…3) IEC 61508 SC
Safe failure fraction (%) IEC 61508 SFF
Safety integrity level (1…3) IEC 61508 SIL
Safe torque off IEC/EN 61800-5-2 STO
Proof test interval. T1 is a parameter used to define the
probabilistic failure rate (PFH or PFD) for the safety
function or subsystem. Performing a proof test at a
maximum interval of
T1 is required to keep the SIL cap-
ability valid. The same interval must be followed to keep
the PL capability (EN ISO 13849) valid.
IEC 61508-6 T1
See also section Maintenance.
Mission time: the period of time covering the intended
use of the safety function/device. After the mission time
elapses, the safety device must be replaced. Note that
any
TM values given cannot be regarded as a guarantee
or warranty.
EN ISO 13849-1
TM
￭ TÜV certificate
The TÜV certificate is available on the Internet at www.abb.com/drives/documents .
The Safe torque off function 161