ABB ACS880-37LC-0390A-7, Hardware Manual, Page: 233 / 242

Description Reference Term or abbre-
viation
Average frequency of dangerous failures per hour for the diagnostic
function of STO IEC/EN 62061 PFH
diag
Performance level. Levels a…e correspond to SIL EN ISO 13849-1 PL
Periodic test performed to detect failures in a safety-related system
so that, if necessary, a repair can restore the system to an "as new"
condition or as close as practical to this condition IEC 61508, IEC 62061 Proof test
Systematic capability 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. T
1
is a parameter used to define the probabilistic
failure rate (PFH or PFD) for the safety function or subsystem. Per-
forming a proof test at a maximum interval of
T
1
is required to keep
the SIL capability valid. The same interval must be followed to keep
the PL capability (EN ISO 13849) valid.
IEC 61508-6 T
1
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
T
M
values given cannot be regarded as a
guarantee or warranty.
EN ISO 13849-1 T
M
Dangerous failure rate (per hour) of the diagnostics function of STO IEC 61508-6 λ
Diag_d
Safe failure rate (per hour) of the diagnostics function of STO IEC 61508-6 λ
Diag_s
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TÜV certificate
The TÜV certificate is available on the Internet at www.abb.com/drives/documents .
The Safe torque off function 233