ABB ACS880-17 - Competence

208 The Safe torque off function
Include the Safe torque off operation test described above in the routine maintenance
program of the machinery that the drive runs.
If any wiring or component change is needed after start up, or the parameters are restored,
follow the test given in section Acceptance test procedure (page 205).
Use only ABB approved spare parts.
Record all maintenance and proof test activities in the machine logbook.
 Competence
The maintenance and proof test activities of the safety function must be carried out by a
competent person with adequate expertise and knowledge of the safety function as well as
functional safety, as required by IEC 61508-1 clause 6.
Fault tracing
The indications given during the normal operation of the Safe torque off function are
selected by motor-side converter control program parameter 31.22.
The diagnostics of the Safe torque off function cross-compare the status of the two STO
channels. In case the channels are not in the same state, a fault reaction function is
performed and the drive trips on an “STO hardware failure” fault. An attempt to use the
STO in a non-redundant manner, for example activating only one channel, will trigger the
same reaction.
See the firmware manual of the motor-side converter control program for the indications
generated by the drive, and for details on directing fault and warning indications to an
output on the control unit for external diagnostics.
Any failures of the Safe torque off function must be reported to ABB.
Safety data
The safety data for the Safe torque off function is given below.
Note: The safety data is calculated for redundant use, and does not apply if both STO
channels are not used.
Note: The safety data for the STO function is not verified by the certification body. The
verified safety data for the STO can differ from the data given in this manual.
Frame SIL/
SILCL
PL SFF
(%)
PFH
(1/h)
PFD
avg
(T
1
= 2 a)
PFD
avg
(T
1
= 5 a)
MTTF
D
(a)
DC*
(%)
Cat. HFT CCF
(%)
Lifetime
(a)
R11 3 e 99.66 3.65E-09 3.20E-05 8.00E-05 20219 >
90 3 1 80 20
3AXD10000481168