ABB ACS580-01 drives, Hardware Manual

Page: 205 / 226

Safe torque off function 205
Maintenance
After the operation of the circuit is validated at start-up, the STO function shall be
maintained by periodic proof testing. In high demand mode of operation, the
maximum proof test interval is 20 years. In low demand mode of operation, the
maximum proof test interval is 2 years. The test procedure is given in section
Acceptance test procedure (page 203 ).
In addition to proof testing, it is a good practice to check the operation of the function
when other maintenance procedures are carried out on the machinery.
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 203 ).
Use only spare parts approved by the manufacturer.
Fault tracing
The indications given during the normal operation of the Safe torque off function are
selected by parameter 31.22 STO indication run/stop.
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 drive firmware manual for the indications generated by the drive, and for
details on directing fault and warning indications to an output on the control board for
external diagnostics.
Any failures of the Safe torque off function must be reported to the manufacturer.