Maintenance - ABB ACS355 series User Manual

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
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
Use only ABB approved spare parts.

Proof test interval
The safety integrity of the function does not require any proof testing within the
specified lifetime of the safety function. Regardless of the mode of operation (high or
low demand as defined in IEC 61508, EN/IEC 62061, IEC 61511 and EN ISO 13849-
1), it is a good practice to check the operation of the safety function at least once a
year. Do the test as described in section
The person responsible for the design of the complete safety function should also
note the Recommendation of Use CNB/M/11.050 published by the European co-
ordination of Notified Bodies for Machinery concerning dual-channel safety-related
systems with electromechanical outputs:
• When the safety integrity requirement for the safety function is SIL 3 or PL e (cat.
3 or 4), the proof test for the function must be performed at least every month.
• When the safety integrity requirement for the safety function is SIL 2 (HFT = 1) or
PL d (cat. 3), the proof test for the function must be performed at least every 12
months.
This is a recommendation and depends on the required (not achieved) SIL/PL. For
example, safety relays, contactor relays, emergency stop buttons, switches etc. are
typically safety devices which contain electromechanical outputs. The STO circuit of
the drive does not contain any electromechanical components.
(page 423).
Acceptance test procedure
Acceptance test procedure
Appendix: Safe torque off (STO) 425
(page 423).
on page 423.