Requirements on operation

  • Operation is only permitted within the limits specified on the data sheets. This principle applies to the external safety controller as well as to the drive unit.
  • The built-in diagnostic function is limited in the case of a permanently enabled or permanently disabled STO input. Advanced diagnostic functions are performed only upon a level change of the STO signal. This is why the safety subfunction via the STO input must be triggered with connected supply voltage at least once every 12 months for PL d according to EN ISO 13849‑1 and SIL 2 according to EN 61800‑5‑2 to achieve a complete test coverage. Adhere to the following test procedure for this.

[1]

Maximum 12 months for PL d/SIL 2

[2]

Internal diagnostics

[3]

High: No STO

[4]

Low: STO active

  • To achieve complete test coverage after a device reset (e.g. after connecting the supply voltage), the test transition (STO active → not active) can be started only > 700 ms later. The device signals the "ready for operation" or "STO – Safe Torque Off" state if it is not in fault state.
  • A detected hardware fault in the internal switch-off channels for STO will lead to a locking fault state of the drive unit. If the fault is reset (e.g. by switching the supply voltage on/off or by a low level at the STO input for at least 30 ms), a complete test with internal diagnostics according to the above-mentioned test procedure must be performed. If the fault occurs again, replace the device or contact SEW‑EURODRIVE Service.