Safe torque off

Hva betyr A5A0 ?

The Safe Torque Off (STO) function is active, meaning the safety circuit signal(s) connected to the STO connector have been lost or removed. Depending on parameter 31.22, this can be a warning when STO is intentionally activated, or an indication of an unintended safety circuit issue. The drive will prevent motor rotation for safety.

• One or both STO input signals (e.g., STO_IN1, STO_IN2) are momentarily interrupted or lost from the safety controller (PLC, safety relay).
• Incorrect parameter setting (e.g., P31.22 STO fault reaction) configured to issue a warning instead of a trip for a single channel loss.
• External safety relay contacts opening intermittently due to vibration or faulty wiring.
• Loose wiring connection at the drive's STO terminal block (e.g., X1, X2 terminals).
• Fault in the external safety circuit causing one channel to drop out while the other remains active.

Klikk på steg for å spore fremgangen.

1. 1

   Verify the status of both STO input signals (e.g., STO_IN1, STO_IN2) from the safety controller (PLC or safety relay outputs) using a multimeter.

2. 2

   Inspect and re-torque all wiring connections at the drive's STO terminal block (e.g., terminals X1, X2 for STO inputs).

3. 3

   Check parameter P31.22 (STO fault reaction) to confirm it is set to "Warning" (e.g., value 1) for single channel loss if desired.

4. 4

   Measure voltage across STO input terminals (e.g., X1-common, X2-common) to confirm stable 24VDC signals from the safety circuit.

5. 5

   Review the external safety circuit for intermittent contact behavior or short duration signal drops from the safety relay or PLC.