Safe torque off

¿Qué significa 5091 ?

The Safe Torque Off (STO) function is active, meaning both STO signals (IN1 and IN2) are switched off or lost, causing the drive to trip. This is a critical safety function that stops the motor for safety. The drive will not start until both STO signals are restored and all faults are reset.

• Intentional activation of the STO function (e.g., emergency stop button pressed, guard door opened) causing both IN1 and IN2 to drop.
• Loss of 24VDC power supply to the external safety relay or PLC safety module driving the STO inputs.
• Complete breakage or disconnection of both STO input cables (IN1 and IN2) at the drive or safety controller.
• Faulty external safety relay or PLC safety output module failing to provide both STO signals.
• Drive internal STO circuit fault where both channels are incorrectly detected as off.

Haga clic en los pasos para seguir su progreso.

1. 1

   Verify the status of the external safety circuit (e.g., emergency stop buttons, light curtains, guard door switches) to ensure they are all in a safe, closed state.

2. 2

   Measure the 24VDC supply voltage at the safety relay or PLC output module that provides the STO signals to the drive.

3. 3

   Measure voltage across both STO input terminals (e.g., X1-X3 and X2-X3) at the drive; expect 24VDC when STO is disengaged.

4. 4

   Inspect all wiring connections for both STO IN1 and IN2 at the safety controller and the drive's STO terminal block (e.g., X1, X2, X3).

5. 5

   Test the external safety relay or PLC safety module by manually engaging and disengaging its outputs, monitoring the STO signals at the drive.