A new safe torque off option within the Allen-Bradley PowerFlex 7000 medium-voltage drive from Rockwell Automation helps industrial manufacturers and equipment builders simplify their functional safety design and meet the demands of international safety standards. Safe torque off technology allows users to reliably remove power from the motor without removing power to the drive, enabling a faster re-start of the system after a safe state is reached.
When a safe torque off command is issued in the drive, from a user or a demand on the functional safety system, the PowerFlex 7000 drive immediately removes rotational power to the motor, ceasing the process. The drive stays powered and reliably monitors this "safe" state, ensuring no unintended operation of the motor is possible.
Rockwell Automation engineers designed the safe torque off option directly into the drive control, greatly simplifying setup and system design for functional safety. It works side by side with the drive's control functions and does not require additional electromechanical components. This helps eliminate wiring needs, and lower users' hardware inventory and installation costs. Safety triggers – such as push buttons or light curtains – wire directly to the drive, removing the need for additional hardware.
Ideal for industrial applications, such as material-handling conveyors and grinding mills, the PowerFlex 7000 drive with safe torque off is TÜV-certified. It is also certified to Safety Integrity Level (SIL) 3 of IEC 6150, and Performance Level e (PLe), Category 3 of ISO 13849-1, the highest levels achievable for drives.
The PowerFlex 7000 drive now also offers the option of enhanced torque control capabilities with Allen-Bradley TorqProve technology. Well-suited for heavy-industry applications – such as hoists, draglines, winches and test stands – the TorqProve technology can deliver 100 percent torque at zero speed. The drive's control delivers the higher drive speed and torque response required for vertical lifting applications.
