PowerFlex and Kinetix Safety Drives

PowerFlex^® and Kinetix^® Safety Drives

Help improve machine uptime and reduce wear and tear with safety-rated PowerFlex and Kinetix drives

The requirement for a machine to be placed in a safe state often needs to be done with a high level of confidence. Many times this is necessary to perform routine maintenance, correct a mechanical problem, or in some cases it may happen very frequently as part of the normal machine process cycle (e.g. punch press). Finding a way to do this without removing power from the system and performing a lockout / tagout procedure can improve process up-time, and reduce wear and stress on mechanical and electrical components. Also, providing an efficient way to exercise functional safety can reduce the chances of safety system tampering.

Safe Torque-Off

For many drive applications, simple removal of torque is all that is necessary to perform the desired task (e.g. maintenance). This function is referred to as Safe Torque-Off (also known as DriveGuard or GuardMotion), and can be accomplished with the use of a standard drive, along with external safety components (e.g. safety contactors) to place the system in a safe state. Some of the PowerFlex and Kinetix drive products reduce the amount of external safety components by integrating safe torque-off functionality inside the drive. Using the integrated solution simplifies the safety circuit design, and reduces panel space and cost. In either case, whether the function is implemented inside or outside the drive, it can be designed to meet the requirements of relevant safety standards.

Safe Speed Monitor

For applications able to benefit from more advanced safety features, Allen-Bradley offers a Safe Speed Monitor option that uses machine or motor velocity feedback for even greater flexibility in how safety can be deployed. This new offering helps provide safety zone access while there is limited motion. By reducing and monitoring the speed of an application, an operator may safely inspect and perform a process operation or maintenance work without stopping the machine, resulting in reduced downtime and reduced production waste. The Safe Speed Monitor is configurable for following functions:

• Safe Torque-Off
  
• Stop Categories 0, 1 and 2
  
• Safe Stop
  
• Safe Limited Speed
  
• Safe Maximum Speed
  
• Safe Maximum Acceleration
  
• Safe Direction
  
• Zero Speed Monitoring
  
• Door Control and Monitoring
  
• Enabling Switch Input
  

In addition to the safe monitoring of speed dependent functions, the Safe Speed Monitor integrates the functionality of a safety monitoring relay, providing direct inputs for interfacing door locks, light curtains, E-Stop pushbuttons, enabling switches, and key switches. While this can be accomplished with a standard drive and a separate speed monitoring relay (Allen-Bradley MSR57), select PowerFlex and Kinetix drives are capable of integrating this functionality internally, again simplifying the safety system, and reducing panel space and cost.