While keeping up with safety standard evolution, a safety leader successfully designed an integrated safety system to improve efficiency and productivity
For decades, machine builders approached safety as an “add-on.” They designed the machine first, and then applied guarding and other safety components later.
Still prevalent today, this method helps an OEM to achieve safety compliance, but often at the cost of productivity.
With the matter of cost, the fact that there are significant similarities and distinctions between the functional safety standards, IEC 62061 and ISO 13849, which had caused their merger project – IEC/ISO 17305 – stopped for now, has been a critical issue that OEMs should consider whenever they build machines.
When Two Standards Meet
To tackle down various challenges, global leading OEMs can adopt a comprehensive approach.
One of the successful cases is that, Paper Converting Machine Company (PCMC), a Wisconsin-based global leader in tissue converting, packaging, flexographic printing and non-woven technology, has been able to capitalize the advantages of both standards and used a combination of modern safety standards, latest control and software capabilities to design safety into machinery.
Instead of being slowed down by the complexity brought by multiple standards, PCMC endeavored to make machinery upgrades that improved both efficiency and safety.
Moreover, it took a big step forward to make functional safety an integral part of the design process across its portfolio and in upgrades that support legacy equipment.
PCMC now can use the standards to implement contemporary safety technologies. For example, it uses zone control to divide a complex converting line into safety zones that correspond to specific risks or hazards.
The system can be configured to remove power safely from one zone, so a maintenance technician can service it while keeping the rest of the line up and running.
“Our process begins with a risk assessment, which helps define which hazards are present — and what we can do about it,” explained Jason Stover, senior electrical project engineer, PCMC.
“First and foremost, we design the hazard out of the machine if at all possible. If we can’t design it out, we look at protective measures that can reduce risk.”
In addition, to achieve safety functionality, the PCMC equipment is built on a Rockwell Automation® integrated safety solution based on the Allen-Bradley® GuardLogix® platform.
Their design process includes a risk assessment and defining functional-safety requirements early on, then verifying and validating the safety system when it is completed.
Depending on the application, the machinery also includes Allen-Bradley Kinetix® 6500 servo drives for coordinated drive control and Allen-Bradley PowerFlex® 525, 755 and 70 AC drives for variable-speed control. The Kinetix and PowerFlex drives include built-in safety functionality via the Safe Torque-off feature.
Safe Torque-off capability removes rotational power from the motor without powering down the entire machine. As a result, equipment can be brought to a stop more safely — and restarted more quickly.
The robust safety solution also incorporates POINT Guard I/O™ and other safety-rated components as required.
With Rockwell Automation functional safety specialists supporting PCMC’s in-house expertise, the company can continue to evolve the design philosophy in line with regulatory requirements and advances in technology.
Make Safety an Inherent Value
Besides having all its engineers trained thoroughly on machine safety, PCMC believes that the need for thorough validation and documentation has increased as safety control architectures have become more robust, therefore it provides the customers with safety documentation during equipment installation and the documents are electronically stored to support equipment throughout its life cycle; machine safety training is also offered as part of the aftermarket services.
“We differentiate ourselves from competitors by guiding our customers through the safety process and educating them on the opportunities safety presents,” Stover says.
“Some might not recognize safety as a fundamental part of the equipment, but by the time we’re done, they see the value.”
Despite of the fact that the on-going evolution of safety standards has brought challenges to global OEMs, there are organizations choose to make safety a core business value in their operations.
Rockwell Automation’s Manufacturing Safety Excellence Awards continues to recognize these best-in-class manufacturers; this year’s nominations are open and companies that seek to improve safety while also improving productivity are all welcome.