By Aaron Hand
Try to talk to a machine operator about plant safety, and many times he will cringe, knowing that safety will just get in the way of his ability to produce enough widgets in time, at the right cost. Operators will too often hop the safety fence—figuratively and literally—sure that they are smarter than the machine.
But as Rockwell Automation has been trying to explain this week at the Automation Fair in Chicago, safety and productivity are no longer mutually exclusive. They go hand in hand, with the safety discussion having much more now to do with increased efficiency and machine uptime.
As Derek Jones, safety business development manager for Rockwell Automation, noted, a machine that is stopped when it shouldn't be stopped is the most dangerous kind of machine. "You'll find that somebody did something completely well-meaning, trying to get production back on track," he said. "But the guy hadn't gone through all the proper steps." Next thing you know, the machine starts up again while somebody's arm is still in the danger zone.
Jones presented at the Safety Automation Forum (SAF) along with Mike Miller, functional safety expert for Rockwell Automation. They explained how integrated safety is not only great for safety, but great for productivity as well. "They absolutely go hand in hand," Jones said.
"In the past, the only way to make a machine safe was to stop it," Miller said later in the week in Rockwell Automation's Safety booth. The problem with that was that stopping production often meant destroying some product in the process. The machine could get out of alignment and then would have to be set up again, not a task that a typical machine operator could necessarily do. The whole process meant a considerable loss in machine uptime and throughput.
With the integrated safety technology available today, though, an operator can easily open a door, stop one process, clear a jam, close the door and be up and running again in no time, Miller said. "That also keeps the operator from doing stupid stuff."
The SAF presentations from Jones and Miller reviewed the basics of functional safety, along with the latest safety standards, such as ISO 13849-1 and IEC 62061, because they find that many users are still getting grounded in the basic needs behind safety and what it means for productivity. "We're trying to show people that safety is not a liability," Miller said. Keeping a machine safe means improving machine uptime, improving sustainability, producing less waste and using less energy, they say.
Much as today's faster cars come infinitely more equipped for safety than the 20-mph automobiles of the 1920s, today's machine technology dictates an even greater need for safety than was required in the past. "We didn't really like to think about the probability of failure before. If we had two channels and enough monitoring going on, then we could feel reasonably good about it," Jones said. Now, however, people are realizing that they need to get some data to understand how to apply safety to their processes. "They're trying to calculate, estimate and determine the possibility that something will go wrong so they can apply something proportional to the risk."
The safety standards provide the basic ground rules that engineers should be following. "If you're a good engineer, you might look at these standards and say, 'I already do this.' You're right," Miller noted. "Unfortunately, we're not all at the same level. So standards are written to establish minimum competency. It's very, very easy to continue to do what you're already doing, which is good engineering."
To help meet the standards, Rockwell Automation has the broadest breadth of safety products in the world, according to Tim Robeck, marketing manager, safety systems, for Rockwell's Control & Visualization Business. He was on the Automation Fair exhibit floor, showing off Rockwell's new safety camera technology—easier to use and set up than typical safety curtains, which are prone to misalignment, he said.
Robeck and Miller also discussed Rockwell Automation's next generation of Guardmaster safety relays. The universal relays can monitor a broad range of safety devices in a variety of applications, with six relays able to replace dozens of specialty relays in a typical manufacturing environment, Robeck said. "They provide reduced wiring time, less panel space, less cost and less training."
Besides its products, Rockwell Automation offers safety expertise and training. Miller, for example, is one of only a handful of TÜV-certified safety experts in the world, and has recently trained about 45 new safety engineers. "A lot of our customers don't have the manpower, and safety is still a challenge," Robeck said. "People with safety systems in place are reluctant to change or optimize their systems," he added, because they are afraid they won't understand the new system.
"It's increasingly more difficult, and they're looking to companies like Rockwell Automation that have in-house capabilities," Miller said, "We teach them how to fish."
Increasingly, organizations are becoming aware of the need for safety in automation. "Sometimes it's driven by tragedy," Miller said, "But often it's just an increased safety awareness."