In today’s world, safety seems to be at the forefront of many peoples’ mind. However, in the last century that was not always the case, particularly in manufacturing.
I was recently involved with an upgrade project where the sole purpose was to add complex, safety protection to an old but powerful line of equipment that previously had none. The equipment was designed and placed into production sometime in the mid to late seventies—a time when the idea of safety was “out of sight, out of mind.”
Back in those days, there wasn’t as much thought put into potential hazards like protection from pinch points—the machine’s potential to grab a finger, hand, clothing, or an arm—and an overall consideration of the machine’s fast motions that, in the event of an emergency, cannot stop quickly enough.
In order to address these problems, the brains of the project included a new safety programmable logic controller (PLC) processor combined with several safety I/O cards. This processor was programmed to monitor an array of safety rated limit switches, light curtains, and emergency push buttons. The limit switches were partnered with electronically, lockable guarding gates designed to keep the operators out of critically dangerous areas until the process came to a safe and complete stop. The light curtains were also designed to bring the process to a safe state if an operator crossed over one or more of the beams in the sensing field.
The production line was separated into several safety sections. Depending on which safety inputs were tripped in each section, the PLC would instantly shut down corresponding safety air valves, hydraulic valves, or motor starter contactors. This setup allowed some pieces of equipment to be safely locked out, while other sections were able to keep producing, but only as long as the safety permissive needed for those sections were met.
While many companies claim that safety is their number one goal, it’s all too common that safety upgrade projects—such as the one above—are put into place too late, and only after damage or personal injury has occurred. Most manufacturing companies know and understand the importance of allocating resources to protect, maintain, and improve their capital assets. But what’s a company’s greatest asset? It isn’t the equipment or physical plant, and it isn’t data. The most valuable part of a company is its people—the human capital. By investing in workplace safety, companies can attract and retain quality employees, operate more efficiently, and enjoy a healthy bottom line.
How is your company making appropriate provisions to protect its most important assets?
Brandon DeFanti is a Project Engineer at Avanceon, a certified member of the Control System Integrators Association (CSIA). For more information about Avanceon, visit its profile on the CSIA Industrial Automation Exchange.