A manufacturer needed to improve the safety of its production systems without completely powering down machines during maintenance or servicing. Traditional safety methods like hard guarding require shutting down and locking out machines, disrupting operations and increasing downtime. The company sought a solution that could isolate hazardous energy and prevent dangerous motion while keeping machines running efficiently.
The Challenge
Ensuring worker safety in environments where hazardous energy and motion exist posed a significant challenge. Hard guarding, while effective at isolating energy, makes servicing machines difficult and time-consuming. Powering down machines to remove guards can cause significant delays, impacting productivity. The team needed to assess risks based on the severity of potential hazards, including the amount of damage a hazard could cause, its frequency, and the speed at which the hazards occur. The solution had to allow machines to be safely maintained without complete shutdowns while adhering to the highest safety standards and regulations.
The Solution
The team implemented a functional safety system that utilized monitored safety devices to isolate energy and prevent dangerous motion without shutting down machines. This solution involved programmable logic solvers to determine when machines should safely shut down. The solvers were integrated using fieldbus technologies approved for safety systems, with distributed I/O enabling efficient management of safety processes. The manufacturer uses ionizing radiation to sterilize medical products and decontaminate foods, which presented multiple hazards such as radiation, high ozone levels, and complex mechanical systems that move product. To address these risks, the team implemented multiple E-Stops (including pull cords), safety mats, light curtains, and door monitoring hardware. They also installed a trapped key search and secure system to prevent unauthorized entry and ensure workers were clear of hazard areas before restarting the process. Additionally, the system included monitoring for potential intrusions, with rapid shutdown capabilities to prevent unauthorized access or dangerous conditions.
The Impact
By using fieldbus distributed I/O with safety features, the team minimized the number of terminations and reduced cabling needs. This resulted in a 25% reduction in system deployment and validation time, significantly improving overall installation efficiency.
