In a recent white paper, Schneider Electric explores how improved safety means improved productivity. Specifically, embedded safety drives and Ethernet-networked drives lower hardware costs, increase operator safety, reduce downtime, and therefore improve overall production line performance.

Reducing downtime

Today’s advanced safety technology is not just a means to ensure operator safety but is a way to improve performance. Traditionally, the functions of automated machine safety and control were kept separate, but technological advances now enable safety functionality to be embedded within automation components such as VSDs. The white paper explains how a simplified, integrated approach cuts installation costs, enhances operator safety, and reduces the amount of ‘full shutdown’ downtime, thereby improving overall production line performance.

Operator safety

Ensuring operator safety is a machine process company’s top priority and paramount concern. Consequently, safety always trumps production — a simple safety stop can shut down production for as long as it takes to identify the problem and restart the systems. Given today’s high-throughput production lines, even a relatively short period of downtime can be costly.

Traditionally, the functions of automated machine safety and control were kept separate. Conventional wisdom held that the two systems should be physically and functionally isolated from each other, so that safety would not be compromised by the same faulty condition that led to the control system’s producing a ‘dangerous’ situation in the first place. Or, conversely, some feared that integrating the safety automation and control automation systems would adversely affect the machinery. Operators were protected from hazardous situations by non–automation control electromechanical hardware such as contactors, safety relays, and interlock circuits. The extra expense of OEMs’ building and customers’ maintaining two discrete systems was seen as an unavoidable cost of doing business.

Embedded safety drives

However, technological advances now enable safety functionality to be embedded within automation components such as variable speed drives and servo drives. Instead of compromising the health of machinery, utilising a single drive component can actually improve machine performance and extend its useful lifetime. Advanced safety functions enable safe stop ramps without completely shutting down power to the machines.

This reduces the chances of breakdown since there are no wearing parts, and avoids degradation of machinery due to full-stop-and-restart cycles. Safe speed monitoring ramps allow the machine to slow down sufficiently for an operator to safely perform some types of intervention (clearing a blockage, for example) before the machine is damaged.

Further, networking the safety devices as a cohesive system delivers all the operational and cost-saving advantages of a less-complex system — reduced cabling needs, simplified installation, etc. As noted, a simpler system is generally a safer system.

Benefits of integration

Integrating safety and control systems allows them to ‘talk’ with each other and share data such as diagnostics, system status, alarms, events, and other critical information.  This data sharing improves productivity by enabling faster restart times through minimising the time it takes to identify and troubleshoot a problem — without compromising operator safety.

Download a copy of the white paper How Embedded Safety Drives and Networked Safety Cut Costs and Boost Productivity from 999 Automation