Troubleshooting Safely: Using PtD Methods to Provide Safe Access to Energized Equipment

Control of Hazardous Energy – Lockout/Tagout has once again appeared on the Occupational Safety and Health Administration’s (OSHA) Top 10 Most Cited Violations in 2018. Although this category covers a wide range of violations, it confirms that personnel continue to pursue access into electrical enclosures without being fully aware of the danger involved. Before performing electrical work, OSHA and the NFPA 70E Standard for Electrical Safety in the Workplace both direct workers to de-energize circuit parts to which an employee may be exposed, but why would a worker attempt to access an electrical enclosure without first ensuring that the enclosure is de-energized?

In an increasingly connected and intelligent plant floor, the need to maintain, monitor, or troubleshoot Programmable Logic Controllers (PLCs), motors or Variable Frequency Drives (VFDs) in an electrical enclosure is exponentially increasing. As more and more of this technology is designed in to equipment today, the personnel required to service this technology expands beyond the standard qualified electrician role and into roles inhabited by machine operators, IT personnel, and others. But whether it’s a qualified or unqualified electrical worker, opening an energized electrical enclosure poses the same serious safety risks.

Even though there is inherent risk in opening an energized electrical enclosure, performing service work without power in the equipment is prohibitive to diagnosing or monitoring the equipment. This poses the question: how does a worker safely operate in a potential electrically unsafe work environment and still perform the duties they are assigned? This conundrum has challenged equipment designers to standardize on a solution that allows for personnel who are not electrically qualified to access networks or systems within an electrical enclosure without risk of exposure to hazardous electrical conditions.


APPLYING PtD AND THE HIERARCHY OF CONTROLS TO THE ISSUE

In order to combat this challenge, more and more designers have employed a methodology called Prevention through Design (PtD) when developing products. According to The National Institute for Occupational Safety and Health (NIOSH): “Prevention through Design encompasses all of the efforts to anticipate and design out hazards to workers in facilities, work methods and operations, processes, equipment, tools, products, new technologies, and the organization of work. The focus of PtD is on workers who execute the designs or have to work with the products of the design . The initiative has been developed to support designing out hazards, the most reliable and effective type of prevention.”

Hiearchy of Controls infographic
Hierarchy of Controls infographic by NIOSH. The most effective control methods are located at the top with the least effective at the bottom.

It is interesting to note that NIOSH states that “designing out hazards” is the most reliable and effective type of prevention. This is a core concept that is also shared in the hierarchy of controls system. As represented in the graphic, Elimination (physically remove the hazard) appears at the top of the pyramid and corresponds with being the most effective method of hazard prevention. Substitution (replace the hazard), Engineering Controls (isolate people from the hazard), Administrative Controls (change the way people work), and PPE (protect the worker with Personal Protective Equipment) follow Elimination in a descending order from most effective to least effective, respectively.

Returning to our challenge to standardize on a solution that allows for personnel to access networks within an electrical enclosure without risk of exposure to hazardous electrical conditions, we can apply the Prevention through Design methodology by employing the hierarchy of controls. Since Elimination is the most effective method to design out hazards, the solution to our challenge would be to completely remove any energy within the electrical enclosure. Unfortunately, in this case, removing all energy from the enclosure is prohibitive to diagnosing or monitoring the equipment within, so Elimination is not a practical or reasonable solution to our challenge.

Working down the hierarchy of controls pyramid, our next option is Substitution, the second most effective hazard control. Substitution involves replacing something that produces a hazard with something that does not produce a hazard. For our challenge, Substitution would seem to suggest that we either replace the energized enclosure with a de-energized enclosure, develop a PLC or VFD that somehow doesn’t require energy to operate, or create a separate panel for the PLC without any hazardous voltage. Again, it is impractical to entertain any of these substitutions as viable solutions to our challenge.

This leads us to the next option: Engineering Controls, the third most effective means of controlling hazards. Engineering Controls do not eliminate hazards, bur rather isolates people from those hazards. Isolation involves creating a physical barrier between personnel and hazards and this option seems to have potential. If there were a way to access the PLCs and VFDs in our electrical enclosure without having to open the door to the enclosure and expose the worker to significant risk, we could achieve the most effective hazard control that is practical to our challenge.

A FRESH APPROACH TO A MODERN NEED

Panduit Data Access Port

Isolating personnel from the risk of opening an energized electrical enclosure to access the intelligence inside has led to the development of the Panduit Data Access Port (DAP). The Panduit DAP is mounted on the outside of an electrical enclosure and provides programming ports as well as electrical outlet access without the need to open the enclosure. This allows personnel safe access to PLCs, VFDs, and other internal components without the risk of exposure to electrical hazards. With the Panduit DAP, a practical and successful solution with the most effective hazard control possible for the application has been attained.

While connected and intelligent plant floors continue to develop at the speed of light, there are additional aspects of new technology that often go overlooked. As OSHA’s Top 10 Most Cited Violations has indicated, electrical safety can be an afterthought, but planning for safety should be an important first step when developing new processes or products. The Panduit Data Access Port is designed from the beginning to provide the most effective safety control while still allowing personnel to complete their tasks. Even as intelligent plant floors develop faster than we realize, creating a culture of safety should always move equally as fast.

For more information on Prevention through Design methodology, read our whitepaper.

For more information on Panduit Data Access Ports, visit www.panduit.com

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