Working around electricity in an industrial environment can be very safe if workers are trained to identify and control electrical hazards. The NFPA 70E: Standard for Electrical Safety in the Workplace identifies safe work practices to protect workers from the hazards of electricity, including electric shock and electrocution, arc flash and arc blast, but fatalities from contact with hazardous electrical energy have remained flat for the past decade.

In a May 27 webcast, H. Landis “Lanny” Floyd discussed key steps you can incorporate into your electrical safety program to improve the effectiveness of the requirements in OSHA and NFPA 70E.

Floyd answered additional questions from the webcast on topics such as power supply systems, arc flash, field work audits and more from webcast participants.

Q: Which safety codes are applicable for 12 or 24 Vdc solar photovoltaic power supply systems?

A: The National Electrical Code articles 411 and 720 provides installation requirements.

Q: Please address the effectiveness of protective devices and the proper selection and installation of protective devices.

A: Circuit protective devices serve to limit damage to equipment during fault conditions. These devices are also essential to limiting personnel exposure to the thermal and blast energy during arcing faults.

Q: Please address arc flash and safety environments for testing electrical panels.

A: All of the safe work practice and PPE requirements in NFPA 70E would apply to testing electrical panels.

Q: What should a “field work audit” checklist/form look like?

A: You want to compare work as done to work as imagined. Work as imagined is the procedural steps and safe work practices documented in procedures and policies.

Q: What special considerations need to be accounted for with medium voltage use indoors?

A: All of the safe work practice and PPE requirements in NFPA 70E would apply to MV equipment indoors.

Q: On door-mounted voltage detector, how can you guarantee with your life the wire has not come off the detectors, if it shows no voltage?

A: The same procedure to verify a handheld instrument is functioning can be used. If there is any question, all circuits and conductors should be tested before touching.

Q: Will the IEEE 1584 include the Single Phase to Ground faults for arc flash analysis and verification of associated equations & calculations of such Incident energy?

A: Yes, it will.

Q: Is the NEC or OSHA requiring Electrical Safety training for non-electrical staff working around electrical equipment at commercial and industrial locations?

A: The NEC only has installation requirements. There are no requirements for training in the NEC. NFPA 70E supports the OSHA training requirements for workers who may be exposed to hazardous energy.

Q: Should arc flash analysis and labeling be performed and applied to Disconnect Switches and if so at what voltage and amperage levels do you recommend?

A: You should direct this question to a credible provider of arc flash analysis services. Most disconnect switches above 240 V would likely require labeling, but it depends on a number of variables.

Q: Funding may drive policies with regards maintenance that are not 100% in compliance with the industry standards (e.g., run to failure vs periodic maintenance). From an electrical safety program perspective, what would be the approach to ensure workers are safe and risk is controlled on this situation?

A: If the maintenance policy is to run to failure, then you should assume the equipotent could fail during routine operations. Extra precautions that exceed the recommendations for safe work practices and PPE in NFPA 70E should be used. The safe work practices in NFPAS70E assume the equipment is being maintained.

Q: Do built-in energy testers have enough pedigree to have workers solely relied on that engineering control?

A: Panel mounted voltage indicators are highly engineered and can help reduce risk of exposure to energized circuits before doors or covers on enclosures are opened. They may not eliminate the need to test conductive parts before touching with bare hands.

Q: Of all of the opportunities out there for training, seminars and workshops on electrical safety, what would you recommend as a source of information, technology and leading-edge methods for protection from the hazards?

A: I would look for a training source that devotes a significant part of the curriculum on understanding the hazards of shock and arc flash, as opposed to a review of the rules and regulations for safe work practices and PPE.

Q: Is the improvement made to equipment and facilities given us a false safety feeling?

A: The low frequency of electrical injuries can lead to an illusion of control. There is always residual risk that possibly could be reduced if recognized and addressed

Q: Regarding arc flash analysis, operations and maintenance of a dc system, are there any special considerations or requirements for establishing protection zones and PPE?

A: Yes, the 2018 edition of IEEE 1584 expanded analysis guidelines for dc power systems.

Q: How do recent NFPA 70E changes affect electrical safety programs?

A: Most of the changes in the 23021 edition are editorial in nature. Asa with most revisions of NFPA 70E, the most important requirements are those that did not change.

Q: What is the most common lower order control system employed by professionals that leads to the greatest false sense of security from electrical harm?

A: The lower order controls of Warnings, Administrative Controls , and PPE all are highly vulnerable to human error. Not recognizing this vulnerability is the most common failure that I see.

Q: What are the Europeans actually doing that results in lower electrical accident rates?

A: It is likely not just one thing. However, in 1988, the European Union established requirements for risk assessment that impacted design of tools, components, equipment and facilities a result, the concept of Prevention through Design is firmly entrenched in European safety culture. The US NIOSH Prevention through Design National Initiative launched in 2007 was based on the need to promote the concept in the US.

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