Ideally for someone obsessed with completing electrical work in minimal time, you’d work everything hot. But this assumes that doing so would not incur those pesky time drains such as an arc blast or an electrocution — because good luck rains down constantly.
Ideally for someone with zero tolerance for risk, all equipment would be de-energized before it’s worked on. In this world view, the act of de-energizing doesn’t present any of its own risks and it is possible to take voltage measurements or perform thermography on de-energized equipment.
Obviously, some things must be energized for certain tasks to be performed. Aside from that constraint, de-energization is the choice. And that is true even if the whole lockout/tagout process takes longer than the task to be performed.
Perceived time-savings should never be a consideration when making safety choices. In most cases, it is illusory at best. Getting an energized electrical work permit authorized can take more time than shutting something down.
It’s not a simple decision to make. Some of the considerations:
- Does the work require the equipment to be energized? For example, taking voltage measurements, taking current measurements, testing subsystem operation. If so, it’s an Article 130 job.
- Does the work require the equipment to be de-energized? For example, replacing busbar connections, testing motor rotation, performing insulation resistance testing. If so, it’s an Article 120 job.
- Does operations want the equipment out of service to avoid potential quality problems during the work? It may be a mix of Article 120 and Article 130.
- Is the equipment such that de-energization may cause serious problems? For example, it’s a glass plant or a data center. If so, it’s an Article 130 job.
- Would it be easier to work it hot? That’s not relevant.
About the Author
Mark Lamendola
Mark is an expert in maintenance management, having racked up an impressive track record during his time working in the field. He also has extensive knowledge of, and practical expertise with, the National Electrical Code (NEC). Through his consulting business, he provides articles and training materials on electrical topics, specializing in making difficult subjects easy to understand and focusing on the practical aspects of electrical work.
Prior to starting his own business, Mark served as the Technical Editor on EC&M for six years, worked three years in nuclear maintenance, six years as a contract project engineer/project manager, three years as a systems engineer, and three years in plant maintenance management.
Mark earned an AAS degree from Rock Valley College, a BSEET from Columbia Pacific University, and an MBA from Lake Erie College. He’s also completed several related certifications over the years and even was formerly licensed as a Master Electrician. He is a Senior Member of the IEEE and past Chairman of the Kansas City Chapters of both the IEEE and the IEEE Computer Society. Mark also served as the program director for, a board member of, and webmaster of, the Midwest Chapter of the 7x24 Exchange. He has also held memberships with the following organizations: NETA, NFPA, International Association of Webmasters, and Institute of Certified Professional Managers.