Electrical equipment in non-dwelling units that is likely to require examination, adjustment, servicing, or maintenance while energized must generally be field marked with a label. Which information must be contained on the label?

• A. I and IV
• B. I and V
• C. II and III
• D. II and V

Answer: (B)

When a piece of electrical equipment might need servicing while it’s energized, the label you place on it must quickly convey two things that directly affect safety. First, the voltage present on the equipment so the worker knows the energy level they’re dealing with. Second, the hazard level and the protective gear required—typically shown as the arc-flash PPE category or equivalent hazard information—so the worker can select the proper protective equipment and procedures.

These two pieces of information give a worker the essential context at a glance: what level of electrical danger is present and what protection is needed to work safely without unnecessary de-energizing. Other details that might be useful for maintenance planning aren’t as critical for immediate safety decisions at the point of service.