In inspection practice, tag-out is used to indicate what state?

• A. A subsystem is de-energized or out of service.
• B. A tool is due for calibration.
• C. A subsystem is scheduled for maintenance.
• D. A subsystem has passed inspection.

Answer: (A)

Tag-out communicates that the equipment has been isolated from its energy source and is not to be operated. This is done during inspection or maintenance to prevent energizing or starting the subsystem while work is in progress. A tag is attached to the energy isolation device, often with information about who applied it, why, and when. The equipment remains de-energized and out of service until the tag is removed by the authorized person. The other options refer to calibration timing, planned maintenance, or a status after inspection, none of which convey the safety isolation state that tag-out indicates.