If you tag out a system improperly, what could happen?

• A. Power failure
• B. No effect
• C. System lockout
• D. Accidental discharge

Answer: (D)

Tag-out procedures are about isolating energy sources so equipment can’t move or release energy during maintenance. If a system is tagged out improperly, that isolation isn’t guaranteed—someone could energize or bypass it, or the tag could be ignored or removed by mistake. When energy isn’t reliably held back, it can be released unexpectedly, leading to an accidental discharge. That’s the real danger the question is testing: improper tagging opens the door to unintended energy release that can discharge whatever energy the system contains, posing a serious hazard.

Other possibilities either rely on proper shutdown being achieved, or assume no effect, or require a true lockout in addition to tagging. They don’t directly capture the risk that a faulty tagout introduces a sudden discharge of energy.