What does the Let-Go Current Value refer to?

• A. It refers to the current level that triggers a circuit breaker.
• B. It refers to the current level that prevents an individual from letting go of an energized circuit due to loss of motor control.
• C. It is the maximum safe current for a person to touch.
• D. It is the average current in household circuits.

Answer: (B)

The Let-Go Current Value is the current through the human body that causes a person to lose the voluntary ability to let go of a live energized conductor due to muscle contraction. It’s a safety threshold used to assess shock hazards and guide protective measures, rather than a device setting or a typical electrical current level in circuits. It can vary with factors like contact path (hand to hand vs hand to foot), voltage type (AC vs DC), frequency, moisture, skin condition, and whether gloves or other barriers are used.

This isn’t about when a circuit breaker trips, nor about a maximum safe current to touch or an average household current. It specifically describes the physiological limit at which releasing the energized object becomes difficult or impossible.