In order to establish an effective ground-fault current path, impedance must be ___.

In order to establish an effective ground-fault current path, impedance must be ___.

• A. multi-phase
• B. low
• C. reciprocal
• D. high

Answer: (B)

Low impedance is needed for an effective ground-fault current path. The fault current that flows during a ground fault is determined by the source voltage divided by the impedance of the path; the lower that impedance, the higher the fault current. A low-impedance path allows enough current to reach protective devices ( breakers, GFCIs, etc.) quickly, so the fault is detected and cleared fast, reducing shock risk and equipment damage. If the path had high impedance, the fault current would be limited and might not trip the protective device promptly, leaving the fault present longer. Factors like the integrity of the grounding conductor, connections, and soil conditions influence this impedance, and the goal is to maintain a path with as little resistance as practical.

Low impedance is needed for an effective ground-fault current path. The fault current that flows during a ground fault is determined by the source voltage divided by the impedance of the path; the lower that impedance, the higher the fault current. A low-impedance path allows enough current to reach protective devices ( breakers, GFCIs, etc.) quickly, so the fault is detected and cleared fast, reducing shock risk and equipment damage. If the path had high impedance, the fault current would be limited and might not trip the protective device promptly, leaving the fault present longer. Factors like the integrity of the grounding conductor, connections, and soil conditions influence this impedance, and the goal is to maintain a path with as little resistance as practical.