A primary reason for equipment grounding is to provide an effective ground-fault current path. The impedance of the grounding path is directly related to the amount of time a fault exists before the OCPD operates. When impedance is higher, the fault lasts ___ time.

A primary reason for equipment grounding is to provide an effective ground-fault current path. The impedance of the grounding path is directly related to the amount of time a fault exists before the OCPD operates. When impedance is higher, the fault lasts ___ time.

• A. Longer period of time
• B. The same amount of time
• C. A shorter period of time
• D. It has no effect on fault duration

Answer: (A)

Grounding provides a low-impedance path for fault current to return to the source, so the overcurrent protective device can trip. The amount of fault current governs how fast the device operates; higher impedance in the grounding path reduces the fault current, delaying trip time. So when the impedance is higher, the fault lasts a longer period of time.

Grounding provides a low-impedance path for fault current to return to the source, so the overcurrent protective device can trip. The amount of fault current governs how fast the device operates; higher impedance in the grounding path reduces the fault current, delaying trip time. So when the impedance is higher, the fault lasts a longer period of time.