For the smallest EGC between switch and motor using DETD fuses and the smallest conductors, the gauge is which?

For the smallest EGC between switch and motor using DETD fuses and the smallest conductors, the gauge is which?

• A. 8
• B. 10
• C. 14
• D. 6

Answer: (A)

The size of the equipment grounding conductor is determined by the rating of the overcurrent device protecting the circuit, per NEC 250.122. For a motor circuit using DETD time-delay fuses with the smallest conductors, the minimum EGC size that satisfies the table is 8 AWG copper. This ensures the grounding path can carry fault current long enough for the fuse to interrupt. Smaller conductors (like 14 or 10) wouldn’t meet the table, and a larger size (such as 6) would be required only if the overcurrent device were larger than the smallest DETD fuse rating. Therefore, the smallest permissible EGC is 8 AWG.

The size of the equipment grounding conductor is determined by the rating of the overcurrent device protecting the circuit, per NEC 250.122. For a motor circuit using DETD time-delay fuses with the smallest conductors, the minimum EGC size that satisfies the table is 8 AWG copper. This ensures the grounding path can carry fault current long enough for the fuse to interrupt. Smaller conductors (like 14 or 10) wouldn’t meet the table, and a larger size (such as 6) would be required only if the overcurrent device were larger than the smallest DETD fuse rating. Therefore, the smallest permissible EGC is 8 AWG.