What size aluminum equipment grounding conductor is required for a circuit protected by a 70-ampere fuse?

The requirement for the size of an aluminum equipment grounding conductor can be determined by looking at the National Electrical Code (NEC) guidelines, specifically Table 250.122, which outlines the proper grounding conductor sizes based on the rating of overcurrent protective devices such as fuses.

For a circuit protected by a 70-ampere fuse, the code specifies that the minimum size for an equipment grounding conductor made of aluminum should indeed be 6 AWG. This size ensures that the grounding system is adequate to safely handle any fault current that may occur, thereby protecting both the electrical system and the individuals utilizing it. Grounding conductors play a crucial role in providing a path for fault current to minimize the risk of electrical shock or fire.

The answer indicating two 8 AWG conductors would not meet the code requirements for a single grounding conductor size and may complicate the system unnecessarily. Similarly, 10 AWG aluminum is too small and does not provide the necessary safety margin for a 70-ampere circuit, while 8 AWG aluminum is also below the standard, failing to comply with the grounding needs outlined in the NEC.

Therefore, selecting a 6 AWG aluminum grounding conductor guarantees compliance with safety regulations and ensures the system operates