What is the specified length for #3/0 AWG conductors?

• A. 42-52 ft
• B. 53-66 ft
• C. 67-84 ft
• D. 85-105 ft

Answer: (C)

Conductor length is limited by how much voltage drop and resistance the run can tolerate while still delivering power safely to the equipment. In R56, each conductor size has a defined maximum run length that keeps the voltage drop within the acceptable range for the expected load.

For #3/0 AWG, the standard tables specify a maximum run length in the 67 to 84 feet range. This reflects the lower resistance per foot of #3/0 wire, which allows a longer run before the voltage drop becomes excessive. Being within this range ensures the equipment receives adequate voltage without violating the site’s guidelines for voltage drop and protection.

Shorter lengths would be conservative but not align with the typical layouts the standard supports, while longer lengths would push the voltage drop beyond the allowed limit for this conductor size. Hence, 67–84 feet is the correct range.