Which of the following is NOT typically considered when selecting conductor size for a given load?

• A. Load current
• B. Voltage drop limits
• C. Ambient temperature
• D. Color of insulation

Answer: (D)

When sizing a conductor, you base the choice on how much current it must carry, how much voltage drop is acceptable along the run, and how ambient temperature affects the conductor’s rating. The load current sets the minimum ampacity you need. If the run is long or the voltage drop limit is tight, you may need a larger size. Higher ambient temperatures reduce the conductor’s usable ampacity, so you apply temperature corrections. The color of the insulation doesn’t influence current-carrying capacity, voltage drop, or temperature tolerance; it’s just for identification and insulation type. Therefore, color of insulation is not typically considered when selecting conductor size.