All conductors for systems operating at voltage greater than 300VAC must be designated as what?

Conductors for systems operating at voltages greater than 300VAC must be designated as "identified." This designation is crucial because it signifies that the conductors have specific characteristics or design features that distinguish them from standard conductors. Identified conductors are typically marked or labeled to indicate their intended use and to ensure that anyone working with or around them understands their voltage rating and the associated risks. This helps enhance safety and compliance with relevant standards, reducing the likelihood of accidents or misuse.

In contrast, the other options do not correctly reflect the standard labeling or categorization required for high-voltage conductors. For instance, "high power" could be a qualitative descriptor but does not adequately convey the necessary safety designations. "Critical load" refers to electrical loads essential for the operation of a facility but does not relate to conductor designation. "Low risk" implies a categorization based on safety assessment rather than a specific standard. Thus, "identified" is the correct term that aligns accurately with the requirements for conductors operating above the specified voltage threshold.