The term “natural” was deleted and a FPN was added to this section. It reads:
(A) Identifying Grounded (neutral) Conductors 6 AWG or Smaller. Grounded (neutral) conductors 6 AWG and smaller must be identified by a continuous white or natural gray outer finish or by three continuous white stripes on other than green insulation along its entire length. Figure 200–3
Author’s Comment: The use of white reidentification tape, paint, or other methods of markings is not permitted on conductors 6 AWG or smaller.
NOTICE: Text that is strikethrough is intended to represent text that is no longer contained in the 2002 NEC.
(B) Identifying Grounded (neutral) Conductors Larger than 6 AWG. Grounded (neutral) conductors larger than 6 AWG must be identified by a continuous white or natural gray outer finish along its entire length, or it can be identified by distinctive white markings such as tape, paint, or by other effective means at its terminations. Figure 200–4
Author’s Comment: Reidentification can be with white tape but not with gray tape.
(D) Mixing Grounded (neutral) Conductors from Different Systems in the Same Raceway or Enclosure. Where conductors from different systems are installed in the same raceway, cable, or enclosure, one system grounded (neutral) conductor must have an outer covering of white or natural gray. The other system grounded (neutral) conductor must have an outer covering of white with a readily distinguishable different color stripe (not green) running along its entire length. Figure 200–5
FPN: Care should be taken when working on existing systems because the color gray may have been used as an ungrounded (hot) conductor.
Intent: This action will address the concern expressed by many that the term “natural gray” is not defined and there is no recognized color or tint that one can readily associate with that term. The addition of the Fine Print Note is to warn individuals that there may be electrical systems where a gray conductor was used as an ungrounded (hot) conductor.
Author’s Comment: The panel rejected a proposal that would have specifically limited white to be used with systems below 150V to ground and gray to be used above 150V to ground. In addition, the panel rejected a proposal to allow 6 AWG and 8 AWG grounded (neutral) conductors to be re-identified in the field by the use of white or gray marking. It could be difficult to distinguish the difference in color between a white and a gray conductor in the same raceway after it has gotten dirty or if it has aged.Images courtesy of Mike Holt Enterprises