Hi Guys,
IMO;
The code can not state this rule exclusively and simply because there are exceptions to the rule.
I think I would have a hard time convincing a jury of our peers that the code does not expressly prohibit uninsulated grounded conductors, with only a few exceptions which are clearly referenced in 310.2 Exception. Consider the overwhelming evedence that is plainly stated;
NEC 2002
300.3 Conductors.
(A) Single Conductors. Single conductors specified in Table 310.13 shall only be installed where part of a recognized wiring method of Chapter 3.
310.2 Conductors.(A) Insulated. Conductors shall be insulated.
Exception: Where covered or bare conductors are specifically permitted elsewhere in this Code.
FPN:See 250.184 for insulation of neutral conductors of a solidly grounded high-voltage system.
(B) Conductor Material. Conductors in this article shall be of aluminum, copper-clad aluminum, or copper unless otherwise specified.
ARTICLE 310 Conductors for General Wiring
310.11 Marking.
(A) Required Information. All conductors and cables shall be marked to indicate the following information, using the applicable method described in 310.11(B):
(1) The maximum rated voltage.
(2) The proper type letter or letters for the type of wire or cable as specified elsewhere in this Code.
(3) The manufacturer’s name, trademark, or other distinctive marking by which the organization responsible for the product can be readily identified.
(4) The AWG size or circular mil area.
FPN:See Conductor Properties, Table 8 of Chapter 9 for conductor area expressed in SI units for conductor sizes specified in AWG or circular mil area.
(5) Cable assemblies where the neutral conductor is smaller than the ungrounded conductors shall be so marked.
With these examples above, there is no way one could confuse conduit as being an acceptable grounded conductor!
Thanks,
Dave
