250.119 Identification of Equipment Grounding Conductors.
Code Change Summary: Two new exceptions were added to 250.119 to explain proper equipment grounding conductor identification methods allowed for traffic signals and specific flexible cords.
Section 250.119 spells out all of the ways an equipment grounding conductor must be identified. Equipment grounding conductors can be bare, covered or insulated. Individually covered or insulated equipment grounding conductors must have a continuous outer finish that is either green, or green with one or more yellow stripes except as permitted elsewhere in section 250.119.
The new exceptions allow for two unique circumstances:
- Flexible cords where the conductor insulation is integral to the cord (such as a zip cord or lamp cord) without an equipment grounding conductor, can be green (see image).
- A green wire can be used as an ungrounded (hot) traffic signal conductor. This is permitted from the traffic controller cabinet to the traffic signal head. If this exception is used, then an additional equipment grounding conductor must be installed. This can be in the form of anything permitted in 250.118, but if a wire type equipment grounding conductor is used, it must be bare or green insulation with at least one yellow stripe. This ensures that the ungrounded (hot) green signal wire is not mistaken for the equipment grounding conductor.
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on the “free access” tab and select the applicable year of NFPA 70 (National Electrical code).
2011 Code Language:
250.119 Identification of Equipment Grounding Conductors.
Unless required elsewhere in this Code, equipment grounding conductors shall be permitted to be bare, covered, or insulated. Individually covered or insulated equipment grounding conductors shall have a continuous outer finish that is either green or green with one or more yellow stripes except as permitted in this section. Conductors with insulation or individual covering that is green, green with one or more yellow stripes, or otherwise identified as permitted by this section shall not be used for ungrounded or grounded circuit conductors.
Exception: Power-limited Class 2 or Class 3 cables, power limited fire alarm cables, or communications cables containing only circuits operating at less than 50 volts where connected to equipment not required to be grounded in accordance with 250.112(I) shall be permitted to use a conductor with green insulation or green with one or more yellow stripes for other than equipment grounding purposes.
2014 Code Language:
250.119 Identification of Equipment Grounding Conductors.
Unless required elsewhere in this Code, equipment grounding conductors shall be permitted to be bare, covered, or insulated. Individually covered or insulated equipment grounding conductors shall have a continuous outer finish that is either green or green with one or more yellow stripes except as permitted in this section. Conductors with insulation or individual covering that is green, green with one or more yellow stripes, or otherwise identified as permitted by this section shall not be used for ungrounded or grounded circuit conductors.
Exception No. 1: Power-limited Class 2 or Class 3 cables, power limited fire alarm cables, or communications cables containing only circuits operating at less than 50 volts where connected to equipment not required to be grounded in accordance with 250.112(I) shall be permitted to use a conductor with green insulation or green with one or more yellow stripes for other than equipment grounding purposes.
Exception No. 2: Flexible cords having an integral insulation and jacket without an equipment grounding conductor shall be permitted to have a continuous outer finish that is green.
Informational Note: An example of a flexible cord with integral-type insulation is Type SPT-2, 2 conductor.
Exception No. 3: Conductors with green insulation shall be permitted to be used as ungrounded signal conductors where installed between the output terminations of traffıc signal control and traffıc signal indicating heads. Signaling circuits installed in accordance with this exception shall include an equipment grounding conductor in accordance with 250.118. Wire-type equipment grounding conductors shall be bare or have insulation or covering that is green with one or more yellow stripes.