nec 2017 code book( what three colors are ungrounded conductors not permitted to be?)
Click to Enlarge Flexible cords where the conductor insulation is integral to the cord (such as a nothing cord or lamp cord) without an equipment grounding usher, can be light-green.
Code Change Summary: Ii 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 stop that is either green, or greenish with 1 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 nil cord or lamp string) without an equipment grounding conductor, can be greenish (encounter image).
- A green wire can exist used as an ungrounded (hot) traffic bespeak conductor. This is permitted from the traffic controller cabinet to the traffic betoken caput. If this exception is used, then an boosted equipment grounding conductor must be installed. This can be in the grade of anything permitted in 250.118, just if a wire type equipment grounding usher is used, it must be blank or light-green insulation with at least ane yellow stripe. This ensures that the ungrounded (hot) green signal wire is not mistaken for the equipment grounding conductor.
Beneath 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 blank, covered, or insulated. Individually covered or insulated equipment grounding conductors shall have a continuous outer finish that is either greenish or greenish with one or more yellowish stripes except every bit permitted in this section. Conductors with insulation or individual roofing that is green, greenish with 1 or more yellowish stripes, or otherwise identified equally permitted by this section shall not be used for ungrounded or grounded circuit conductors.
Exception: Power-limited Form ii or Course 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 exist grounded in accordance with 250.112(I) shall be permitted to utilize a conductor with light-green insulation or green with one or more than yellow stripes for other than equipment grounding purposes.
2014 Code Linguistic communication:
250.119 Identification of Equipment Grounding Conductors.
Unless required elsewhere in this Code, equipment grounding conductors shall be permitted to be blank, covered, or insulated. Individually covered or insulated equipment grounding conductors shall have a continuous outer terminate that is either green or light-green with ane or more yellow stripes except as permitted in this section. Conductors with insulation or individual roofing that is green, green with one or more yellowish stripes, or otherwise identified as permitted by this section shall not be used for ungrounded or grounded circuit conductors.
Exception No. 1: Ability-limited Class two 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 utilise a usher with green insulation or light-green with one or more yellow stripes for other than equipment grounding purposes.
Exception No. ii: Flexible cords having an integral insulation and jacket without an equipment grounding conductor shall exist permitted to have a continuous outer terminate that is green.
Informational Notation: An example of a flexible string with integral-type insulation is Blazon SPT-2, 2 conductor.
Exception No. 3: Conductors with light-green insulation shall be permitted to be used as ungrounded point 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 usher in accordance with 250.118. Wire-type equipment grounding conductors shall exist bare or take insulation or covering that is green with one or more yellow stripes.
Source: https://www.electricallicenserenewal.com/Electrical-Continuing-Education-Courses/NEC-Content.php?sectionID=49.0
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