Color coded power cables

[siva]

Hi
I am working with US Navy,Bahrain.Here we have a circuit consists of 4 sets of 185 mm2 cables going from LV switch gear to one of the main panel MP1.We pulled 3 sets with R,Y,B and black as neutral and green as ground.Now our stock of R,Y,B is finished and we got black in excess.Is it possible to pull the remaining set with 4 nos of black wires and one green wire.We are ready to apply the color tape at each end.Is there any NEC violation for using two standards(sets of colored cables and sets of color taped black cables for the same circuit?

Thanks
Siva

 

[rcwilson]

Re: Color coded power cables

Siva ? 185 mm is equivalent to 365 kcmil American Wire Gage wire size. Black insulation is allowed for any circuit larger than #6 AWG (16 mm) as long as colored tape or other approved means are used to identify the neutral and ground (earth) conductors at all locations where the conductors are accessible. There is no NEC requirement to identify the phase conductors similar to the Red, Yellow, Blue phasing used in the Mid-East & Asia. (I?m ignoring the orange color needed for high leg identification on mid-point grounded delta systems).

Common practice in the US is to identify the black phase wires with colored tape, (black ? red- blue, brown-orange-yellow) or with ID tags.

Your first circuit does violate NEC because the neutral wire must be identified by white or gray insulation or markings. Black indicates an ungrounded phase conductor. The ground (earth) wire must be green or green/yellow.

 

[mhulbert]

Re: Color coded power cables

It would be easy to make your 1st installation legal by taping that black netral with white phase tape.