Lighting Power Supplies

Thanks for your reply.

We have secondary tappings colred yellow (12 V) black (13) violet (14) Red ( 15V) and blue 24 V.

Is this is NEC code requirement ?

Thanks,

What do you mean secondary wires?

Okey... For example lighting system at 120V Line-to-neutral. In our practice in Gulf Region , the standard is L1(Red); L2(yellow); L3(red); Ln(white), grounding wire(green or green with yellow strips). Hot wires practically starts from circuit breaker(red,yellow or blue) then goes to the switch, Neutral wires is from insulated neutral lugs from the panel board and connects to lamp/s load. Switch return normally we use brown color(i think some other countries used in conformity with their own standard practice). To me, the significance/importance/advantage of lightings that wired in color coding system in addition to the standard practice, its easy for maintenance personnel for maintenance issue. Iive got the consensus from some electrical workman, their technical comments (SOP) are they used color coding wiring system especially either single or three-phase.

I mean....L3 is blue color. Abbs. for 3-lines is RYB , 3-phase,5-wires (Red, Yellow, blue, white, green)