Although the National Electric Code does not specify specific conductor colors for three-phase current, it is common to use black, red and blue wires to identify lines L1, L2 and L3 respectively. The voltage cycle of each line lags its predecessor by 120 degrees -- L2 reaches its peak voltage after L1, and L3 reaches its peak voltage after L2.
ELECTRICAL CODE HAZARDOUS LOCATIONS NONHAZARDOUS LOCATIONS (indicate color by letter) N.O. N.C. w/ Blowout N.O. N.C. w/o Blowout Contact action retarded after coil is: Standard Elementary Diagram Symbols. 2 INDUCTORS TRANSFORMERS OVERLOAD RELAYS AC MOTORS DC MOTORS WIRING CAPACITORS
Three-phase electric power is a common method of alternating current electric power generation, transmission, and distribution. It is a type of polyphase system and is the most common method used by electrical grids worldwide to transfer power. It is also used to power large motors and other heavy loads.
For the most part, DC wiring follows the color codes established for AC wiring. The United States uses its own color codes for AC and DC wiring. For DC wiring, the protective ground wire is green or greenish-yellow, negative wires are black, positive wires are red, and white wires are used as the mid-wires in a three-wire grounded circuit.
terminal markings and internal wiring diagrams single phase and POLYPHASE MOTORS MEETING NEMA STANDARDS See Fig. 2-11 in which vector 1 is 120 degrees in advance of vector 2 and the phase sequence is 1, 2, 3.
Electrical contractors and electricians work with electrical wire color codes on a daily basis. But if you're not one of these professionals, you might be wondering what the different colors of electrical wiring signify.