Show Menu
Cheatography

Wiring Color Codes Cheat Sheet (DRAFT) by [deleted]

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Introd­uction

Wiring for AC and DC power distri­bution branch circuits are color coded for identi­fic­ation of individual wires. In some jurisd­ictions all wire colors are specified in legal documents. In other jurisd­ict­ions, only a few conductor colors are so codified. In that case, local custom dictates the “optional” wire colors.

IEC, AC: Most of Europe abides by IEC (Inter­nat­ional Electr­ote­chnical Commis­sion) wiring color codes for AC branch circuits. These are listed in Table below. The older color codes in the table reflect the previous style which did not account for proper phase rotation. The protective ground wire (listed as green-­yellow) is green with yellow stripe.

US AC power circuit wiring color codes

US, AC:The US National Electrical Code only mandates white (or grey) for the neutral power conductor and bare copper, green, or green with yellow stripe for the protective ground. In principle any other colors except these may be used for the power conduc­tors. Black, red, and blue are used for 208 VAC three-­phase; brown, orange and yellow are used for 480 VAC. Conductors larger than #6 AWG are only available in black and are color taped at the ends.

US AC power circuit wiring color table

Func­tion
Label
Color, Common
Alte­rna­tive
Protective ground
PG
bare, green, or green-­yellow
green
Neutral
N
white
grey
Line, single phase
L
black or red (2nd hot)
Line, 3-phase
L1
black
brown
Line, 3-phase
L2
red
orange
Line, 3-phase
L3
blue
yellow
 

US DC Power Circuit color codes

US DC power: The US National Electrical Code (for both AC and DC) mandates that the grounded neutral conductor of a power system be white or grey. The protective ground must be bare, green or green-­yellow striped. Hot (active) wires may be any other colors except these. However, common practice (per local electrical inspec­tors) is for the first hot (live or active) wire to be black and the second hot to be red. Usage of the ungrounded system is discou­raged for safety. However, red (+) and black (-) follows the coloring of the grounded systems in the table.

US recomm­ended DC power circuit wiring colors

Func­tion
Label
Color
Protective ground
PG
bare, green, or green-­yellow
2-wire ungrounded DC Power System
Positive
L+
no recomm­end­ation (red)
Negative
L-
no recomm­end­ation (black)
2-wire grounded DC Power System
Positive (of a negative grounded) circuit
L+
red
Negative (of a negative grounded) circuit
N
white
Positive (of a positive grounded) circuit
N
white
Negative (of a positive grounded) circuit
L-
black
3-wire grounded DC Power System
Positive
L+
red
Mid-wire (center tap)
N
white
Negative
L-
black