Wiring Colors | Electrical Wire Color Coding Standards
In the USA, Color Coding wires are reserved for branch circuits, the connection between the last protective device or circuit and the load (the device being powered), and must comply with the National Electrical Code (NEC). Color coding electrical wires is essential for good safety and making a mistake can be life-threatening. Wiring Colors are different in each region of the world, so make sure it's the American Standard you require. Below we will explore what the combinations are for a number of setups.
USA Color Coding (Single Phase)
The standard single phase voltage is 120V in America, and is considered a low-voltage connection.
| Type |
Hot |
Neutral |
Earth |
| Single Phase |
Black or Red
|
White or Gray
|
Green or Green/Yellow
|
USA Color Coding (Multiphase)
Muliphase wiring is more efficient as its loss is minimum compared to single phase configurations. It can carry a much higher, and more stable, electrical current than Single Phase.
| Type |
Line 1
(L1) |
Line 2
(L2) |
Line 3
(L3) |
Neutral
(N) |
Earth
(PG) |
AC Power
(120/208/240V) |
Black
|
Red
|
Blue
|
White
|
Green or Green/Yellow or Bare Copper
|
AC Power
(277/480V) |
Brown
|
Orange
|
Yellow
|
Gray
|
Green or Green/Yellow or Bare Copper
|
How to Wire an American (NEMA 5-15P) Plug
Wiring a plug is a common electrical task that can be done easily when the proper information has been recognized. These types of plugs will always use a single phase wiring combination. American Electrical Plugs have 2 flat prongs as well as a rounded grounding pin (Sometimes a "U" shape). The grounding pin is clearly identified as the earth, and the remaining two flat prongs can be identified more easily once the plug is disassembled.
Shown in the diagram above, the inner screws are color coded to match the wiring:
-Gold Screw is used for the Hot/Live wire, in this case the Black Wire.
-Silver Screw is to be connected to the Neutral, shown here as White/Gray.
-Lastly, the Ground wire will be connected to the top pin, in this case it has a Green screw, but sometimes it is Blue.
