Wiring Colors

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 Hot Wiring Colours Black Hot Wiring Colours
Black or Red
White Neutral Wiring Colours Gray Neutral Wiring Colours
White or Gray
Green Earth Wiring Colours Green/Yellow Earth Wiring Colours
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 L1 Wiring Colours Black Red L2 Wiring Colours Red Blue L3 Wiring Colours Blue White Neutral Wiring Colours White Green Earth Wiring Colours Green/Yellow Earth Wiring Colours Bare Copper Earth Wiring Colours
Green or Green/Yellow or Bare Copper
AC Power
(277/480V)
Brown L1 Wiring Colours Brown Orange L2 Wiring Colours Orange Yellow L3 Wiring Colours Yellow Gray Neutral Wiring Colours Gray Green Earth Wiring Colours Green/Yellow Earth Wiring Colours Bare Copper Earth Wiring Colours
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. 
US Plug Wiring Diagram
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.
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