What are DC power standards?

DC Power, or direct current power, is commonly used overseas as a way to bring electricity to different locations. While AC (alternative current) is much more popular in the United States for most things, DC is used in certain situations. DC systems include almost anything powered by a battery, solar panel systems, high voltage direct current systems, and many others. DC power systems are not compatible with AC systems (without an adapter), so it is important to have a good understanding of the various standards that apply in this type of environment. This page will offer a brief introduction to the DC power standards.

What is Direct Current?

As the name implies, DC power is when the electrical charge flows in just one direction (rather than alternative back and forth).  Systems that use DC power can use several different configurations of wires depending on the situation. The following are DC power color codes and standards used in most situations in the United States:

  • 2 Wire Ungrounded – In this configuration there will be two wires, one positive and one negative. The positive will typically be red, and the negative will usually be black.
  • 2 Wire Grounded – This setup is more complicated. It will have a positive of a negative grounded circuit (red), a negative of a negative grounded circuit (white), a positive of a positive grounded circuit (white), and a negative of a positive grounded circuit (black).
  • 3 Wire Grounded – When three wires are present it will typically be a positive wire (red) a negative wire (black) and a mid-wire (also known as a center tap) that is white.

When dealing with higher current levels, the wires will increase in size, or gauge. This allows for a greater amount of electricity to flow through the wires at any time. High voltage direct current systems, for example, can carry massive amounts of electricity, and are often used to power things like city train systems and more.


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