When you are working with electrical wiring, there are some important items you need to know. One is how to measure the gauge. Another is the knowledge of what the color means what when it comes to using the wires.
Wire Gauge
First is how to determine the thickness of the wire. This can be somewhat confusing, but the rule of thumb for remembering is: The higher the gauge number, the smaller the diameter of the wire is. I realize that this is counter intuitive, but if you remember,
bigger gauge #=smaller wire diameter, you will be okay. Now, as always, there are exceptions to this rule, but for our purposes, when working with copper electrical wiring, you will be okay with that rule because the majority of household wiring follows this rule.
If you need to know the diameter of a certain gauge, there are several tables you can look at on the internet.
Wikipedia has a nice table. You can also use a
calculator to determine the diameter of wire.
Color Coding on Electrical Wiring
Color coding for wiring is very important. The only two items that are color mandated in the United States is neutral and ground wire. Neutral wiring is either white or gray.
Note: some call the white silver. In the United States, the standard is green, bare copper, or green and yellow striped for ground. Any other color wiring is for the phases wire (the wire that conducts electricity).
Accessories – Different Terminals and Connectors
There is a wide variety of terminals and connectors on the market today for joining wires. What many people do not know is that when choosing a connector, you must know what sizes of wire the colors will fit. Unfortunately, there is no set standard with coloring. For instance, the table below shows the different colors and what each color means for the
wire connectors we carry at
Nelco Products. This table works for our wing connectors as well but only we only carry yellow, red, and blue. This table however, does not work for the
butt splice connectors. These
sizes are for copper-to-copper wiring only.
AWG Color Coding
| Color |
Wire Combination Range
(Inches) |
Wire Combination Range
(mm) |
| Gray |
300V
No. 22 to 16 AWG
Min. 2 No. 22 Str
Max. 2 No. 16 |
300 V
.64 mm DIA to 1.29 mm DIA
Min. .65 mm2
Max. 2.62 mm2 |
| Blue |
300V
No. 22 to 14 AWG
Min. 2 No. 22 Str
Max. 3 No. 16 |
300V
.64 mm DIA to 1.63 mm DIA
Min. .65 mm2
Max. 3.93 mm2 |
| Orange |
600V*
No. 22 to 14 AWG
Min. 1 No. 18 & 1 No. 20
Max. 4 No. 16 & 1 No. 20 |
600V
.64 mm DIA to 1.63 mm DIA
Min. 1.34 mm2
Max. 5.76 mm2 |
| Yellow |
600V*
No. 18 to 12 AWG
Min. 2 No. 18
Max. 4 No. 14 & 1 No. 18 |
600V
1.02 mm DIA to 2.05 mm DIA
Min. 1.64 mm2
Max. 9.14 mm2 |
| Red |
600V*
No. 18 to 10 AWG
Min. 2 No. 14
Max. 2 No. 10 & 2 No. 12 |
600V
1.02 mm DIA to 2.59 mm DIA
Min. 4.16 mm2
Max. 17.14 mm2 |
*1,000V maximum in fixtures and signs.
Each of our other wiring connectors has different colors meaning different AWG sizes. Our
online catalog is the best place to find what part numbers go with each AWG size.
I hope you enjoyed learning a little bit more about wiring and how sizes are determined. A little side note. The size rule, higher gauge=smaller diameter, also works when you are working with sterling silver or gold wire for jewelry.
As always, happy wiring.
Amy
