NM-B electrical wire is a very popular type of cable used throughout homes and buildings to bring power from the electrical box to the lights, outlets and appliances. The 14, 12 and 10 AWG circuit sizes are the most common household electrical cables because of the amount of AMPS they offer. Different manufacturers engineer different types of NM-B cable but all types must still meet a certain standard noted in the NEC or National Electric Code.
NM-B Circuit Sizes
NM-B electrical wire circuit sizes are the smallest 3 sizes which are 14, 12 and 10 AWG. The 14 AWG NM-B cables have a white outer jacket, the 12 AWG cables have a yellow jacket and the 10 AWG cables have an orange jacket to set them apart. These three cables run from the electrical box in your home, through the walls to your lights, outlets and appliance outlets. All you will see is an outlet or a light assembly instead of any wiring. Once you pull off the outlet casing you will see the wiring behind it.
Southwire Brand Romex® NM-B Cable
Romex® is a brand name of NM-B cable that Southwire manufactures. It’s similar to buying the brand name of Kleenex® instead of another brand of tissues. It needs to be manufactured to the same specifications per the NEC code but it can be enhanced. Therefore, buying another brand should suffice but buying a premium brand can sometimes lengthen the life of your electrical cable.
Larger Sizes of NM-B Electrical Wire
Larger sizes of NM-B cable refer to 8 AWG through 2 AWG with two or three possible conductors. The bare copper ground wire is additional and not noted when you see: NM-B 6/3. A 6/3 electrical wire will have 3 insulated conductors that are color coded and an additional ground wire without insulation. These cables are more often used to hook up an indoor hot tub, a large appliance or indoor shop equipment. They aren’t flexible at all and cannot be used outdoors either. Therefore, the entire connection must remain indoors if you plan on using NM-B cable or Romex® cable.
Knowledge is power in nearly every industry. Having the knowledge of a subject will allow you to buy and sell in an educated fashion. For instance, understanding that NM-B cables are priced based on the value of copper as a commodity, will allow a savvy buyer to purchase their copper cables at the correct time rather than just replacing a cable when the time comes up.
Written by: Chris Bell