Learning Everything about Romex Wire

Learning Everything about Romex Wire

Nonmetallic sheathed cable (NM cable) also known as romex wire is made up of two or more conductors which are insulated and wrapped with a moisture-resistant, flame-proof, and nonmetallic material. Most preferred for indoor wiring, especially for in-house wiring, and is used in most homes. This being cheaper is an adding factor. They are covered with a layer of non-metallic sheathing.

In this article, we will be seeing about Romex wires, its characteristics in detail and the best place to buy Romex wires.

Characteristics Of Romex Wire

Every wire has its own characteristics. Here we will see the characteristics of Romex wires in detail.

Indoor purposes

The specialty of Romex wires is that it specializes in indoor purposes. These also conduct electricity to switches, and other appliances making it an ideal wire for indoor purposes. It’s mostly used in interior residential wiring.

Bare copper grounding

Romex cables use bare copper grounding. With the help of the bare copper grounding, not only does the “leakage current” capacity get maximized but also the sphere-of-influence of the grounding system gets maximized. “Leakage current” refers to the process where when a conductive metal that comes in contact with the earth /soil a certain amount of current exits the grounding system and as a result enters the earth.

Annealed soft copper conductors

The ductility of a cable can be restored and by the process of restoration by heat-treating the copper given that it is heated at the correct temperatures we can also restore not only the flexible nature of the cable but also make the cable soft. Thus annealing is the process of heat treating the cables. And as a result, we get a metal soft annealed copper which is used in Romex wires. Depending on the application it requires a copper wire is used with different degrees of annealing.

Offers wide variety of sizes

Romex wires come in various sizes. These diverse sizes range from fourteen to two AWG (American Wire Gauge). It is two or three conductors. the inner wires which are fourteen gauge have a white sheathing while the twelve-gauge have yellow sheathing.

Designed for home and small business use

Romex NM-B (Nonmetallic sheathed cable) is primarily used for branch wiring in homes. Romex wires are the ideal choice concerning running power from electrical panels and also lights and appliances in your home. its PVC covering supports a variety of purposes including usage in interior walls and garages.

Color coding makes identification easy

Romex wire is color-coded. The color denotes the size of the cable. White Romex which is fourteen gauges are used for basic outlets, commonly used lights, and smoke detectors in one’s household. It has a load capacity of 15 amps which is one of the lowest amperages to exist. The 20 amps yellow Romex which is heavier than the fourteen gauges compared to the White Romex is suitable for microwave or welder.


Alibaba’s Romex wires are highly recommended because it caters according to the insulation material (PVC, rubber, silicone, enameled, and more), application (construction, home, heating, overhead, computer, industrial, and underground), conductor type(stranded and soil) and conductor material (copper core, aluminum, pure copper, and bare copper).