This blog overviews the most popular types of building wire used in houses and commercial buildings.
Building wire is the most popular subtype of wire and cable, with the most significant share of the market. This subtype of wire and cable is used in the construction of commercial, residential, and industrial buildings. They are most commonly used as power cables in branch circuits.
Building wire is often referred to as home wiring because building cables are used in homes as power cables. However, the term "home wiring" also encompasses other non-power cables used in homes, such as communication cables (twisted pair, coaxial, fiber optics, USB) and low-voltage 30V appliance cables that are not building wire.
THHN is simply the most popular type of wire and cable used in the construction of all types of buildings. This single-conductor wire is also perhaps the market's most versatile subtype of building wire. It is used as a hook-up wire, machine tool wire, circuit wire, and appliance cable. In private homes, THHN wire is often used in conduit in areas like basements and garages.
THHN is coated with nylon and has high heat resistance. THWN, a variation of THHN, has the added benefit of water resistance. Perhaps, the one possible drawback of this highly versatile cable is that it is not approved for direct burial. Read this blog to learn more about burying THHN in conduit.
XHHW/XHHW-2 is, in many ways, a cable very similar to THHN but with a more expensive thermoset XLPE insulation. This insulation has a better resistance and makes for a more flexible cable. However, this makes XHHW/XHHW-2 a more expensive cable than THHN. Here is a more detailed overview of the differences between THHN and XHHW ratings.
VNTC is a THHN/THWN cable improved by two valuable features: it can be installed in trays and buried directly in the ground. One of our earlier blogs explores VNTC in greater detail.
Service entrance cables are cables used in panel feeders and branch circuits to bring power from the source to buildings. They have XHHW-2- like insulation and are not used for any other purpose inside a house. Click here to read about the differences between SER and SEU. Service entrance cables are used in both private homes and multi-storeyed buildings.
MC cable is used as a power cable in Commercial, industrial, and residential buildings of all types and heights. It can be used as an alternative to building wire in conduit. The cable is commonly used in large appliances.
This is a building wire with RHH RHW-2 rubber insulation that is slightly heavier than other types of insulations used with home wiring. It is used for all types of lighting and power uses in buildings. USE cables are approved for direct burial.
UF-B cables are used for underground wiring outside buildings as underground feeder cables and for lighting. In conduit, they can also be used above the ground. This is one of the more expensive building wires. The difference between USE and UF-B rating is explored here.