Types of Electrical Wire
There are many types of electrical wire, each specific to the condition that the wire will be placed in. Some are for indoor use only, some can be buried directly in the earth and some have added options. Learn about each basic type of electrical wire as well as the most popular types of electrical wire for common applications.
THHN wire is the single copper hook up wire used alone and inside other electrical cables in the industry. THHN stands for Thermoplastic High Heat resistant Nylon jacket the dual rated THHN/THWN wire adds in “Water Resistant”.
Romex® is an indoor-only cable manufactured with THHN wires and a thin PVC jacket made solely for ease of installation. Otherwise, electrical contractors must run each THHN wire by itself or tape them together and attempt to run them as one. Romex® cables were made to be cheaper because when adding all the bells and whistles you’ll end up with a much more expensive cable.
MC cable was manufactured because contractors wanted to run Romex® cable outdoors and in conduit but couldn’t because the jacket was thin and the bare copper ground wire could be damaged. So Southwire decided to change the jacket slightly and also make the ground wire insulated, using a THHN wire instead of bare copper.
MC cable can now be used outdoors and in conduit. There is also a PVC jacketed MC cable which keeps it watertight for direct burial in the ground. Just ask for MC cable with PVC jacket.
UFB cable stands for underground feeder with ground. This cable comes in the standard circuit sizes of 14 AWG through 6 AWG and comes in 2 or 3 conductors plus a ground wire. The ground is bare copper but the UF-B jacket is very strong and can handle the underground abuse.
These are the main types of electrical wire. However, they don’t necessarily encompass the wire that is most commonly used. Below are the most popular types of electrical wire.
1. Indoor NMB cable or Romex® 12/2 cable
NMB stands for non-metallic because it has a PVC jacket instead of a metal-clad jacket. It is a basic indoor electrical wire used to deliver power from an electrical box to lights, outlets and appliances. It cannot be used outdoors because the jacket is not prepared to handle wear and tear.
2. MC 12/2 Electrical Wire
These MC wires have interlocked armor surrounding the THHN wires. The aluminum armor also acts as a conduit when used for indoor applications. Many times NMB electrical wire is required to be installed within the conduit for indoor applications, but now MC cable can act as the electrical wire and conduit in one.
3. UFB 12/2 Electrical Wire
This UFB wire has the necessary protection to allow it to be buried in the ground without any additional conduit, raceway or tray. There is a slightly higher cost for UFB because of it’s additional capabilities compared to NMB cable and MC cable.
4. Tray 12/2 Electrical Wire
Tray cable is also a direct burial cable like UFB cable. However, UFB cable is “flat” which means each conductor lies next to each other as if they were lying on the floor next to each other. Tray cable is round which means the wires are slightly twisted together with the jacket surrounding them. Tray and UFB have slightly different applications so be sure to discuss each situation with your supplier or electrician first.
5. PLTC 12/2 Electrical Wire
PLTC stands for Power Limited Tray Cable. Power Limited means 300 volts instead of 600 volts. Simply saying “tray cable” will call out 600 volts. PLTC electrical wire is commonly used for electronic applications rather than electrical, but they have very similar attributes when compared to each other.
There are slight differences between each type of electrical wire. Putting the wrong type of wire in the wrong application could cause many problems such as a jacket eaten away too soon, too much voltage traveling through the cable or paying too much for your product because you didn’t understand enough about the cable characteristics. Now that you know which cable to use, you can ask your electrician which size you need for the amount of power.
When you’re ready to purchase your electrical wire for your business or home project, look no further than WesBell Electronics! We offer all of the above types of wire in addition to cables for other industries, wire services, and custom orders. Contact us to learn more or purchase wire in our online shop today!