Understand the different types of wires and cables

With our homes running on more electricity than ever before, a basic understanding of the cables and wiring in your home is vital. 

Use this sheet to learn about a variety of different cables before starting your next electrical project.

Cable and Wire Safety Tips

When working with something as sensitive as electricity, safety should be your primary concern. 

Here are some simple safety tips to keep in mind to avoid common electrical mistakes.

Always follow the manufacturer’s recommendations for using cords outdoors and never use a household extension cord outdoors. 

I should replace damaged or worn extension cords, never repaired. 

Also, you will want to replace older cables that are not polarized and do not have safety clasps because they present a safety risk.

 On the reverse, you never want to remove the third prong or cut the prong off a plug to fit a nonpolarized receptacle.


Before plugging anything into an extension cord, you should always know the length of the cord needed and the electrical load it can carry. 

The cord should easily reach from the wall outlet to the device without voltage, and you should never put two short cords together to get the required length. Just go out and buy a new cable of the proper length.

Only use an extension cord that a nationally recognized testing laboratory such as UL, CSA, or ITS has tested. 

This should be shown on your cable label or molded into the end of the cable, depending on how new it is. 

The cable must also be permanently attached to the plug and connector to request a good connection and no cables required. 

Defective cables do not go through inspection, but some do. If your cable is not securely attached, throw it away or return it to the store for a new one.

 Keep cables out of the reach of children and out of high-traffic areas where people can trip over them. 

Not only is this a safety hazard, it could damage your cord or socket if someone’s foot fixes the cord. 

Also, never cover cords with rugs, furniture, or appliances. If you’re having trouble keeping your cables out of the way and under things, consider rearranging your room.


The cable itself differs from the cable. Cable actually refers to two or more cables or conductors bundled together in a jacket.

 Gauge number, from 0000 to the groups the wire number 40. The smaller the number, the thicker the wire. 

For home use, the most common meters are between 10 and 20. While the larger wire carries more current, forcing too much current through a wire will cause it to overheat and trip a switch. 

A larger cord is also unnecessary for home use. The most common conductor in household wiring is copper or tinned copper because it has a minimal resistance at a reasonable cost.

Letters that correspond to the type of insulation and electrical capacity also characterized the wire.

The ground wire provides a path of least resistance from the frame or casing of an appliance to the ground to prevent electrical shock.

 Two-conductor and three-conductor cables can carry ground wires.


As stated earlier, cable refers to a collection of two or more strands of wire or conductors.

 Basically, the cable has a “hot” line to carry the current and a “neutral” line to complete the loop. They also usually have a third wire, that ground wire.

Cables are classified according to the number of cables they contain and their size or gauge. All cables are marked with a series of letters, followed by a number, a guide, and another number. 

The letters show the type of insulation (cable, wire and insulation). The first number shows the resistance of the wires in the cable, and the number following the dash shows the number of individual conductors in the cable. 

If the designator “G” follows the string, it means that it also equipped the cable with a ground wire that does not carry current. 

So, for example, the USE 12-3 / G designator shows an underground cable that contains three separately insulated cables carrying 20 amps of current plus a ground wire.

 There are several specific types of cable that are specifically used. The two-conductor cable contains one black wire and one white wire. 

The black wire is always the “hot” wire and must be fused. White is always neutral and should never merge. 

When the current closes the gap between the 110V hot wire and the neutral, it generates a 110V input to the device.

The three-conductor cable contains a red cable besides the black and white.

 The black and red wires are “hot”, carrying 110V each, and it should fuse both, while the white remains neutral. 

This three-wire circuit is becoming more and more common in home wiring; It has a capacity for the main 220V appliances, such as kitchens and air conditioners.

The BX cable is shielded, metal cable. It comprises two or three insulated wires individually wrapped in layers of spiral paper.

 The steel housing acts as a ground wire. There is also a link cable included if acts as a ground if the case breaks.

Romex ™ cable has a flat beige thermoplastic jacket that surrounds two or three cables. They wrapped each wire in insulation and a spiral paper tape. 

Type NM means it can be used indoors. The NMC type means that it can be used indoors or outdoors. Type UF means it is suitable for use underground in the open air.

The most common functions for cable are NM-B (indoor non-metallic construction), UF-B (underground feed), and BX, which is a flexible metal cable.

Now, let’s look at some more specific types of wiring and cable that you will see around a modern home.

Thermostat wire

I used the thermostat cable in low voltage communication, alarm and control systems. 

The most common types of this cable are braided, twisted, and plastic jacketed types; however, all three use solid copper conductors and are twisted and plastic insulated.

The stranded wire, which has no external braid, is used in doorbells, burglar alarms, intercom telephones, and public address systems, while the stranded wire is covered with cotton braid and is mainly used in thermostat controls and other control circuits. remote low voltage. 

They also used plastic jacketed cable in low voltage applications similar to stranded cable.

 Although the thermostat wire is low voltage, it is UL Listed for being flame retardant as it is installed in the wall. 

Wiring used in smoke detection and security alarm systems must be UL listed.

TV cable and accessories

The TV input cable connects the receiver to the antenna. A good quality 300 ohm cable is used for VHF and UHF receivers. 

A TV coupler is a glossy device for connecting two or more TV receivers to the same antenna. 

The loss introduced in the circuit is small, but it can be critical in the reception of the “marginal area”.

 In short, inform customers of this slight loss and expect a slight reduction in signal strength at the receiver.

A lightning rod is installed outside the house as close as possible to the TV receiver to protect it from lightning damage. 

I connected the input cable to the connected contacts and the ground bar connector. 

Someone instal correctly the rays that jump the space inside the arrester and flow towards the ground if the circuit.

Home networks

Home networks connect multiple home computers, satellite dishes, cable television, and sophisticated audio systems

The heart of these systems is the network center. Though with computers, the home network hub differs because it provides central control of computers, peripherals, telephones, televisions, and audio components.

 This is the unit where most of the wiring from different locations comes together to meet.

Most home networks use coaxial cable, Category 3 and Category 5. Coaxial cable is used for televisions, VCRs, and satellite equipment.

 I used category 3 cable for telephones, while Category 5 is used for telephone, fax, and computer systems. Some cables will combine different functions in one cable.


“Structured” cabling refers to a bundle of cables that runs from the network hub to meet the future information transport needs of a home.

 This cable bundle can comprise a combination of Category 5 cables, fiber optic lines, Category 3 cables, and coaxial lines.

The jacks are used to end the cable. There are different connectors for telephones, computers, satellite equipment, audio and video. 

Many of these cable jacks and connectors require special tools for installation.

Patch cables are used to connect different computers and audio / video devices to each other or to a central network device, such as a hub.

The binding posts are used to connect the stripped speaker wire, while the F connectors are used with coaxial cable.

Extension cables

Indoor extension cords come in two-wire cords and in lengths from 6 ‘to 15’. White and brown are the basic colors, with occasional outliers. 

We used outdoor extension cords for outdoor power tools and outdoor lighting, such as seasonal decorations.

 They come in 16/3, 14/3, and 12/3 cable, with the most common lengths ranging from 25 ‘to 100’. I should use heavy duty extension cords with high voltage appliances. These are commonly orange in appearance.

Any UL certified cable will carry a UL label near the female end. Many companies are now using an alternative UL-permitted labeling method, which allows UL marks to be molded into the ends of the cable. 

This guarantees a permanent mark that cannot be provided with a label. It is important to verify this UL insignia, whether it is a label or a permanent mark.

 Unlisted cables may be similar in appearance to the listed ones.

To be UL Listed for outdoor use, round three-wire cables must have a connector and cap molded to the cable and a lip on the end of the connector to prevent misuse. 

Beginning in 1998, UL listed outdoor cables appeared with the “SJTW” mark on the cable, not “SJTW-A” as previously used. For a period, either brand will be acceptable for outdoor use.


Grounding cables are available in both heavy-duty and heavy-duty construction, which differs from standard cables in that they have three conductors instead of two and are equipped with a three-prong grounding plug and connector.

The pass-through safer cables have built-in pendant switches to control appliances and lamps throughout the room, and the rope reels keep cables tangled and trapping from the floor for ease of use.

Appliance cords

Home appliance cables combine the cable and the connector. The difference between the cable assemblies may be in the type of connector and / or cable used. 

There are also free end clamp cable sets without connectors that are used to rewire direct clamp irons, toasters, and similar small appliances.

 They have pre-tinned ends to speed up wiring.

Range and dryer cords

Range and dryer cables are free-standing type, commonly called “pigtails,” connected directly to the appliance.

 I equipped the free ends with wire plugs that connect to the screw terminals of the apparatus to ensure positive connections. 

A metal clamp attached to the cable serves as a strain relief at the point where the cable enters an appliance and a cable protector.

Heavy-duty kitchen and dryer plugs are much larger than standard plugs.

 Most are “L” shaped with a power cord coming out of the plug side. Sizes vary from 30 to 50 amps for various dryer models and ranges. 

The different amperage connection plugs are not interchangeable because of a difference in their configuration.

A recent change in the National Electrical Code requires the new range and drying receptacle installations to be 3-pole, 4-wire grounding receptacles. 

The neutral (grounded circuit conductor) can no longer be used to ground the frames of electrical ranges and dryers.

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