12 AWG Wire: A Guide to 12-Gauge Wires

FACTS CHECKED BY  Jose George​

If you’ve previously handled a wiring project, you’ll agree it can be stressful and challenging, especially with the various wire sizes, such as the 12-AWG wire and 14-AWG wire. The job can seem unending and confusing, with every outlet and wire different from the other. 

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What Size Wire Is Needed For 200Amp Electrical Service – Home Inspection Insider

However, with the help of this article, you’ll likely have an easier time. 

Why Wire Gauge Is Important

Although fuses and circuit breakers prevent overloading and overheating, they protect wires from overheating by sensing current trips or overloads. However, it doesn’t mean the cables are completely safe.

Whenever a device draws more power from a circuit than the amperage rating of the wire gauge, there’s cause for alarm. For instance, if your course has an average of 15 amps with a 14-gauge wire, and you plan on plugging a 20-amp device, you’re likely to damage the circuit. 

And if the circuit breaker is faulty, it will fail to protect the wires from overheating to the point of melting the insulation or igniting the surrounding materials.

Damaged circuit

Caption: Damaged circuit

However, there’s no harm in plugging a device with a lower amperage into a circuit with a higher amperage rating and better gauge wires. The course will only supply the needed power to the device. No more.

Using lighthouse extension cords poses the highest threat. Often, home fires are sparked by extension cords when a device with a higher amperage and temperature rating is plugged in, causing the wires to overheat. 

Therefore, when purchasing an extension cord, it’s best to look for one with a higher amperage rating to serve your needs better.

A melted circuit starting a fire

Caption: A melted circuit starting a fire

12-Gauge Wire Understanding

This wire can handle a current of 10 to 20 amps, making it a favorite option for taking wiring car installations, extension cords, and speakers. However, depending on the wire temperature rating and length, the amount of current a wire carries differs. 

12-Gauge Wire Dimensions/Thickness

Typically, a 12-gauge wire measures about 2.05 mm (0.08 inches) in diameter and has a cross-sectional area of around 3.31 mm2 (0.005 inches2). Note, though, that these dimensions are for solid AWG copper wires. Stranded wires might feature slightly different sizes.

12-Gauge Wire Amps

The maximum wire temperature determines how much current 12-gauge wires can carry. Below is a more detailed description of what to expect:

  1. 1940F/900C – a maximum of 30 amps
  2. 1670F/750C – a maximum of 25 amps
  3. 1400F/600C – a maximum of 20 amps

Professionals recommend using a wire with a max of 20 amps for most appliances. However, it’s okay to opt for a higher amp rating in situations requiring more amperage. 

12-Gauge Wire Cables: 12/2, 12/3, and 12/4 Wire

Usually, electrical cables are separate wires grouped and arranged in a cable. It’s hard to find an individual wire being used. Therefore, cables are often labeled by the number of wires.

  • 12/2 (12’2) wire
  • 12/3 (12’3) wire
  • 12/4 (12’4) wire
  • Cables with more than four wires, although these are rare and often custom built.

The wires are permanently colored to help you differentiate between them so that you can wire them adequately. Different cables use different color codes to identify the separate wires. And these color codes vary from country to country.

The Applications of 12 AWG Cables

Industrial: In industrial settings, wire electrical motors. For devices or appliances with a higher power draw, 12 AWG wires are the perfect solution. These flexible and strong cables can be used in multiple ways, including: 

  • Communication and power distribution: Their application extends into the communication and power distribution industries.
  • Commercial: Here, you can use them in appliances, tools, and electronics.
  • Household: You can also use 12 AWG cables when wiring your house. Often in homes, 12 AWG wires are used for lighting purposes. Their small size allows the wires to fit and pass through any outlets or furniture. 
  • Automobiles: 12 AWG cables could also be used in car lighting. The plus side of using 12 AWG wiring in cars is that the wires occupy less space in the trunk or engine.
  • When planning for any commercial or residential settings, you can use 12 AWG cables. However, this mainly applies to small spaces, air conditioner connections, power supply, or installing speakers.
  • Sometimes 12 AWG cables are used with larger devices such as AC units and refrigerators.
  • Often, you’ll find 12 AWG cables used in electrical applications such as heating systems, power tools, and telephone lines.

Tips for Using the 12 AWG Cable

Because of their consistent performance and simplicity, most professionals and enthusiasts prefer the 12 AWG cables. However, it’s important to note:

  • 12 AWG cables aren’t amperage-rated for high voltages. Therefore, it’s best to avoid using these cables on power tools. 
  • They’re more straightforward to use as it’s easy to feed their small size into connections, so much so that you can often perform any wiring in your home without the help of an electrician, helping you cut costs.  
  • You can lay out the 12 AWG cables in various methods, with most of their uses applying a twist lock termination. Preferably when laying cables on the floor, you’ll need to use a stackable ending. But when laying multiple layers, a banana jack termination is more appropriate. 
  • Another reason for their widespread use is their availability in different colors that can easily be routed and securely attached.
  • 12 AWG cables are also suitable, mainly when covering the more considerable ground, since they offer more amps per foot. However, it’s essential to keep in mind their low amperage rating. You’ll encounter challenges finishing the task if the load on each wire is down. 
  • Often 12 AWG cables are about three feet long. Luckily you can opt for a more extended size.

12-Gauge Wire vs. 14-Gauge Wire: Which is Better for Outlets?

If you look at 12-gauge and 14-gauge wire sizes, cables for residential purposes have three wires. Two wires are classified as hot because they can conduct electricity. These hot wires will likely be in a black and white casing. The remaining wire is the grounding wire and will either be in a green or copper outer jacket. 

3 wire system

Caption: 3 wire system

Choosing the correct wire gauge for the job is vital, regardless of whether you’re wiring outlets at home or installing electrical wires for the first time at a site. Often professionals opt for the thicker 12 gauge wire for their wiring needs, with some occasionally opting for the 14 AWG cables. The reasons behind this include:

Better Safety

Compared to the 14 AWG cable, the 12 AWG is a larger wire with a higher temperature rating. Therefore, it can conduct higher amounts of electricity without the overheating and melting that could lead to electrical fires. It’s advisable only to use 14 AWG cables when wiring outlets that are expected to carry a power of 15 amps or lower. However, you can use the 12 AWG cable for 15 and 20 amps.

Increased Capacity

If no device has been plugged into a 20 amp outlet, it should be capable of allowing as many outlets as necessary without overloading the breaker. However, it’s best to have no more than ten outlets connected to a 12-gauge wire with a 20-amp circuit breaker. On the other hand, a 14-gauge wire can only allow a maximum of eight outlets.

Many branches

12-gauge wire allows you to add more devices to a unit.

Reduced Voltage Drop

Opting for a 12-gauge wire over a 14-gauge wire means fewer voltage drops if the wire covers a considerable distance.

Future Expansion 

With a 12 gauge wire, adding more outlets or branch circuits is easier.

One should put at least 10 gauge wire from the circuit breaker to the wall power outlet – very short 12 gauge wires can handle 16 Amps continuously with the maximum wire surface temperature of 60°C/140°F, but why is there the risk of overheating the cables?

Conclusion: 

Electrical wiring is meant to last a lifetime, and most do. However, this is only possible if you did the wiring correctly the first time. If the wrong wire gauge is used, it could result in short-circuiting, damaged insulation, popping out of breakers, and overheating, which could spark a fire. 12 AWG wires can serve a wide range of purposes. However, when doing electrical wiring, remember all the safety protocols. If you encounter any challenges, feel free to contact us.

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