What Size Wire for 30 Amps?

30 amp extension

For outdoor or heavy-duty 30 amp outlets, air conditioners or other large appliances, use 10-gauge wire for up to 150 feet. The National Electrical Code (NEC) recommends 12-gauge wire for circuits that are general purpose.

What is 30 amp wire size?

30 amp wire size is a type of electrical wire that can carry up to 30 amps of electricity. It is typically used to power large appliances and devices, such as electric dryers, ovens, and ranges. 30 amp wire size is also used to power RVs and travel trailers.

A certified electrician is necessary for handling these types of amperages and wiring.

What is 30 amp wire used for?

30 amp wire size is used for a variety of applications, including:

  • Electric dryers
  • Ovens
  • Ranges
  • RVs
  • Travel trailers
  • Generators
  • Large power tools

How to choose the right size 30 amp wire

When choosing 30 amp wire size, it is important to consider the following factors:

  • The amperage of the appliance or device you are powering.
  • The length of the wire run.
  • The type of electrical load.

It is also important to use the right type of wire for the application. For example, 30 amp wire size should be used for 30 amp appliances and devices.

What Are The Dangers of Using the Wrong Wire Size?

Using the wrong wire size can be dangerous. When you use a wire that is too small, it can overheat and cause a fire. When you use a wire that is too large, it can be a waste of money.

Here are some of the dangers of using the wrong wire size:

  • Fire. Overheating wire can cause a fire. This is a serious hazard that can damage property and cause injuries.
  • Electrical shock. A wire that is too small can overheat and cause an electrical shock. This can be fatal.
  • Overload. A wire that is too small can overheat and cause a circuit breaker to trip. This can inconvenience you and disrupt your electrical service.
  • Waste of money. Using a wire that is too large can be a waste of money. You will pay more for the wire and you will lose power efficiency.

How Do You Size a Gauge Wire?

To size a gauge wire, you need to know the amperage of the appliance or device you are powering. The amperage is listed on the appliance or device. Once you know the amperage, you can use the following chart to determine the correct wire size:

Amperage Wire Size
0-15 14 gauge
15-20 12 gauge
20-30 10 gauge
30-40 8 gauge
40-50 6 gauge
50-60 4 gauge

What Is the 80% Rule for NEC?

The 80% rule is a safety guideline that is set by the National Electrical Code (NEC). The rule states that the total amperage of all the appliances and devices on a circuit should not exceed 80% of the circuit's amperage rating.

For example, if you have a 30 amp circuit, the total amperage of all the appliances and devices on the circuit should not exceed 24 amps.

The 80% rule is designed to prevent overloading circuits, which can cause fires.

Tips on Installing Wire for a 30 Amp Breaker

  • Choose the right wire size. The National Electrical Code (NEC) recommends using 12-gauge wire for general purpose circuits. For outdoor or heavy-duty outlets, use 10-gauge wire. For circuits that run through more than one room, use 14-gauge wire. For air conditioners or other large appliances, use 10-gauge wire.
  • Use the right tools. Wire stripper, a wire crimper, and a screwdriver.
  • Strip the insulation from the ends of the wire. Be careful not to cut the wire.
  • Crimp the ends of the wire. Make sure the crimps are tight.
  • Connect the wire to the breaker. Follow the instructions that come with the breaker.
  • Test the circuit. Turn on the breaker and make sure the circuit is working properly.
  • Always follow the National Electrical Code (NEC). The NEC is a set of safety standards that must be followed when working with electrical wiring.
  • Be careful not to overload the circuit. Overloading a circuit can cause a fire.
  • Use a surge protector. A surge protector can help to protect your appliances from power surges.
  • Have a qualified electrician install the wire if you are not comfortable doing it yourself. Installing electrical wiring can be dangerous if you are not experienced.

Where to buy 30 amp wire

30 amp wire can be purchased at most hardware stores and home improvement centers. When purchasing 30 amp wire, it is important to choose a reputable brand and to make sure that the wire is UL-listed.

Here are some 10 Gauge wires and extensions on amazon:

Amperage capacities for standard non-metallic (NM) cable

Amperage Wire Size
95 2 gauge
85 3 gauge
70 4 gauge
55 6 gauge
40 8 gauge
30 10 gauge
20 12 gauge
15 14 gauge
13 16 gauge



Stay updated with our newsletter

Related Posts


You just learned that the best wire for 30 amps is a 10-gauge wire. This wire should however be upgraded to 8-gauge or thicker if you gon over 150 feet. If you see any errors in this or any other articles on this blog, please feel free to point them out. I will appreciate it.

About Author:

image of Kevin Pommells

Hi, I'm Kevin Pommells, a lover of camping and the great outdoors as everyone says nowadays. I'm also a passionate soccer fan and the proud owner of CamperRules.com, a website dedicated to helping campers and outdoor enthusiasts make the most of their adventures. With years of experience exploring the wilderness and a deep love for the sport of soccer, I'm always looking for new ways to combine my two passions and share my knowledge with others. Follow me for tips, tricks, and insights on all things camping and outdoor recreation.

Follow Me @ Twitter | Facebook

As an Amazon Associate I earn from qualifying purchases.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.