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What Size Wire For 80 Amp Breaker? (Read This First)

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Electrical wiring must observe specific precautions for it to be safe and valuable. Using the right size of wires for any electrical installation is one of the vital precautions you need to take.

The wire size also determines the amount of current it can transmit. So, if you intend to get an electrical wiring installation, this article is for you.

This article will explain the basic things you need to know concerning the wire size for your 80 amp breaker.

The 80 amp breaker generally needs a 4-gauge wire for efficient functionality. The 4-gauge wire is thickset enough to handle the circuitry power of the 80 amp breaker. When dealing with copper or aluminum, the wire size varies.

What Size Of Wire Do I Need For An 80 Amp Breaker?

What Wire Size For 80 Amp Breaker

A 4AWG is for transmission of 80 amps. However, the wire size varies because of certain factors, such as temperature and material.

The 4-gauge wire is the most suitable because it transmits 80 amps without overheating. It is of utmost importance that you use the correct wire for electrical connections.

Failure to use the suitable wire for 80 amps can get disastrous. Voltage, temperature, and distance determine the required wire size.

80 amps provide enough power to run most household machines, such as furnaces, water heaters, etc.

These heavy-duty machines use lots of power, which the 80 amp circuit delivers. To effectively distribute this high amount of current, the 80 amp must use a thick wire. 

Generally, a larger wire carries a more significant current. If you put a small wire to distribute a large current, it becomes a fire hazard.

Technically, 80 amps support many high current machines; it would help if the wire used is large and thick enough. 

You must consider the current traveling distance when picking a specific wire size. Resistance increase is directly proportional to distance increase.

Therefore, it would help to select a wire suitable for the distance. Resistance increase affects not only the distance but also the voltage. 

In addition, the quantity of current flow in the wire determines how much heat generates. When resistance increases, the production of heat will also increase.

The thickness of the wire proves helpful in this case because it will be able to contain a high volume of heat. On the contrary, you’ll risk a fire outbreak if the wire is small.

The wire gauge is a representation of its diameter. Some wires come with their gauge labeled on them; however, if it is not so, you have to measure the cross-section diameter.

There are thickness tools you can use to measure your wire gauge. An experienced professional should be able to help you get the exact wire you need. 

It would help to note that the higher the gauge number, the smaller the wire size; the lower the gauge, the thicker the wire.

The 80 amp breaker can also use 2 AWG or 3 AWG when using copper as the material. If the material is aluminum, it will require 1 AWG.

On the contrary, the standard wire measurement for your 80 amp breaker is 4-gauge.

What Is the Size of Copper Wire Okay for an 80 Amp Breaker?

Voltage and distance are priorities before setting the exact wire size for copper.

Generally, the standard wire size for copper is a 2 AWG or 3 AWG wire. In addition, copper Wire can carry more current due to its sturdy nature.

Most people don’t opt for copper because of its high price. For the 80 amp circuit, you can use a 4-gauge copper wire.

Before efficiently using a copper wire, you must observe specific things. Firstly, all the hot, neutral, and ground wires must be the same size.

That means the ground must follow suit if the hot and neutral are 4-gauge. For personal safety, you must not overlook this necessary precaution. Additionally, the amp wire size should be thicker than the ground wire.

Table Showing Variation Of Copper Wire With Voltage And Distance

The chart clearly shows how different voltages and distances affect the wire gauge. Note that temperature also affects the gauge.

Greater distance requires more thickset wires to safely transport the corresponding voltage without causing a fire

What Is the Size Of Aluminum Wire Okay for 80 Amp Breakers?

In the technical sense, the amp capacity of aluminum is lower than copper because aluminum requires a 2-gauge or 1-gauge wire.

This wire size can be affected by temperature, voltage, distance, and other factors.

Most people prefer using aluminum because it is inexpensive. However, aluminum carries a lesser current if you have aluminum and copper of the same gauge.

Therefore, your aluminum has to be of a high gauge to be able to support the 80 amp circuit. Therefore, use a 4 or 3-gauge wire when aluminum has to accommodate an 80 amp breaker.

How Do You Wire an 80 Amps Sub Panel?

It is essential to be careful when installing a circuit breaker in your home. Using the accurate wire size is just a step in ensuring you’re free from electrically induced hazards.

Another vital step is the proper wiring installation. Finally, the subpanel reduces the bulk load from the primary service circuit.

You must follow the proper procedure when wiring your 80 amps subpanel. It would help to note these things before you begin wiring the subpanel:

  • First, an electrical inspector must check that your installation will not overload your house’s electrical system.
  • Please note that the subpanel has different parts for the wires to be connected. Therefore, the inspector must check the subpanel and confirm it is the right one.
  • Switch off the service panel main breaker. 
  • An electrician should check the amount of load your subpanel can take before installation.
  • Put on protective gear.

You’re going to need some tools and materials to enable your wiring; they are:

  • Flashlight
  • Screwdriver
  • A hammer
  • Voltage tester
  • Wire strippers or utility knife
  • One lineman’s pliers
  • A long-nose plier
  • The required subpanel
  • One suitable feeder breaker
  •  Breaker for the circuit
  • A compatible feeder cable
  • Cable clamp
  •  Mounting screws

After assembling all the necessary types of equipment and materials, these are the steps to follow:

#1. Mount the Subpanel

 Mark a convenient position a foot (0.30m) from the main service panel, place the subpanel in the mounting screws and tighten.

Next, use the screwdriver to fasten the sub panel to the wall. The position is close to the main panel because it is needed to accommodate extra circuits the main panel can’t. 

Pull wires through the spaces in the subpanel, adding cable and sheathing where required.

Use pliers to remove the knockout slug. Slide your wires through the knockout slug and clamp the cable.

#2. Plan Route

Plan the ground route, neutral, and two hot wires at the main panel. Remove the knockout slug, strip the sheathing and clamp the cable.

Ensure the ground and neutral wires’ routing is done correctly to their respective bus bars.

The wiring has to get done orderly so that it doesn’t rub against the hot wire bus bars as this could cause a fire.

Also, the wires route should be clear; that way, it’d be easier to determine which wire goes in which breaker.  

#3. Strip the Wires

After routing, cut and strip the two hot wires (red and black). Next, connect them to the feeder breaker and bend the breaker into place.

#4. Connect the Wires

Cut, strip, and route the feeder wires (hot red and black) in the subpanel and connect them to the terminals.

You then connect the hot red and black wires to the hot bus bars. Finally, it would be best if you connected the ground wire to the ground terminal and the neutral to the neutral terminal.

#5. Final Wiring

The circuit cable should be run through the sub panel and clamped to validate the connection.

Next, connect each circuit route wire to the corresponding terminal or bus bar. Finally, switch on the feeder breaker to confirm if your subpanel is working.

As we discussed earlier, the wire you select must be compatible with the 80 amp circuit for it to serve you well.

If you’re a novice at electrical wiring or installations, it would be best to contact a licensed electrician. 


Using the appropriate wire size is an electrical precaution you should never ignore. Going for a cheaper option may prove disastrous for you.

It would help to take expert technical advice regarding electrical wiring installations. You can always employ the services of an electrician if you can’t handle the wiring.

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