The best wire size for a single-phase 120/240V 80 Amp circuit is 4 AWG copper wire (85 Amps ampacity at 75°C) and 2 AWG aluminum wire (90 Amps ampacity at 75°C). These sizes are recommended for a maximum run of 100 feet. 

The 80 Amp wire size for distances up to 200 feet is 2 AWG copper wire and 1/0 AWG aluminum wire because of the voltage drop.

Smaller sizes, like 6 AWG copper, cannot handle 80 Amp service. Remember that the 80 amp wire size may also depend on the regional standards in your area.

The Applications of 80 Amp Breakers

80 Amp breakers are quite versatile and can be used for a wide range of commercial, industrial, and residential applications. Here are some of the common uses of an 80 Amp breaker:

• Residential Electrical Panel: In some residential electrical panels, an 80 amp breaker may be installed to provide power to a specific circuit or set of circuits. This could include larger appliances such as electric stoves, water heaters, or high-power electric dryers.
• Subpanel Distribution: An 80 amp breaker can be used in a subpanel to distribute power to specific areas or sections of a building. This is common in larger residential properties or commercial spaces where the main electrical service is divided into smaller subpanels for improved load distribution.
• Industrial and Commercial Applications: In specific industrial or commercial settings, an 80-amp breaker can protect circuits that supply power to machinery, equipment, or systems. These devices include motors, HVAC systems, lighting systems, and heavy-duty electrical loads that require higher amperage.
• Large-scale lighting installations: 80-mp breakers are common in large lighting systems for stadiums, theaters, and concert venues. In these applications, 80-amp breakers support lighting fixtures and lighting control systems.
• Dedicated Circuits: An 80 amp breaker is suitable for dedicated circuits for equipment and appliances. Some of the equipment that may require a dedicated circuit with an 80 Amp breaker is:
• Commercial refrigeration units
• Industrial ovens
• Lighting installations
• Fast-charging electric Vehicle (EV) charging stations
• Industrial equipment: large motors, pumps, compressors
• Welding equipment
• HVAC systems
• High-amp data center equipment, such as servers and cooling systems.

Types of Cables for 80 Amp Breakers

80-Amp breakers successfully use both copper and aluminum cables. The exact type of cable depends on the settings where the cables are installed. Some industrial circuits need specific industrial cables. For example, industrial ovens need cables with high-temperature PTFE insulation. However, here is the list of most popular copper and aluminum cables for 80-amp circuit breakers:

• THHN/THWN (copper and aluminum). This is the most popular option for 80-amp circuit breakers. The single-conductor wires are used in conduit. The applications include residential electric panels, subpanels, commercial installations, commercial refrigeration units, and HVAC systems.
• XHHW (aluminum/copper) is the most common cable for 80-amp breakers utilized with industrial equipment, such as motors, pumps, and compressors.
• MC metal-clad cables give the added benefit of extra mechanical protection. In the context of 80-amp breakers, they are most commonly used with large-scale lighting systems.
• SER service entrance cable can connect an 80 amp circuit breaker in a residential electric panel and be used for a subpanel distribution.
• USE-2 (underground service) and Triplex and Quadruplex URD Cables can be used for underground 80 Amp installations when allowed or required.