2/0 Copper Wire: Ampacity, Weight, and More


Specific components play an indisputably pivotal role in electrical systems’ intricate and dynamic world. One such component is the 2/0 copper wire. Its impressive conductivity, robustness, and versatility make it essential in various electrical applications. From service entrance conductors to large appliance wiring, 2/0 copper wire helps power our daily lives.

If you’ve ever been curious about what makes this type of wire so special or how it stacks up against other wiring options, you’ve come to the right place. This comprehensive guide will walk you through everything you need to know about 2/0 copper wire, from understanding its gauge to exploring its current carrying capacity, how it fits into NEMA standards, and much more.

Understanding Wire Gauge: What Does 2/0 Mean?

Before diving into the specifics of 2/0 copper wire, let’s demystify the terminology. The term “2/0” (pronounced “two aught”) is part of the American Wire Gauge (AWG) system, which classifies wire diameter sizes.

In the AWG system, a smaller gauge number signifies a larger wire diameter. This might seem counterintuitive at first glance. However, it becomes more apparent when considering that the AWG numbers represent the steps involved in the wire-drawing process. Therefore, a larger number signifies a wire that has undergone more “draws” and is consequently thinner.

“2/0” signifies a wire that’s larger than 1 AWG. To be precise, it’s two steps larger, hence the term “two aught.” This puts 2/0 copper wire in the category of heavy-duty wire sizes, suitable for applications requiring substantial current carrying capacity.

How Much Does 2/0 Copper Wire Weigh Per Foot?

Now that you understand what “2/0” means let’s delve into the specifics of 2/0 copper wire.

One question that often arises when dealing with this kind of wire is: “How much does 2/0 copper wire weigh per foot?” The answer is approximately 0.4 pounds per foot. That number is based on pure copper and can increase by 15% or more depending on the insulation used. This weight is essential to consider when handling and installing 2/0 copper wire. This weight can significantly impact logistics and installation procedures in large-scale operations where thousands of feet of wire might be involved. For instance, support structures need to be robust enough to handle the weight, and safety measures for workers must be in place to prevent accidents during installation.

Regarding physical properties, 2/0 copper wire has a diameter of approximately 0.365 inches or around 9.3 millimeters. This makes it a fairly substantial wire capable of handling heavy-duty electrical tasks.

Basic Applications 2/0 Copper Wire

As for its applications, 2/0 copper wire is often used as a service entrance conductor. Service entrance conductors connect the electrical supply from a utility company to the home’s main electrical panel. Given the substantial amount of current these wires need to handle, the high ampacity of 2/0 copper wire makes it an excellent choice for this application.

In addition to service entrance conductors, 2/0 copper wire is commonly used to wire large appliances. These can include central air conditioning units, electric furnaces, and other high-demand equipment. The high conductivity and robustness of 2/0 copper wire make it well-suited for these applications.

2/0 Copper Wire Ampacity in the Standards

The National Electrical Manufacturers Association (NEMA) sets the standards for the manufacture of electrical equipment, including wire sizes like 2/0 copper wire. NEMA standards are essential because they provide guidelines that help to ensure the safety, reliability, and efficiency of electrical equipment and installations.

Specific NEMA standards apply to 2/0 copper wire, including the NEMA WC 70/ICEA S-95-658, which covers power cables rated 2000V or less. These standards set out the minimum requirements for the physical and electrical properties of the wire, including aspects such as insulation thickness, conductor diameter, and voltage rating.

Adherence to these standards is crucial. It not only helps to ensure that the wire performs its function effectively and safely but also guarantees that it is compatible with other components and equipment that follow these standards. Non-adherence to NEMA standards can lead to many problems, including safety risks, equipment damage, and inefficiencies. The standard I reference most, mainly due to it being open to the public, is NFPA 70.

Wire GaugeMax Ampacity (Amps)*Weight per Foot (lbs)**Approximate Diameter (inches)
*Please note that the current carrying capacity depends on the insulation type and temperature rating of the wire. PLEASE CONSULT NFPA 70 BEFORE USING ANY OF THE VALUES SEEN HERE.
** The weights/ft shown here may not be found anywhere else online.  I was frustrated with the different results I found, so the weights here were calculated from the approximate diameter and density of copper.  The weight was calculated as weight = volume (a function of diameter) * density of copper

What is NEMA, and What is NFPA?

The National Fire Protection Association (NFPA) and the National Electrical Manufacturers Association (NEMA) are two distinct organizations that play crucial roles in setting safety standards within the United States.

NFPA is a nonprofit organization devoted to eliminating death, injury, property, and economic loss due to fire, electrical, and related hazards. They achieve this by providing and advocating consensus codes and standards, research, training, and education. One of their most recognized publications is the National Electrical Code (NEC), a standard for the safe installation of electrical wiring and equipment in the United States.

On the other hand, NEMA is an association of electrical equipment and medical imaging manufacturers. They provide a forum for standardizing electrical equipment, enabling consumers to select safe, effective, and compatible electrical products. NEMA standards often deal with product design, production, and distribution.

While both organizations are involved in setting safety standards, their roles differ. NFPA focuses on creating comprehensive safety codes and standards, while NEMA focuses on standardizing electrical equipment manufacturing. In the context of electrical wiring, NFPA’s NEC might specify the types of wiring that can be used in certain situations, while NEMA standards might define the physical and electrical characteristics of that wiring.

These organizations often work in concert. For example, NEMA might develop a standard for a certain type of electrical equipment, and NFPA might reference that standard in its codes, making it a requirement for certain types of electrical installations. In this way, the work of these two organizations is closely intertwined in the pursuit of electrical safety.

Current Carrying Capacity of 2/0 Copper Wire

Solar panels require heavy duty wiring to transfer power from the roof to the rest of the home.

Ampacity, or current carrying capacity, is a critical property of electrical wires. It refers to the maximum amount of current that a wire can safely carry without exceeding its temperature rating. Various factors influence ampacity, including the conductor material, ambient temperature, and insulation type.

For 2/0 copper wire, the ampacity is quite significant due to copper’s high conductivity. Under ideal conditions with the right temperature-rated insulation, 2/0 copper wire can carry up to 195 amps, as shown in this old but good chart based on NFPA 70. This high ampacity is why 2/0 copper wire is often chosen for heavy-duty applications such as service entrance conductors.

However, it’s important to note that the actual ampacity can vary depending on the installation conditions. For example, if the wire is installed in a hot environment or in a conduit with multiple other wires, the allowable ampacity may need to be derated to prevent overheating.

2/0 Copper Wire Heat Dissipation

In any discussion about electrical wires, heat dissipation is a crucial aspect that cannot be overlooked. As electric current flows through a wire, it generates heat due to its resistance. The ability of a wire to dissipate this heat effectively is vital for its safe operation.

Copper, including 2/0 copper wire, is known for its excellent electrical conductivity and superior thermal conductivity. This means that copper wire can effectively reduce the heat generated when current flows through it. This property makes copper wire less likely to overheat than other metals, even when carrying high current loads.

However, it’s important to note that heat dissipation also depends on other factors, such as the wire’s surface area, the surrounding temperature, and airflow. For instance, a wire bundled with other wires or enclosed in a conduit may not dissipate heat as effectively due to restricted airflow.

Regarding 2/0 copper wire, its large diameter provides a substantial surface area for heat dissipation. However, care should still be taken to ensure that the wire is installed in a manner that allows for effective heat dissipation. This might include avoiding bundling the wires too tightly and ensuring that enclosed spaces are adequately ventilated.

In addition, due to the substantial ampacity of 2/0 copper wire, it’s crucial to ensure that the wire is not overloaded. Overloading the wire can cause excessive heat generation, which may overwhelm the wire’s ability to dissipate the heat, leading to overheating and fire. Adherence to NEC guidelines and safety standards is paramount when installing and operating 2/0 copper wire.

While copper’s excellent heat dissipation is a significant advantage, it doesn’t negate the need for correct installation and operation to ensure safety and efficiency.

Safety Considerations with 2/0 Copper Wire

Conduit.  What could be inside? 2/0 Copper Wire?  Magic smoke?

Given its size and current-carrying capacity, handling and installing 2/0 copper wire requires careful attention to safety. Below are some critical safety considerations to consider when working with this type of wire.

  • Proper Installation: Ensuring the 2/0 copper wire is correctly installed is paramount to its safe operation. This includes ensuring the wire is adequately supported and secured to prevent physical damage that could lead to electrical hazards. Incorrectly installed wire can also lead to problems like electrical shorts and overheating.
  • Correct Ampacity: It is vital to ensure that the wire’s current-carrying capacity is not exceeded. Overloading the wire can lead to excessive heat generation, which, if not properly managed, could lead to a risk of overheating and fire. Always adhere to the ampacity guidelines provided by NEC for safe operation.
  • Insulation Integrity: The insulation around the 2/0 copper wire plays a crucial role in preventing electrical shorts and protecting the wire from physical damage. Inspecting the insulation regularly to ensure it is intact and replacing the wire if any damage is detected is important.
  • Appropriate Protective Equipment: Personal protective equipment is crucial when installing or maintaining 2/0 copper wire. This can include gloves to protect against cuts and abrasions, safety glasses to shield the eyes from flying debris, and insulated tools to protect against electric shock.
  • Proper Training: Handling and installing 2/0 copper wire should only be done by individuals who have received the appropriate training. This will ensure they understand the risks involved and the precautions they need to take to work safely.
  • Adherence to Codes and Standards: Adhering to the guidelines of NEMA and NEC is vital when installing and operating 2/0 copper wire. These codes and standards have been developed to ensure electrical systems’ safe and efficient operation, and non-compliance can lead to serious safety risks.

In summary, safety should always be a top priority when dealing with 2/0 copper wire. From correct installation and operation to the use of appropriate protective equipment and training, taking these precautions can go a long way in ensuring the safe and efficient use of 2/0 copper wire.

Buying Guide for 2/0 Copper Wire

Investing in 2/0 copper wire involves careful consideration of several factors. To ensure you’re making an informed purchase, here are some key aspects to look out for:

  • Weight: As discussed earlier, 2/0 copper wire weighs approximately 0.643 pounds per foot. When planning your project, factor in this weight, especially for large installations where the cumulative weight can significantly affect logistics and installation procedures.
  • Ampacity: Consider the electrical load the wire must carry. As we’ve seen, 2/0 copper wire has a high ampacity and can carry up to 195 amps under ideal conditions. However, various factors can influence this capacity, so account for these in your calculations.
  • NEMA Standards: Always ensure that the 2/0 copper wire you purchase meets NEMA standards. This guarantees its quality, safety, and compatibility with other electrical components.
  • Supplier Reputation: Finally, always buy from reputable suppliers who can guarantee the quality and safety of their products. Reputable suppliers will also be able to provide the necessary documentation to demonstrate that their wire meets NEMA standards.


As I wrap up this in-depth exploration of 2/0 copper wire, there are several key takeaways to keep in mind:

  • Current Carrying Capacity: The 2/0 copper wire has a high ampacity, making it suitable for transmitting large amounts of electrical power over considerable distances. It is commonly used in both residential and commercial applications for power distribution.
  • Weight: With an average weight of approximately 0.4 lbs per foot, 2/0 copper wire is certainly not lightweight. This can influence the handling, transportation, and installation processes. However, its weight is a testament to its robustness and high carrying capacity.
  • Heat Dissipation: Copper’s superior ability to dissipate heat compared to other metals, such as aluminum, is a crucial factor in preventing overheating and potential fire hazards. It’s a critical factor to consider, especially in systems with high electrical loads.
  • Safety Considerations: Adherence to NEMA standards ensures that your wiring system is safe and capable of performing to its maximum potential. Always consult with a qualified electrician who understands these standards when installing or upgrading your electrical system.
  • Copper vs. Aluminum: While aluminum may be lighter and less expensive than copper, copper’s superior conductivity, heat dissipation, and tensile strength make it an excellent choice for many applications. However, the specific requirements and constraints of your project may favor one over the other.
  • Wire Gauge: Remember, the wire gauge is inversely proportional to the wire’s diameter. So, a 2/0 wire is thicker than a 1/0 wire, which is thicker than a 1 wire, and so on. Thicker wires have higher current carrying capacities and are heavier per foot.

In conclusion, choosing the right wire for your project involves balancing several factors, including ampacity, weight, heat dissipation, and safety considerations. Understanding these elements will help you make an informed decision that matches your specific requirements and optimizes the performance of your electrical system. And before you leave, please be sure to check out other related articles at The Voltage Drop!

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