When installing a 200 amp wire on your premises, your wire must support the same current load. If you use a bigger gauge wire, it may be hard to route during installation and incur unnecessary expensive expenses. On the other hand, if you select a smaller gauge wire, it and the insulators may burn and cause losses. Luckily, I have compiled a guide to help you choose the appropriate 200 amp wire gauge.
What Wire Size Works Best for 200 Amp Service?
To understand the wire size for your 200 amp service, consider several factors and regulations. First, you must determine the wire material you use, as different materials come with different gauges. Then, you have to follow the National Electricity Code (NEC) to ensure the effectiveness and safety of your wire choice. Here, we will discuss the different materials available and the NEC wire gauge specifications for them:
Wire Strength and Material
For the wire strength and material, you have either copper, aluminum, or copper-clad. According to the NEC specification, when you choose aluminum, a wire gauge of 2/0 AWG is best for your 200 amp. However, for copper clads and copper, the electrical installation regulation body recommends you go for 4/0 AWG.
Electrical wires
Copper
If you choose copper, you’ll pay more than you would for other materials. However, copper is heat—and corrosion-resistant, making it long-lasting and safe.
The material also bends easily, making it seamless to wire and route. What’s more, copper’s high electrical conductivity results in efficient power transmission with minimal current drops.
Aluminum
Those choosing aluminum or copper cladding expect it to be more cost-effective than copper. While it is not as good a conductor as copper, it is also highly conductive in electrical terms.
Aluminum is also very lightweight and easy to bend, making it a good material for complicated wiring. The only downside of this metal is that it is prone to corrosion, reducing its life span.
Grounding Wire
Your Grounding wire links your connection to the ground, ensuring the safety of your building. You can choose copper, aluminum, or copper-clad ground with different wire gauges. For example, if you go for copper, you go for 4 AWG; for aluminum, 2 AWG is the best.
Types of Cables
SER cables
You can use SE (service entrance) cables to connect your building’s main distribution to electricity service from the utility. SE cables for 200 amps mostly feature two insulated conductors, a neutral wire, and a bare or insulated grounding wire. Below are some examples of SER cables but I recommend contacting your local electrical regulation to learn the exact specifications.
- SER copper cable: A 200 amp service size is 2-2-2-4 SER. Here, it means one grounding (bare or insulated), one insulated AWG 2 neutral, and two insulated hot wires.
- Aluminum SER Wires: A typical code for an aluminum SER cable for 200 amp service is 4-4-4-6. This code means AWG 4 four insulated conductors, 4 AWG insulated neutral wire, and 6 AWG insulated or bare grounding.
USE 2 cables (underground service entrance)
As the name suggests, these are cables that you can run underground from a utility distribution system to your premises. Although they use the same coding as the cables above, they can withstand harsh weather, such as water and sunlight.
Standard Copper wires
Pros and Cons Between Copper and Aluminum
Copper
If you use copper, expect it to be corrosion-resistant, highly conductive, heat-resistant, bend easily, and good for long distances. However, it is very expensive and very heavy.
Aluminum
For aluminum, the wires are affordable, lightweight, and easy to install. The bad news is that they are vulnerable to heat and corrosion, which shorten their lifespan. They are also hard to repair and may not be compatible with some connectors.
Copper-clad aluminum wires
For those who opt for copper-clad aluminum, you may expect it to be corrosive-resistant, lightweight, and cost-effective. However, copper-clad aluminum has a lower conductivity than copper and is very soft, making it easily damaged.
A cross-section of aluminum wires
Other Factors to Consider
Cost
Like in any other project, the cost of the wire must be your priority. However, you should balance the initial cost, future repairs, and functionality. In this regard, copper is very expensive but does not need occasional repairs. On the other hand, aluminum is cheaper but susceptible to damage meaning you may spend more repairing it.
Voltage drop
As the name suggests, voltage drop typically means the drop from the initial transmission. If the voltage drops, your system won’t receive the required power and may not function well. To reduce voltage drop, I recommend a correct-sized wire, mostly a bigger wire gauge, to reduce electrical resistance.
Distance
You should know that voltage drops with distance due to resistance. The wire gauge we discussed above applies when the distance is below 100 meters.
However, if it’s longer than this, you should use the next bigger gauge. Additionally, consider copper instead of aluminum because it’s heat resistant and has better conductivity, reducing current drop.
Conduit
You must also consider the conduits you should use for your wires. Remember that this is high-voltage wiring, so the conduit must meet high-quality standards. For example, it must have the right size and insulator per the NEC regulations.
What Are the Effects of Using Oversized Wire for Your 200 Amp?
While using an oversized wire may not affect performance, it’s unnecessary and expensive. In addition, such wires are bulky, hard to install, and may not fit standard connectors. Therefore, I would advise you to use the recommended size for any amperage for efficiency, functionality, and cost savings.
Do You Need to Derate Wire Ampacity for Bundled or Eclosed Wires In a 200-amp Service?
The straight answer is yes. You need to derate the wire ampacity to ensure the safety and effectiveness of bundles or enclosed wires. This precautionary measure reduces wire load and heat build-up.
Conclusion
You know the correct wire for your 200 amp service connection project. The only remaining thing is to consult local electrical safety guidelines before buying any wire.
