200 amp service is common in most standard houses. Choosing wires for this service is important so that everything remains safe. Ground wire protects you from severe fire hazards and shocks. Today, we will discuss the ground wire size for the 200 amp service.
Generally, the ground wire size for a 200 amp service ranges from 2 AWG to 8 AWG. The best one is 2 AWG for copper wire and 4 AWG for aluminum or copper-clad aluminum wire. It is recommended to use them with 1.5-2.5 inches schedule 40 or 80 PVC conduit for underground service.
It may differ depending on the materials, permission rules, codes, etc. This guide will give you detailed information about the ground wire size of 200 amp services and what essential things should be considered.
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This post includes some affiliate links.What is the wire size for the 200 amp service?
The term amp is known to a lot of people. Amp is a base unit that measures the volume of electricity.
If your house has a 50 amp service, the service will give you only 50 amp of electricity.
Many people have decided to upgrade to a higher electricity service due to the introduction of several electrical appliances.
So, most standard houses have 200 amp service.
Besides the ground wire, there are many other things to consider while upgrading the electrical service.
Both the hot and neutral wires for 200 amp service have to be around 2/0 AWG if you use copper wires.
If you use copper-clad aluminum, the wire size must be 4/0 AWG.
Whatever size you choose, the measurement for the hot and neutral wires will remain the same.
What size of grounding wire is needed for 200 amp service?
Grounding wire size for 200 amp service ranges from 2 AWG to 8 AWG.
Besides, the sizes may differ depending on the materials, like:
| Copper | Aluminum |
|---|---|
| 8 AWG | 6 AWG |
| 4 AWG | 2 AWG |
| 6 AWG | 4 AWG |
| 2 AWG | 4 AWG |
Ground wires support us by creating an alternate path for the current to flow when any short circuit occurs.
The ground wires take up the excess electricity from the power surges and help them flow through the ground rods.
The copper wire for the grounding has to be at least 2 AWG in diameter to give the maximum voltage.
Aluminum has low conductivity levels and is more vulnerable to heat and corrosion.
So, they must be a higher gauge to maintain a proper balance.
The best ground wire size for 200 amp service is 4 AWG copper wire or a 2 AWG copper-clad aluminum wire.
According to Article 250 of the 2020 NEC (National Electric Code), 4 AWG copper and 2 AWG aluminum is the minimum ground wire size in 200 amp.
The wire size will change depending on your location, fault current, and run length.
Find out NEC guidelines and the code of your living area.
All regions have their grounding chart. Follow it and then decide the size of the ground wire.
If you are building a new house or upgrading your power service, do not forget to include the ground wire with the hot and neutral wires.
Grounding has now been legalized. So, not including the ground wire will be punishable by the law in certain areas.
What factors should be considered before buying a grounding wire?
Before you buy the wires, you need to consider a few things:
The wire sizes
You will require three wires – hot or live, neutral, and ground.
The hot and neutral wires need to be the same size because they will carry the same amount of currents.
On the contrary, the ground wire doesn’t have to be the same size as the hot or neutral.
Use big wires
The ground wires can be larger than the other wires for a 200 amp service.
If you bring or use a large ground wire, there won’t be a problem.
Though expensive, a big wire will play the same role as the smaller gauges.
However, the correct size of gauges has more resistance.
But it should not be too small. That won’t be able to hold enough current and start a fire.
What kind of wire should I buy for a 200 amp service?
Using the best material is vital if you want the best for your house.
Read on to know the best kind of wire for 200 amp service:
Copper
Copper is considered the best and most famous type of wire.
It has the best electrical conductivity.
With a lower gauge, copper can carry more currents using less insulation.
Copper also has more resistance to heat and corrosion compared to other materials.
The copper wires are soft and thin so that they can be shaped and worked with easily without any issues.
Here are some brief reasons behind using copper:
- Copper can be used for longer distances due to its strong conductivity and heat resistance.
- Copper is more heat-resistant because it doesn’t expand or contract much and remains tight.
- The wires are thinner and thus, can be bent for easy working without any breakages.
- Copper has better electrical loads with less insulation and smaller gauges.
- The wire is corrosion-resistant because it has a metal called Patina, which doesn’t have much effect on conductivity.
Aluminum or copper-clad aluminum
Though copper is considered the best, aluminum is also a good option.
Aluminum is cheaper than copper.
Besides, aluminum wires are flexible and lightweight, making them easier to work with.
Due to their flexibility, you can work with aluminum wires faster.
If you want to work with something affordable, you can try aluminum.
But if you can afford copper and want the best, go for copper.
The type of wire and gauge will differ if you use ground wires for longer distances.
A longer wire requires more resistance, increasing the voltage drop.
To increase the resistance, you must increase the gauge.
A long ground wire will require a better gauge.
It is where copper-clad aluminum will help. But, the wire is more expensive than the aluminum wires.
If you have that budget, you can go for this option.
Many people use copper-clad aluminum because, despite being aluminum, it carries better electricity than aluminum.
Thus, it is not ideal enough for houses with large loads.
Here are some reasons behind using aluminum or copper-clad aluminum:
- Since aluminum is lightweight, they are very worked with at a faster rate, saving time.
- Aluminum is cheaper to use. But, copper-clad is more expensive than aluminum.
- The wire is larger than copper and still easy to use due to its lightweight.
- The wires are made with smaller solid aluminum strands instead of single solid waste. So, it is ideal for residential settings.
Factors affecting the type of wire
Depending on certain factors, the wire material will change.
Considering those factors, you can understand and select the best wire for your house.
Here are the factors:
Longer lengths
The type of wire differs depending on how many feet you need the ground wiring.
Though both wires are meant for 200 amp services, copper would be the best option for longer lengths.
Copper has longer lengths, conducts better, and doesn’t contract like aluminum.
Though aluminum can be used for longer lengths, it can interfere with the flexible electricity flow because it contracts.
If you still want to use aluminum, opt for the copper-clad and use some copper fittings at the end of the wire.
Wire distance
Copper is commonly used for a longer distance than aluminum.
However, both are made for 200 amps.
Sometimes, the voltage drop determines the type of wire used for grounding.
The maximum drop is 3%.
For example:
| Distance (3% voltage drop) | Copper | Aluminum |
|---|---|---|
| 50 feet | #2/0 | #4/0 |
| 100 feet | #3/0 | 300 kcmil |
The measurements may differ depending on the phases and wire voltage.
How to ground a 200 amp service?
Let’s see how to ground a 200 amp service:
Stack a grounding rod
A grounding rod connects a grounding system to the earth.
This rod is also made of copper for good electrical conductivity.
Generally, the grounding rods are around 8-10 feet long.
To reach greater depths, the contractors recommend placing the rods in moist areas.
But, if your soil is flexible enough to work with, you can also put them on dry grounds.
Use the grounding wire to connect the ground connection with the rod.
Connect the neutral wire with the larger lug in the neutral bus bar before connecting the ground bushing with the ground bar.
Run the ground wire from the ground bus to various locations.
Though you can do this with a little experience, you can leave it to the professionals.
To do it on your own, you will require permission for things related to 200 amp services.
Wire size chart for 200 amp service
This size chart will help you understand which wire size is ideal depending on the voltage, distance, and material.
Single phase
| Distance | Wire size (copper) | Wire size (aluminum) |
|---|---|---|
| 50 ft | 3/0 AWG | 250 MCM |
| 75 ft | 3/0 AWG | 250 MCM |
| 100 ft | 3/0 AWG | 250 MCM |
| 200 ft | 250 MCM | 400 MCM |
| 250 ft | 350 MCM | 500 MCM |
| 300 ft | 400 MCM | 600 MCM |
| Distance | Wire size (copper) | Wire size (aluminum) |
|---|---|---|
| 50 ft | 3/0 AWG | 250 MCM |
| 75 ft | 3/0 AWG | 250 MCM |
| 100 ft | 3/0 AWG | 250 MCM |
| 200 ft | 3/0 AWG | 250 MCM |
| 250 ft | 3/0 AWG | 250 MCM |
| 300 ft | 4/0 AWG | 300 MCM |
| Distance | Wire size (copper) | Wire size (aluminum) |
|---|---|---|
| 50 ft | 3/0 AWG | 250 MCM |
| 75 ft | 3/0 AWG | 250 MCM |
| 100 ft | 3/0 AWG | 250 MCM |
| 200 ft | 3/0 AWG | 250 MCM |
| 250 ft | 3/0 AWG | 250 MCM |
| 300 ft | 3/0 AWG | 250 MCM |
3-phase
| Distance | Wire size (copper) | Wire size (aluminum) |
|---|---|---|
| 50 ft | 3/0 AWG | 250 MCM |
| 75 ft | 3/0 AWG | 250 MCM |
| 100 ft | 3/0 AWG | 250 MCM |
| 200 ft | 250 MCM | 350 MCM |
| 250 ft | 300 MCM | 500 MCM |
| 300 ft | 350 MCM | 600 MCM |
| Distance | Wire size (copper) | Wire size (aluminum) |
|---|---|---|
| 50 ft | 3/0 AWG | 250 MCM |
| 75 ft | 3/0 AWG | 250 MCM |
| 100 ft | 3/0 AWG | 250 MCM |
| 200 ft | 3/0 AWG | 250 MCM |
| 250 ft | 3/0 AWG | 250 MCM |
| 300 ft | 3/0 AWG | 250 MCM |
| Distance | Wire size (copper) | Wire size (aluminum) |
|---|---|---|
| 50 ft | 3/0 AWG | 250 MCM |
| 75 ft | 3/0 AWG | 250 MCM |
| 100 ft | 3/0 AWG | 250 MCM |
| 200 ft | 3/0 AWG | 250 MCM |
| 250 ft | 3/0 AWG | 250 MCM |
| 300 ft | 3/0 AWG | 250 MCM |
Note: While calculating the wire size at different voltages, copper size, and phases, I have considered a 3% of voltage drop.
Final thoughts
Understanding the sizes of wires is very important.
There are many sizes of wires for a 200 amp service. The best ground wire for 200 amp service is 2 AWG copper or 4 AWG aluminum, or copper-clad aluminum.
The range of ground wire size remains between 2 AWG and 8 AWG. The size will differ depending on the location codes, the materials, voltages, voltage drops, etc.
You may use both copper and aluminum; copper is the best choice. But since it is expensive, you can go for aluminum.
For a better aluminum version, spend a little more money and get hold of copper-clad aluminum.
FAQs
Can I run a 200 amp sub panel off the 200 amp main panel?
Yes, you can do so, but a 400 amp panel is better.
It will prevent the tripping of the breaker and wires from burning.
Can I overload a 200 amp panel?
A 200 amp can handle around 48k watts.
Besides, the panel gives information about how much electricity the panel will handle and how much has been loaded.
Excessive overload will damage the breaker box and the wires and create a fire hazard.
What is the minimum size for a service entrance conductor?
The grounding conductor for a 200 amp service must be at least 4 inches in diameter and 6 feet in length.
The copper wire should be at least 4-6 inches AWG.
Data Source: National Electrical Code
