What wire size for 30 amps 200 feet (tips and tricks)
Content
- Permissible voltage drop
- Recommended wire size for 30A, 200ft.
- Aluminum or copper?
- Voltage drop across 4 AWG copper wire
- Can I use 3 AWG wire for 30 amps at 200 feet?
- What is the maximum distance for a 30 amp circuit with 10 gauge wire?
- Poor results Using a smaller wire
- What wire size is best for 30 amps at 200 feet?
- Is it safe to use an extension cord from my house to the barn?
- Summing up
Whether you are running an extension or underground conduit, proper execution and selection of the correct wire size is a must. Wiring with incorrectly sized electrical wires can be disastrous. Sometimes this can lead to fire, damage to appliances and melted wires. So, with all that in mind, I plan to teach what size wire is needed for 30 amps at 200 feet.
In general, to run a 30 amp circuit at 200 feet, you'll need 4 AWG wire; it is the perfect choice for your electrical wiring project. If you are using 120V this will give you a 2.55% voltage drop. This voltage drop is below the recommended 3% voltage drop.
Permissible voltage drop
If you are using a low voltage installation and this connection is from a public distribution system, you will need to keep the voltage drop below 3% for lighting and below 5% for other purposes. Exceeding these values can lead to very harmful consequences. So remember to keep the voltage drop within the safe zone.
Recommended wire size for 30A, 200ft.
For any electrical wiring project, you must choose wires based on your long-term requirements. Thus, the type of wire material is critical. For example, when buying, you should choose from copper and aluminum wires.
If you choose copper, 4 AWG will be sufficient for a 30 foot 200 amp extension. On the other hand, 300 Kcmil aluminum wire will do the trick.
Keep in mind: Depending on the value of the amplifier, the wire size may change.
Aluminum or copper?
Both aluminum and copper are excellent conductors. But which one is more suitable for underground wiring project? (1)
It depends on many factors. So, here are a few facts that may help you make your decision.
Tensile strength
For any underground wire, higher tensile strength is critical. This ensures that the wire does not break easily. The tensile strength of copper is far superior to aluminum. Copper has 40% higher tensile strength than aluminum. This way you will be able to navigate the wires without any hesitation.
thermal expansion
Thermal expansion refers to the ability of a metal to expand when that particular metal is exposed to heat. Usually copper wires don't expand that much. Compared with aluminum, the thermal expansion value of copper is low.
Conductivity
If you are unfamiliar with conduction terms, here is a simple explanation. When heat or electric current passes through a material, it encounters some resistance from that particular material. Conductivity measures this resistance. In terms of electrical conductivity, copper is a much better choice than aluminum.
The above three facts are more than enough to decide which is better, aluminum or copper. Without a doubt, copper wires are the best option for underground wiring.
Tip: Silver wires are the best conductors. But, much more expensive than copper wires.
Voltage drop across 4 AWG copper wire
For 120 volts, 30 amps, and 200 feet of run, 4 AWG wire shows a voltage drop of 3.065 volts. As a percentage, this value is 2.55%. So the voltage drop is in the safe zone.
Tip: For 240V, the voltage drop is 1.28%.
Can I use 3 AWG wire for 30 amps at 200 feet?
Yes, you can use 3 AWG copper wire for 30 amps and 200 feet. But in terms of conductivity, 4 AWG wire is ideal. 3 AWG wire is thicker than 4 AWG wire. Therefore, a 3 AWG wire will create more resistance than a 4 AWG wire. This means less conductivity for 4 AWG wire. 3 AWG wire is the maximum diameter wire you can use for 30 amps at 200 feet.
What is the maximum distance for a 30 amp circuit with 10 gauge wire?
When we talk about a 200 foot extension cord, 10 AWG copper wire is one of the most controversial topics on the internet. Most people consider 10 AWG wire to be the minimum diameter for a 200 foot extension. This is true? Well, we'll find out below.
For 240V
When a 10 AWG wire travels 200 feet with 30 amps of current, there is a 5.14% voltage drop.
Maximum distance = 115 feet (assuming voltage drops below 3%).
For 120V
When a 10 AWG wire travels 200 feet with 30 amps of current, there is a 10.27% voltage drop.
Maximum distance = 57 feet (assuming voltage drops below 3%).
If you plan to use it with 30 amps, 10 gauge wire will work for less than 100 feet.. But this distance may vary depending on the initial stress. You will get a good idea after using the voltage drop calculator. This is the easiest way to find the corresponding distance.
Keep in mind: However, 10 AWG wire is the smallest wire that can be used for 30 amps. The only downside is that 10 AWG wire can't run 200 feet.
Bad results Using a smaller wire
The larger the wire, the more it can handle more current. However, these large wires can be quite expensive. Because of this, most people try to get the job done using a smaller wire. But they do not understand the consequences of such an act. For example, wires of smaller diameter fail under heavy loads. These failures will come in many forms. Below we are going to discuss these bad results.
fire outbreaks
A small faulty wire can cause an electrical fire. If things get out of control, the fire could destroy the entire building. Even circuit breakers may not be able to stop such an overload. In some cases, you may even experience an explosion. Thus, fires are the worst case scenario for using thin wires.
Melting
A heavy load can create a large amount of heat. This amount of heat may be too much for thin wires and capacitors. Eventually, the wires may melt. Not only that, this melting can affect the inside of the electronics. In most cases, these devices can be damaged beyond repair.
Damaged equipment
As mentioned in the previous section, melting can be one of the causes of damage to electrical appliances. But this is not the only reason. For example, all devices are powered by a 30-amp circuit. Thus, whenever devices do not receive enough electricity, they can completely burn out or partially fail.
Voltage drop
Whenever you run a distance of 200 feet, the voltage drop should be below 3% for lighting and 5% for other purposes. If the selected wire cannot support these settings, the entire circuit may be damaged. Thus, when you use a small wire, it may exceed the recommended voltage drop.
Export
Copper wires are able to withstand more wear and tear than aluminum wires. This does not mean that copper wires are invulnerable. Like aluminum wires, copper wires wear out if subjected to excessive stress.
What wire size is best for 30 amps at 200 feet?
While 10 AWG wire is a good choice for a 30 amp circuit, it cannot run 200 feet. On the other hand, 3 AWG wire is thicker. This means more resistance. So the obvious choice is 4 AWG copper wire.
Is it safe to use an extension cord from my house to the barn?
If you are planning to run a connection from your home to your barn, you have two options. You can stretch the extension cord, or you can bury the wire. Either way, you'll get the job done. But, from a safety point of view, it is best to bury the wire.
An extension cord is not a permanent outdoor wiring solution. For emergencies, this is a great method. But this is not the safest option. Here are some problems you may encounter when using an outdoor extension.
- The extension cord may be damaged.
- An unprotected extension cord can be hazardous to others.
- Connecting an extension cord to multiple devices is not a pleasant experience.
So, given the above factors, it is safe to bury the wire. To do this, you will need conduits and UF wires. UF means underground feeder. These wires are specially made for outdoor use.
Summing up
Laying 200 feet of electrical wire at 30 amps can be challenging depending on choice and execution. For example, you should choose from copper and aluminum. Then the correct wire size. Finally, the wiring method. Extension or hoses?
To be successful in an outdoor wiring project, you must make the right decisions. Otherwise, you will end up with blown or damaged appliances.
Take a look at some of our articles below.
- How to test a low voltage transformer
- How to test a circuit breaker with a multimeter
- Where to find thick copper wire for scrap
Recommendations
(1) aluminum – https://www.britannica.com/science/aluminum
(2) copper - https://www.britannica.com/science/copper
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