How many amps can 18 gauge wire (breakdown with photos)
Content
- How many amps can 18 AWG handle?
- How many amps can an 18 gauge wire handle at 12 volts?
- How many amps can an 18 gauge wire handle at 24 volts?
- How many amps can an 18 gauge wire handle at 120 volts?
- How many amps can an 18 gauge wire handle at 240 volts?
- Using 18 gauge wire
- What is 18 gauge wire rated for?
- Does the material (aluminum/copper) change the amperage?
- Benefits of understanding 18 gauge wire amps
- F.A.Q.
- Summing up
Most people don't understand the relationship between wire gauge and capacitance. One might think that 18-gauge wires can be used in any circuit, but this is not the case. When the voltage changes, the maximum current value for that particular wire changes. Similarly, we cannot ignore the length of the wire and its influence. I have experienced this first hand on many electrical projects. So today I'll be focusing on the disassembly and discussion of how many amps 18 gauge wire can handle.
Typically, 18 gauge wire can handle 14 amps at 90°C. This is the standard level followed by most electricians. However, depending on the distance and voltage, the above current value may change.
How many amps can 18 AWG handle?
AWG stands for American Wire Gauge. This is the standard method for measuring wire gauge in North America.
18 AWG copper wire withstands 14 amps at 90°C. Typically 18 AWG has a wire diameter of 1.024 mm2 and a cross-sectional area of 0.823 mm2.
The amplitude depends on various factors such as non-reactivity, voltage rating, flexibility, density and flammability. However, temperature can be called the most significant factor. When the temperature is high, the rated power increases.
That's why most professionals list the specific temperature with the wire size. In the screenshot above, you can find different sizes of wires that are suitable for certain temperatures and distances.
How many amps can an 18 gauge wire handle at 12 volts?
As I mentioned earlier, amperage varies with voltage and wire length. So when you apply 12V, the current varies from 0.25A to 10A depending on the distance. Voltage drop is the main reason for this change.
Voltage drop
Whenever the wire resistance increases, the voltage drop increases accordingly. If you're having a hard time understanding the concept above, this explanation might help.
The resistance depends on the cross-sectional area and the length of the wire. Follow the equation below.
Here R is the resistance. ρ is the resistivity (constant value). A is the cross-sectional area of the wire and L is the length of the wire.
Thus, as the length of the 18-wire gauge increases, the resistance increases accordingly.
According to Ohm's law,
V is voltage, I is current, and R is resistance.
Therefore, at a higher resistance, the voltage drop increases.
Permissible voltage drop
The allowable voltage drop should be less than 3% for lighting and 5% for other electrical appliances.
Given the voltage drop, here are some examples for 12V and 18 gauge copper wires.
Example 1
As you can see, if the current is 5 amps, you can run 18 gauge wire 5 feet.
Example 2
As you can see, if the current is 10 amps, you must run 18 gauge wire less than 3 feet apart.
Follow this link for a voltage drop calculator.
How many amps can an 18 gauge wire handle at 24 volts?
When the voltage is 24 volts, 18 gauge wire can handle current ranging from 10 VA to 50 VA. As in the examples above, these values have different distances.
Example 1
As you can see, if the current is 5 amps, you can run 18 gauge wire 10 feet.
Example 2
As you can see, if the current is 10 amps, you need to run 18 gauge wire 5 feet.
How many amps can an 18 gauge wire handle at 120 volts?
At 120 volts, 18 gauge wire can handle 14 amps (1680 watts). You can run 18 gauge wire 19 feet.
Keep in mind: Here we keep the allowable voltage drop below 3%.
How many amps can an 18 gauge wire handle at 240 volts?
At 240 volts, 18 gauge wire can handle 14 amps (3360 watts). You can run 18 gauge wire up to 38 feet.
Using 18 gauge wire
Most often, 18 gauge wires can be located in 10A lamp cords. In addition, you can find 18 gauge wires in the following applications.
- 18 gauge wire is an excellent option for car batteries and other automotive applications. For example, most speaker wires are 12 to 18 gauge.
- Some people use 18 gauge wire for extension cords. For example, in power tools such as drills and grinders, these 18 gauge wires are common.
What is 18 gauge wire rated for?
18 AWG wire is rated for low voltage lighting.
Does the material (aluminum/copper) change the amperage?
Yes, the type of material directly affects the amperage. Aluminum and copper are the most common materials used to manufacture these AWG wires. Before we dive into how current varies with material, here are some of the unique features of these conductors.
Copper
Among the two metals mentioned above, most manufacturers use copper for the production of wires. You can find copper wires in modern electrical distribution equipment and electronics. There are many reasons for such popularity. Here are some of them.
higher conductivity
One of the significant reasons for such popularity is conductivity. Copper has the highest electrical conductivity among non-precious metals. This means that copper is more conductive than aluminum.
Lower thermal expansion
In addition, the lower coefficient of thermal expansion is also an advantage of using copper. Because of this, copper does not easily change with temperature changes.
Opportunity to get green patina
Green patina is a chemical that forms naturally on bronze and copper. This chemical is a mixture of sulfides, copper chloride, carbonates and sulfates. Due to the green patina layer, copper has a higher corrosion resistance.
Tip: The green patina does not affect the characteristics of the copper wire.
Aluminum
Aluminum is a less popular metal compared to copper strands. However, aluminum does have some unique features that can be quite beneficial. Here are some of them.
Less weight
Despite the fact that aluminum has 61 percent less conductivity than copper, aluminum is equal to 30 percent of the weight of copper. Because of this, aluminum wires are easy to handle.
Inexpensive
Compared to copper, aluminum is much cheaper. If you are looking for a low budget electrical wiring project, aluminum should be your choice.
Keep in mind: Aluminum reacts with water and releases hydrogen gas. This is a major problem among manufacturers. They cannot use aluminum wires for tasks such as laying submarine cables. (1)
What about current strength?
For example, if you are using 8 gauge copper wire for a given task, you will need 6 gauge aluminum wire for the same task. Remember that with higher gauge numbers, the thickness of the wire decreases. So, you will need thicker aluminum wire.
Benefits of understanding 18 gauge wire amps
Knowing the amperage ratings for 18 gauge wire will help you select the right electronics and applications. With a smaller thickness, the resistance of the wire increases due to the smaller cross-sectional area. This means that the wires will get hot and eventually melt. Or sometimes it can affect your electronics. Therefore, connecting with the correct gauge of wire is critical. Do not use 18 gauge wire on a circuit that exceeds 14 amps. (2)
F.A.Q.
Does distance affect amps?
Yes. As the distance increases, the value of the amplifier decreases due to the higher resistance. This is why you must run the wires at an acceptable voltage level.
Maximum current for 18 AWG wire?
Typically, 18 AWG wire can handle up to 16A. But the recommended level is 14A. So, keep the amplifier value in a safe zone.
What is the ampere rating for 18 gauge stranded wire?
The average wire rating of 18 gauge is 14A. However, solid wires are capable of carrying more current than stranded wires. Some professionals may limit 18 gauge stranded wire to 7A.
What is the ampere rating for 18 gauge automotive wire?
18 gauge automotive wires are unique. These wires can work from 3A to 15A. When it comes to distance, you will be able to cover from 2.4 feet to 12.2 feet.
Summing up
Undeniably, 18 gauge wire is an excellent choice for low voltage installations. Especially if you are using 10 amp bulbs, 18 gauge wire is ideal for these bulbs.
However, be sure to do your homework before making your final decision. Check the level of voltage drop depending on the distance. Also check the wire type; hard or twisted. Do not use stranded wire instead of solid wire. Such a stupid mistake can damage your electronics or melt wires.
Take a look at some of our articles below.
- How many watts can 16 gauge speaker wire handle?
- What is the wire size for 20 amps 220v
- Where to find thick copper wire for scrap
Recommendations
(1) submarine cables - https://www.business-standard.com/podcast/current-affairs/what-are-submarine-cables-122031700046_1.html
(2) electronics – https://www.britannica.com/technology/electronics
Video links
