In order for the electrical system to work properly, you need to choose the right cable size. There are lots of different cable sizes, suitable for various applications, distances, etc. In this article, we’ll be exploring how to determine wire size and their applications. 

What is the Wire Gauge System?

The Wire Gauge System, commonly referred to as the American Wire Gauge (AWG), serves as a standardized method for categorizing electrical conductors like wires and cables. This system simplifies the identification of cable sizes by assigning numerical values, where lower numbers signify thicker wires, and higher numbers indicate thinner ones.

The American Wire Gauge is primarily used in North America. It is mainly used to specify the diameter of electrically conducting wire. Since wire thickness directly affects the electrical resistance, heat dissipation, and power transmission capabilities, the AWG offers reliable and consistent transmission of electric current. 

Wires with larger AWG gauge numbers, meaning thinner diameters, have higher resistance and can lead to overheating when managing higher currents. On the other hand, wires with smaller AWG gauge numbers, indicating larger diameters, are better equipped to handle these higher current loads without excessive heat generation. This property makes them ideal for applications involving power transmission and robust equipment. 

The terms 'WG' and 'gauge' are essentially synonymous. The wire gauge system, often referred to as AWG, involves assigning gauge numbers to wires to indicate their thickness. This numbering system is used to simplify wire selection, making it easier to choose wires that can handle specific current loads while maintaining efficient power transmission.

Why Is It Important To Get Your Cable Size Right?

The correct cable size means that your electrical systems will be safe and efficient. Let’s review some of the factors that contribute to importance of right cable size:

• Voltage Drop: Inadequate cable size can lead to excessive voltage drop over long distances, causing poor equipment performance, reduced efficiency, and even equipment failure. This can result in unreliable power delivery and increased energy consumption.
• Overheating: Undersized cables can't handle the current load, leading to increased resistance and subsequent heating. This can cause insulation damage, fire hazards, and overall reduced cable lifespan. Properly sized cables ensure optimal current-carrying capacity and minimize overheating risks.
• Circuit Protection: Incorrect cable sizes may affect circuit protection devices' responsiveness, such as circuit breakers and fuses. Inadequate protection compromises the system's ability to prevent short circuits and overcurrent situations, jeopardizing both equipment and safety.
• Economic Efficiency: Oversized cables are  more expensive and can waste resources. Undersized cables also require premature replacements due to wear and tear. Correct cable sizing ensures cost-effectiveness by balancing installation expenses and long-term performance.
• System Stability: Proper cable sizing maintains consistent power supply, prevents voltage fluctuations, and ensures equipment operates within designed parameters. Unstable power can disrupt sensitive electronics and lead to malfunctions.

Determining Wire Gauge: Step-by-Step Guide

Let’s learn how to determine wire gauge step-by-step. 

Step 1: Calculate Maximum Current 

Identify the maximum current your wire will carry. Consult device manuals or online resources for current values related to the devices you're connecting.

Step 2: Determine Allowable Voltage Drop 

Define the allowable voltage drop based on your application. Critical systems might have stricter requirements. Common values are 3% for critical systems and 5% for general use.

Step 3: Measure Wire Length 

Measure the distance between the power source and the load. Longer distances result in higher resistance and potential voltage drop issues.

Step 4: Calculate Maximum Allowable Resistance 

Apply Ohm's Law: divide the allowable voltage drop by the maximum current. This gives you the maximum allowable resistance for your setup.

Step 5: Find Wire Resistance 

Consult a wire resistance table to determine the wire's resistance per unit length. Make sure to consider the material of the wire.

Step 6: Determine Required Wire Gauge 

Divide the maximum allowable resistance by the wire's resistance per unit length. Refer to a wire gauge chart to find the appropriate wire gauge for your calculated value.

Step 7: Add a Safety Margin 

Choose a slightly larger wire gauge than your calculated value to account for potential variations in current loads and ensure safety against voltage drop and overheating.

Step 8: Check Local Regulations 

Always verify local electrical codes and regulations, as they may prescribe specific wire gauges for different applications.

By carefully following these steps, you canlearn how to tell what wire gauge is. This ensures not only safety but also efficient power distribution and optimal performance of your electrical system.

What Are the Most Popular Cable Sizes?

Several electrical cable sizes are widely used across various applications due to their versatility and compatibility. Some of the most popular cable sizes and their common applications include:

• 14 AWG: This size is commonly used for general household wiring, such as lighting circuits and outlets. It's also suitable for low-power appliances and devices.
• 12 AWG: Slightly thicker than 14 AWG, it's often used for heavier household appliances like kitchen appliances, heaters, and air conditioners.
• 10 AWG: This size is found in circuits that carry higher currents, like power tools and larger appliances. It's also used for wiring high-power lighting systems.
• 8 AWG: Used for circuits with even higher current demands, such as electric water heaters, electric vehicle charging stations, and larger industrial equipment.
• 6 AWG and 4 AWG: These sizes are employed for heavier industrial applications, such as heavy machinery, large motor connections, and power distribution in factories.
• 2 AWG and 1 AWG: These larger sizes find use in heavy-duty industrial settings, connecting large motors, generators, and industrial equipment that require substantial power transmission.

While these sizes are commonly utilized, the specific cable size chosen for any application should always be based on accurate calculations that consider current requirements, distance, voltage drop constraints, and safety regulations.

To determine the size of the wire you need for your electrical project, visit the wire size calculator.