How Well Do You Know Portable Extension Cords? Here Are 7 Critical Insights

Many people have lost count of the number of times they checked into an electrical store, carefully sampled the available accessories, but still walked out with the wrong product. That’s partly due to the striking resemblance between various electrical attachments.  

Take a case of power strips and extension cords, for instance. Despite their (sometimes unnoticeable) differences in cable lengths, these accessories are nearly identical to many shoppers.  

Portable extension cords are among the most common products in a reputable electrical outlet. But what are they, and when might they be applicable? Well, this blog shall attempt to answer that question.  

Read below as we uncover portable extension cables and the seven essential things to know about them. 

Unveiling Portable Extension Cords 

Portable extension cords are electrical cables designed with multiple conductors, typically used for temporary power connections that require a bit of flexibility. They’re regionally known as flexible cords, portable cordage, or extension cords.  

Portable extension cords are an invaluable investment for anyone seeking a short-term power supply in outdoor or off-site environments. Homeowners can rely on these cables to extend the reach of electricity to their backyard lighting installations, lawnmowers, BBQ grills, and garage tools.  

Similarly, contractors may use flexible cords to power their property renovation tools or construction equipment. The application ultimately depends on the wire’s compatibility with the intended appliance.  

Like most electrical attachments, flexible cords have varied features and power-handling abilities. Selecting the right extension cord calls for due diligence and an in-depth understanding of the available options.  

The following section shall highlight the seven critical insights while buying and handling portable cordage.  

7 Critical Facts About Portable Extension Cords

1. Portable Extension Cords Are Distinct From Power Cables

Many people erroneously use the terms ‘portable extension cords’ and ‘power cables’ interchangeably. But while both accessories are meant to supply electricity between different locations, they’re fundamentally distinct from each other.  

As already mentioned, portable cordage is a multi-conductor cable commonly utilized for short-term electrical connections. These wires are remarkably flexible, which is understandable considering that they’re meant to be moved across different locations.  

Standard portable extension cords have at least two bare copper conductors. However, the cables may vary considerably in their conductor stranding as well as jacket and insulation materials.  

Portable extension cords boast diverse applications, too. You can use them as home extension cords or to power industrial equipment.  

Like regular extension cords, portable cordage may be rated for the indoors or outdoors. Outdoor flexible cords may further bear different letter designations depending on the specific environmental hazards they can withstand - abrasion, extreme temperature, moisture/water, oil, chemicals, and ultraviolet (UV) rays.  

On the other hand, power cables are designed for permanent connections. These cords aren’t meant to be moved frequently and are usually installed as overhead wiring or direct burial applications.  

Unlike portable extension cords that almost always feature multiple conductors, many power cables have single conductors. The two sets of wires also vary considerably in their ideal use cases.  

Portable power cables are more versatile and can be deployed in both home and industrial settings. That’s in contrast to power cables, which are typically used in commercial and industrial centers. 

Common appliances that utilize power cables include drilling rigs, mining equipment, shipyards, and locomotives. The wires may also be used for lower-voltage applications like thermostat controls, signal systems, and AC installations.  

2. Portable Extension Cords Have Different Gauge Ratings

Gauge is a fundamental distinguishing factor between different portable extension cords. The term refers to the diameter or thickness of the conductors in electrical cables and is commonly denoted by the initial AWG (American Wire Gauge).  

Portable extension cords come in different gauge ratings, from 2 AWG to 20 AWG or over. However, the 14 and 12 gauge extension cord are the most popular options.  

Smaller numbers correspond with thicker wires. For instance, an 8-gauge flexible cord has a larger diameter of 0.1285 inches compared to 0.0641 inches for an 18-gauge wire.  

It’s also important to point out that thicker conductors have superior conductance than their thinner counterparts. So, when you compare the 14 gauge vs. 12 gauge portable extension cords, you’ll realize that 12 gauge cables handle current much better.  

For power-hungry connections, it’s best to use a portable extension cord rated 12 AWG or lower. 14-gauge portable cordage is ideal for medium-duty appliances, while 16 AWG or higher would suit lighter-duty applications.  

The table below matches various appliances with the correct portable extension cord gauge ratings; 

3. Gauge and Ampacity Are Correlated

Now that we’ve gotten the portable extension cords’ wire gauge explained, you may be wondering if conductor thickness is the only essential factor when shopping for these attachments. Well, not quite.  

Portable cordage’s gauge ratings are correlated with their ampacity.  

Ampacity is an electrical term for the amount of current that flows through an electrical circuit in unit time. It’s measured in amperes or amperage (amp). Ampacity is an important factor when determining the suitability of a flexible cord for the intended application. 

Just like gauge ratings, amperage is inversely proportional to conductor diameters. That means higher-gauge portable cordage like 18 AWG has lower amperage than lower-gauge cables like 8 AWG.  

While shopping for portable extension cords, it’s essential to consider their AWG and amp ratings. However, since not all manufacturers will indicate both specifications on their products’ labels, you’ll need to understand the correlation between the two metrics before you hit the electrical stores.  

For instance, 16-gauge portable extension cords typically draw 13 amps, while 14 AWG wires can draw up to 15 amps.  

Below are other common portable cordage gauge ratings and their corresponding current draws; 

18 AWG – 10 amps 

20 AWG – 20 amps

4. Portable Extension Cords Come In Different Lengths

Length is yet another top consideration when scouting for the best portable extension cords.  

Fortunately, flexible cords come in diverse lengths. Some are as short as 15 feet, while others can be up to 200 feet long.  

While shopping for flexible cords based on length, you’ll need to estimate the distance between the nearest electrical outlet or receptacle and the appliance you need to connect the wire to. Then, pick a cable that’s 2 - 5 feet longer.  

The heavy duty extension cord 100 ft would be excellent for applications like construction sites. But if you require a cable to power your patio lights, then a smaller option like 20 feet would suit you better.  

Investing in a bulk extension cord wire helps to avoid daisy-chaining. Daisy-chaining occurs when you connect multiple flexible cords in a series or sequence, ostensibly to extend the reach of electricity to appliances. However, this practice is linked to current overload. 

Similarly, experts discourage buying a very long portable extension cord.  

Voltage drop is the biggest issue with longer cables. Volt (V) measures the force or pressure by which electrons flow through an electric circuit. Like gauge and ampacity, volt ratings are key when trying to match portable extension cords with the right appliances.  

Excessively long flexible cords may also lead to entanglement. If not properly organized, tangling can increase tripping hazards and cause the conductor materials to twist and break. 

5. Portable Extension Cords’ Length Impact Their Voltage and Resistance

Most portable cordage has a voltage rating of 120 V. Every additional foot on a flexible cord increases resistance. This results in a voltage drop, significantly affecting the cable’s power-handling properties.  

For perspective, a 50-foot portable extension cord may work efficiently if rated 12 AWG and draws 15 amps. But if the length doubles, the cable will lose significant voltage even if the gauge and amp ratings remain constant.  

Fortunately, you can strike a balance between a portable extension cord’s length and voltage rating by choosing a cable with proper conductor thickness. Start by calculating your average working radius, then pick an outdoor extension cord designed for those measurements.  

For 0 - 25 feet, you may use up to a 16 AWG flexible cord. But for a 25 - 50 working radius, a 14- or 12-gauge wire would be ideal. The actual gauge would depend on your power demands.  

For 50 - 100 feet, it’s safer to use a 12 AWG portable extension cord. You might even opt for a 10 AWG cable for more power-demanding applications.  

Longer portable cordage measuring over 100 feet must have thicker conductors of at least 10 AWG.  

If you’re doubtful about the best wire voltage to buy, insist on a heavy duty extension cord even if the appliance is less power-intensive. Using a heavy-duty wire with lighter-duty appliances is safer than vice versa.  

6. Portable Extension Cords Are Rated For Diverse Use   Environments 

Flexible cords vary significantly in their intended use environments. Cables rated for outdoor applications can withstand harsh conditions, from extreme temperatures to moisture ingress, UV damage, and even chemical abrasion.  

But how do you determine a portable extension cord’s suitability for diverse weather?  

Well, the trick is to look out for specific letter designations in the wire’s outer insulation.  

The initial ‘S’ in portable extension cords stands for “service” or “extra hard service, " which means the cable is rated 600 volts. But if the letter appears alongside another initial associated with voltage, i.e., ‘J,’ then it stands for “junior service” or “junior jacket.” Such cables are rated for 300 volts.  

T is another common designation you’ll find on portable extension cord insulations. It stands for tinsel cord (if it’s the first letter on the product’s label) or thermoplastic (if not the first letter in the code).  

Tinsel cord is an electrical wire renowned for its flexibility and resistance to metal fatigue compared to solid and stranded wire. It’s commonly found in smaller appliances like telephones, headphones, and handsets.  

However, tinsel wire has a lower current handling capacity despite its superior mechanical flexibility. So, it’s uncommon in many heavy-duty flexible cords.  

Thermoplastic cords have outer insulations and jackets made from thermoplastic elastomer (TPE). TPE can maintain flexibility within temperatures of – 40 to 220 degrees Fahrenheit. The material is also somewhat resistant to UV and chemical damage.  

Below are other essential codes to look out for in portable extension cords: 

H – Heat resistant 

O – Oil-resistant jacket (for one O) or oil-resistant jacket and insulation (for two OOs) 

W – Weather and water-resistant 

7. Portable Extension Cords Must Have Proper Safety Features

You’ve probably already figured out that portable extension cords are mostly used outdoors. However, these cables can be just as reliable for indoor applications. Regardless of the intended use environment, it is essential to ensure they come with proper safety features to guard against electrical hazards like shocks and explosions.  

First, insist on flexible cords designed with surge protectors and ground-fault circuit interrupters (GFCIs).  

A surge protector extension cord shuts down the power supply in case of unwanted current spikes. This can minimize costly appliance repairs caused by erratic current surges.  

On the other hand, a GFCI extension cord interrupts the power supply upon detecting an unintended current path. Such cables can be a lifesaver when working in damp or moist conditions.  

It’s also important to insist on flat-plug cords.  

True to its name, a flat plug extension cord has a flatter rather than a rounder plug. These cables can fit compactly into outlets and receptacles, allowing you to move appliances closer to the walls without risking damage to the plugs.  

A 10/3 extension cord is another option to consider when looking for safe extension cords. The number 10 denotes the gauge rating, while 3 stands for a 3-pronged plug. Three-pronged cables are safer than two-pronged wires due to the additional pin, which serves as a grounding wire.