There are several extension cords available in the market. When taking a trip to an electrical shop, the number of choices available may overwhelm you, which is why it is important to have even the most basic idea about extension cords. Before diving in further, you may also want to read about 20, 30, 40, 50 & 60 amp wires and 70, 80, 100, 125, 150, 200, 400, 600 amp wires. Here’s the table that includes the various extension cords we recommend, including the power they’re capable of carrying, as per their NEC ratings.
Aside from a variety of extension cords amps, they also come in a variety of lengths. Some of the most common available lengths that you can readily purchase are 10 feet, 15 feet, 20 feet, 50 feet, and 100 feet. Depending on your needs, you can easily pick the one closest to your requirements. It is tempting to pick the longest length as it may seem to be the most flexible, but that is not always the safest choice. A study by the United States Consumer Product Safety Commission highlights that extension cords are among the leading causes of fire accidents in the United States. The main reason for these accidents to happen is incorrect wire length and gauge size.
With these in mind, it is important to do some research before deciding which extension cord to purchase. Consumers should have the most basic knowledge behind these cords. In this article, we will be diving deep into the things you need to know about extension cords, specifically those that can support 20, 25, 50, 100, 150, and 200 feet. Each section below has its label, so you can quickly search through the article using your browser’s search functionality.
What to look for
There are several things to consider when looking for an extension cord. However, the top three things you should look into are the following.
Usage and Environment
What type of environment will you be using the extension cord? The outer layer of any wire protects from cold, moisture, or extreme heat. For outdoor extension cords, be sure to select one that has a thick outer layer. Indoor extension cords, on the other hand, do not need a thick outer layer. Perhaps you’re looking to power your TIG welder or MIG welder.
To determine the designation of your cord, look into the reference guide below.
- S – Flexible cord allows for use in almost anything.
- W – The cord is for outdoor use.
- J – The cord has a standard 300 V insulation. Otherwise, it has a thicker 600 V insulation.
- O – The cord is oil-resistant.
- P – It has a parallel wire construction, which you can use for household extension cords.
- T – The cover uses vinyl thermoplastic.
- E – The cover uses thermoplastic elastomer rubber (TPE).
- FT2 – The product is fire-resistant.
- CL2 – You can use the wire for in-wall construction.
The most common plug types you can find in an extension cord are the two-prong and three-prong. Depending on your type of application, there may be special requirements, such as a specialty plug to support high amperage devices.
It is important to choose an extension cord that can safely handle the power requirements of the devices you are connecting. Be aware of the amperage rating of your tools. When picking an extension cord, be sure it can support the devices you plan to connect. Otherwise, you may compromise your safety.
You can commonly use a three-foot length indoors. You can use a three-foot extension cord on a laptop with a nearby outlet.
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If you are on a desk or couch and need easy access to an outlet, you can use a six-foot extension cord. You can plug in some of your portable devices, such as a mobile phone or tablet, you comfortably charge it while using it.
You can use the 10-foot extension cord option for your air conditioner. Most ACs have a huge plug, making it difficult to attach to a socket under certain circumstances. Using a heavy-duty 10-foot extension cord can quickly address this issue.
The 20-foot extension cord option is great when you might need to extend your electrical capabilities within a single room. Perhaps you have an outlet in one part of the room, but you would like to also put up a lamp on the other side, where there’s no outlet. You can also use a 20-foot wire for other home needs. When using an electric cooking range, we recommend you pair this extension cord with a NEMA 14-50.
You can use a 25-foot extension cord outdoor, such as in a 50 amps RV. There are several AWG wires you can choose from. Some of the common ones for heavy-duty use are the 10-gauge wire and 12-gauge wire. If this length is unavailable, the next closest alternative is the 30-foot length.
When planning to use some appliances outdoors, the 50-foot extension cord option is a great way to extend an outlet’s reach. You can use a 10-gauge, 12-gauge / 12/3 wire, or 14-gauge wire for this application. Be sure you are using a heavy-duty extension cord to ensure it can safely handle the load. Some 50-foot models are retractable, so you can easily roll up the capable after use, convenient if you’re using it for a leaf mulcher outside.
However, if you plan to use 50 amps, you need at least an 8-gauge copper wire at an ambient temperature rating of 167°F or a 6-gauge aluminum wire at an ambient temperature rating of 167°F.
If the 50-foot option is too short, you may want to give the 100-foot extension cord length a try for your outdoor needs. In most cases, you may need a heavy-duty retractable extension cord so you can easily roll the cable.
Some of the common AWG wires you can safely use with a 100-foot length are the 10-gauge, 12-gauge, and 14-gauge. Sometimes, it may read as 10/3, 12/3, or 14/3 extension cord. The 10/3 extension cord can safely carry a maximum of 40 amps. It can handle anything below it, such as 20 amps or a 30 amp RV. On the other hand, a load of 50 amps is no longer safe. If you think 100 feet is too long and 50 feet is too short, there is a 75-foot option available.
A 150-foot extension cord is where it starts to become very long. With that said, you need a high amperage capacity to support the devices and appliances you will plug. Similar to 100 feet, it is best to purchase a retractable one, so you can easily roll up the wire. Most people use the 150-foot option for outdoors, such as using it to power up lights in the middle of your backyard.
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If you are looking for the longest length that is readily available in most electrical stores, the 200-foot extension cord option is the way to go. Ideally, you will need to use it outdoors. You can use it to supply power to your power tools, such as circular saw, grinder, and the like. When using these tools, you need a lengthy extension cord. We think the 200-foot option is a great choice.
Outdoor extension cords are those that you can use outside the house. Some might think you can only use an extension cord indoors, but recent advancements in technology made it possible to use extension cords outdoor. An extension cord that you can use outdoors has the letter “W” on the packaging or in the cord’s sleeve. If this information is not available, do not worry as there are other ways to determine.
The main difference between an indoor and outdoor extension cord is the insulating layer. Outdoor extension cords typically use a bright orange vinyl, rubber, or plastic that keeps moisture and other external elements away from the conductive part. The conductive part of the extension cord needs to be safe from any external elements. Exposure to these elements will lead to danger.
It is important to have a three-prong plug for your outdoor extension cord. The third prong serves as a grounding wire, which significantly reduces the risk of electrical shocks. A good number of the indoor type do not have a third prong, but some do. If these still confuse you, you may want to check on the extension’s amperage rating. Outdoor extension cords have a significantly higher amperage rating than indoor extension cords.
Now that we have discussed how to determine an outdoor extension cord, it is time to know some of the safety tips revolving around it. Whether it is indoor or outdoor, you need to store your extension cords properly. Unplug everything and carefully roll the extension cord back to its original package. Check for any cuts or wounds in the cord. If you see any, dispose of it right away. When storing an extension cord, be sure to keep it away from areas that accumulate moisture.
When taking an extension cord out of storage, be sure to inspect for any cracks or wounds before using it. The outer part of a wire cracks when it gets in contact with too much heat. If you notice any problems, do not use the extension cord at any cost. Brightly colored extension cords are also advisable, so you can easily locate them and prevent people from tripping.
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Extension cords come in different duties, such as light-duty, medium-duty, and heavy-duty. If your requirements need you to draw 10 to 15 amps of power, you need to use a heavy-duty extension cord. What makes it different from the other duties is that it is always grounded. It comes with a third wire and plug prong, which serves as the grounding. It also has plugs with three slots for accepting grounded appliances and devices.
Power tools and heating appliances are a few of the heavy-duty appliances that draw up to 15 amps of power. Most of these wires use a NEMA 6-20 plug type. For the AWG wire size, the following should serve as a guide.
- 14-gauge wire for a cord length of up to 25 feet
- 12-gauge wire for a cord length of up to 50 feet
- 10-gauge wire for a cord length of up to 100 feet
Although the information here is generally accurate, you have to check the manufacturer’s manual regarding the use of these extension cords. If you are looking for a portable welding machine, we have a curated list of some of the best engine-driven welders available in the market.
8, 10, 12, or 14 gauge
The 8, 10, 12, and 14 gauge sizes are a few of the most common sizes available in the market. Below entails the amperage capacity of each gauge size.
An 8-gauge aluminum wire can safely carry up to 40 amps at 167°F or 45 amps at 194°F. On the other hand, an 8-gauge copper wire can safely carry up to 40 amps at 140°F, 50 amps at 167°F, and 55 amps at 194°F.
A 10-gauge aluminum wire can safely carry up to 30 amps at 167°F or 30 amps at 194°F. On the other hand, a 10-gauge copper wire can safely carry up to 30 amps at 140°F, 35 amps at 167°F, and 40 amps at 194°F.
A 12-gauge aluminum wire can safely carry up to 20 amps at 167°F or 25 amps at 194°F. On the other hand, a 12-gauge copper wire can safely carry up to 25 amps at 140°F, 25 amps at 167°F, and 30 amps at 194°F.
There is no aluminum option for the 14-gauge wire. However, a 14-gauge copper wire can safely carry up to 20 amps at 140°F, 20 amps at 167°F, and 25 amps at 194°F.
30 & 50 amp RV Extension Cord
RV extension cords are useful because it allows for flexibility. It lets you connect to the right power source without having to sacrifice much. These extension cords classify under heavy-duty use, so be sure to select a cord that can safely handle the heavy-duty load. RV extension cords usually rate at 30 amps or 50 amps, depending on the usage.