Buying a generator can be one of the most beneficial investments you could ever make. Whether you’re preparing for a storm that’ll knock your city’s power out, need a portable source of energy to supply power to power tools far from the nearest available outlet, or need one to supply power for your RV, a generator can be your best friend in all situations.
However, when it comes to supplying power to your home with a standby generator or to your RV’s system with a portable model, using a generator isn’t as simple as pulling the recoil cord and plugging in your appliances. To supply your entire home safely with electricity produced from a generator, you’ll need the right type of generator cord.
What Is a Generator Power Cord?
A generator power cord is a means of transferring electricity from your generator to your home, RV, or directly to certain appliances and tools. The cord connects the generator to a transfer switch – manual or automatic – which, in a nutshell, draws in power from the generator and delivers it throughout the electrical system of your home or RV.
Installing a transfer switch should either be installed by a professional electrician or supervised by one to ensure proper installation.
The most common uses for having a generator power cord include supplying power to homes during blackouts, powering up heavy-duty machinery in remote areas such as in the middle of the forest to split logs, and supplying power to several devices during outdoor events. If you are familiar with any of these things, there’s very little reason not to invest in a good generator and the appropriate power cords.
Why Selecting the Right Generator Power Cord Matters
To get maximum effectiveness from your generator, you need the appropriate type of generator power cord. If you end up purchasing and using the wrong power cord, you’re potentially opening yourself, your home or RV, your appliances, or your generator to several risks, including costly damages. Although generators are designed to make life simpler, a lack of knowledge could end in a complete disaster.
Something that many people ask about is whether they can connect their generator directly to a wall outlet. This is called “backfeeding” electricity, and it’s something that you should avoid doing. This involves connecting a male-to-male cord from your generator to a wall outlet that can potentially lead to a catastrophic disaster. Never purchase, build, and/or use a male-to-male power cord.
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Types of Generator Power Cords and Plugs
Typically, we can split up the types of generator power cords based on their prongs and whether they can twist-lock into place. Below, we’ll describe the different plugs and receptacles commonly found in generators and what they are used for.
Duplex Outlet and Plug
The first type of generator cord that you’ll run across is a 15-amp, 2-prong plug and a 30- to 50-amp, 3-prong plug. This is a non-twist-lock design that works similarly to the wall outlets in your home. These outlets are normally used to supply power to your appliances by directly plugging them into the generator.
TT Plugs
These non-twist-lock plugs are designed specifically to connect a generator to an RV. This type of receptacle is commonly found in RV parks across the US. This plug cannot be used to direct power from the generator to your home’s electrical system so you’ll only need to pay attention to this type of plug when you hit the open road in your RV.
Twist-Lock Plug
There are multiple types of twist-lock plugs based on how many prongs they have (either 3 or 4) and how many amps and watts they can handle. We’ll discuss the details of how to find the right amperage and wattage deliveries in the next section of this article. It’s important to know that these receptacles can be used to directly supply energy from your generator to an RV, your home’s electrical system, and to heavy-duty machines like corded-electric log splitters.
Generator Power Cord Buying Guide
Now getting to the heart of the matter: how to pick the right generator power cord. Several factors come into play when choosing which type of cord to get. The following segment will describe each of these factors so you can make the right purchase decision.
Plug Type
First of all, you don’t want to purchase a generator power cord that isn’t compatible with your generator. The shapes of the plugs are intentionally designed to prevent any instances of electricity overloads. Be sure the check what type of plug or plugs can connect to the machine before picking up a generator cord for a supplier.
In general, large standby generators will come with either 3- or 4-prong twist-lock plugs since they can connect directly to your home’s transfer switch. Most modern homes use 4-prong twist-lock plugs, but it’s still rather common to find homes with 3-prong plugs.
If you’re planning on plugging in heavy machinery and tools into your generators, such as splitters, water pumps, and power tools, you’ll want to get a cord with the right receptacle. There are other 3- and 4-prong designs that don’t twist-lock that deliver power directly to the aforementioned machines.
Amperage
Although the power of a generator is measured in watts, generator power cords are measured in how many amps they can handle. The rule of thumb is that the higher the amperage rating, the more electricity the generator power cord can handle. If you have a good eye, you can spot the differences between 50- and 20-amp power cords by the thickness of the cord (more on this later).
Keep in mind that you can easily damage low-amp cords by plugging them into high-amp outlets in your generator. If you have a 30-amp 3-prong outlet, only get a 30-amp cord.
Wattage
Even though the amperage rating of a generator power cord is the main figure to look at, this doesn’t mean you can ignore how many watts the cord can handle. It’s a good idea to look for a cord that has a slightly larger wattage capacity than your generator. For instance, if your machine can provide up to 5,000 running watts, try and find a cable that can support 6,000 or 7,000 watts.
Cord Length
You never want to place a generator indoors, whether it’s an indoor, outdoor, or even inverter generator. You also never want to place the generator too close to your home or RV since it’s going to be producing a lot of noise. This calls for finding a generator power cord that’s long enough that it can connect your generator to a transfer switch from a faraway distance.
However, although you want a long power cord, you will get diminishing returns in regards to how much power travels through the cord. The voltage will drop when you use excessively long cords, making your generator incapable of effectively providing energy to your home.
Wire Gauge
If you find that you need a super-long cord but are afraid that the cord’s length will cause an insufficient flow of power to your home or appliances, then consider checking out generator power cords with larger wires. The thickness of the inner copper wires varies depending on how much power is expected to flow through the cord.
A thinner wire is used in small appliances and electronics like lamps and chargers. Larger appliances like refrigerators require a thicker wire for power to flow more freely through. If you don’t have the right type of wire gauge, you risk causing damage to your electronics.
Cord Durability
Since your generator is going to be placed outdoors, you should purchase a generator power cord that’s able to withstand all sorts of weather conditions. Try and find cords that are covered in a waterproof casing, so it does not become damaged during the rainy months. You also should be aware of the potential of little critters nibbling away at your cord. The good thing is that most name-brand generator power cords are designed to handle the elements and the jaws of small, woodland creatures.
Generator power cords are typically made of three different types of synthetic plastics – thermoset, thermoplastic elastomer, or thermoplastic. Thermoset is the strongest material of the three and is covered in a thick layer of sturdy rubber. The thermoplastic elastomer is the middle ground between heavy-duty thermoset and thermoplastic, and it works exceedingly well in cold environments and during wintertime. Thermoplastic is the lightest-duty of the three and is best-suited for use indoors and away from the harsh elements of nature.
Letter Patterns
Most first-time buys and even experienced generator owners don’t really pay much attention to the letter patterns when choosing a generator cord. In all honesty, it’s not exactly the biggest of deals, but it’s still a good idea to get to know what these letters mean.
There are ten different letter ratings assigned to generator power cords which describe how the cord should be used, what materials are used to make the cord, and what the cord is designed to withstand. A single generator power cord can have multiple letters assigned to it. The letters and their meanings can be found below.
S = Severe Service Cord, up to 600 volts
SJ = Junior Severe Service Cord, up to 300 volts
T = Thermoplastic
N = Outer-jacket made of nylon
E = Elastomer, a rubber-like thermoplastic
H = Heat resistant
O = Oil-resistant coating
OO = Oil-resistant coating and insulation
W = Resistant to weather and water, suited for both indoor and outdoor use
V = Vacuum, for plugging in vacuum cleaners
Top Generator Power Cords
Our brief buying guide above should give you a general idea of what specs to consider when scouring the market for a reliable, high-quality generator power cord. However, a quick internet search will show you thousands of different cords with different plugs that serve different purposes, and it can all be overwhelming. We’ve compiled a list of our picks of the five best generator power cords, all with commonly used plugs, for you to check out.
5 Miady Generator Cord
The first 125/250-volt generator cord on our list is from Miady. This generator power cord is meant to hook up to a 30-amp outlet and supply power to your home or RV via the 4-prong twist-lock plug. This cord is rated SJTW – up to 300 volts, made of thermoplastic, and safe for use outdoors). This power cord can support up to 7,500 watts, so it’s compatible with many standby and portable generator models.
This is a heavy-duty, 40-foot long cord that lets you place your generators far away from a transfer switch so the droning noises coming from your machine won’t reach you. There’s no need to worry about an insufficient flow of power through the cord since it’s made of 10-gauge wiring.
Something fancy that Miady provides for you is a handy carrier that wraps and tightens around the cord. When not in use, coil up the cord and clamp it all together using the carrier. This small additional is extremely useful in saving storage space by letting you hang the cords without any risk of them uncoiling and falling to the ground.
There have been some complaints regarding the plug. The 4-prong design is unlike what you’d have in an inlet box. Those who have differently shaped inlet box outlets need to sand down the extra ridges on the prongs to get the cord working properly. This doesn’t affect performance, but it’s a nuisance not having the cord ready for use straight out of the box.
4 Champion 25-Foot Generator Extension Cord
The next generator power cord on this list is a 25-foot 120V/30-amp extension cord from Champion.
This cord doesn’t connect your generator to your home or RV’s electrical system, but instead, you can plug this into the 3-prong 30-amp receptacle in your generator and supply power to up to three different appliances. This extension cord offers three 15-amp 3-prong outlets.
This SJTW-rated cord is made of thermoplastic and can withstand harsh weather conditions including snow and rain. Basically, with this cord on hand, your generator will be able to provide power to three different appliances without having to inhale the toxic fumes coming from your generators.
This cord is 25 feet long and is made of durable 10-gauge wire. It’s built to sustain flowing electricity of up to 3,750 watts. We ask that customers exercise caution when using this cable since there is no protection for the individual outlet, and if the generator is overloaded, the three outlets will go down.
Keep in mind that this cord isn’t meant to power your home or RV, but instead takes power from your generator and lets you connect three appliances directly to it with a maximum of 3,750 watts. Like an extension cord, this is one of our favorites for locking in extremely well in your generator’s receptacle and for being resistant to most weather conditions.
3 Conntek 20602 L14-30 Generator Cord
Next on our list is the 20602 from Conntek. This is a heavy-duty, 50-foot, 4-prong power cord that connects to your generator to your home or RV’s inlet box. The power cord is rated STW for up to 600 volts, made of thermoplastic, and is resistant to water and other outdoor conditions. The 20602 can handle up to 7,500 watts of energy so many standby generators and most portable generators can use it.
Due to the super-long length of the cord, you can place your generator up to 50 feet away from your inlet box. This means while you won’t even hear a peep coming from your generator while you enjoy the power it supplies.
And you also don’t have to worry about the cord’s extremely long length affecting its performance. The 20602 comes with 10-gauge copper wire, finely stranded, so the cord, although flexible, will maintain flawless delivery throughout its lifespan.
However, there is one tremendous issue that only a few customers have realized after purchasing this item: it contains lead. The lead is found under the rubber coating which is rather durable, so even though there’s a very little risk that you’ll expose yourself to lead when handling this power cord, you should be aware of any possible risks.
2 Reliance Controls Corporation PC3040
Next, we have the PC3040 from Reliance Products. This 40-foot long generator power cord, 4-prong connects directly to your home or RV’s inlet box for uninterrupted power from your generator. This product has been repeatedly called one of the best SJTW (up to 300 volts, made of thermoplastic, and water and weatherproof) cables by numerous customers and industry experts.
This cord connects to the 30-amp 125/250-volt receptacle in your generator and delivers up to 7,500 running watts. Within the thermoplastic casing, we can find a 4-wire setup using 10-gauge copper wires for maximum flexibility and durability. Length is no issue since the wires are thick enough to transport electricity without any drop in power.
To back up the company’s claim of high-quality products, they’ve included a 5-year warranty for the PC3040. So far there haven’t been any notable complaints about this product in terms of performance and durability, so we’re rather optimistic that if you get this cord, there won’t be anything to regret.
Although there haven’t been any negative reviews about this product regarding its performance – in fact, Reliance Products is one of the leading manufacturers of generator power cords.
This is the problem; since Reliance has become the go-to company for generator power cords, there are several knock-offs from questionable companies using the Reliance name and selling their shoddy merchandise. You have been warned.
1 MPI Tools Nema L14-30 40 Generator Power Cord
The number one product on our list of the five best generator power cords is this one from MPI Tools. Like most of the generator power cords on our list, this is a 30-amp, 4-prong cord that delivers. This is an STW cord that is designed for heavy-duty use and to withstand whatever nature has to offer.
Like the other cords on this list, this 125V/250V power cord from MPI Tools has a capacity of 7,500 running watts, making it able to deliver whatever many standby generators and most portable generators have to offer. When lighting up your home with a generator, you don’t want your cord to slip from the inlet box, leaving you and your family in total darkness until you can reconnect the cord. Those troubles are over if you get this handy cord that’s made to stick with a twist.
This 40-foot cord relies on four sets of 10-gauge copper wires for optimal delivery of electricity without experiencing any drops in power. The long cable allows you to place your generator at an optimal distance so you won’t be disturbed by your generator’s constant hums.
Final Remarks
Whether you’re preparing for a disaster that could potentially knock your power out, planning a trip in your RV, or need to power up heavy-duty machines in the middle of the woods, you’re going to need a generator. However, a generator is nothing without having the right power cord.
Connecting your generator to your home’s transfer switch and plugging in appliances directly to your generator both require having the appropriate cords so you can supply power safely to your home and electronics.
Before you order a generator power cord from the internet, be sure that you understand what your generator can do and how to use it. The first thing you should do is check out what type of receptacle your generator has. There are three main types: duplex output plugs, TT plugs, and twist-lock plugs. These plugs have specific code names that you can find in your owner’s manual.
Apart from knowing what type of plug to look for, there are several other factors to take into account when looking for the right power cord. These include the amperage rating, how many watts the cord can support, the length of the cord, what gauge wire it has, and the materials and durability of the cord.
If you pay close attention to the cord, you’ll see letter patterns such as SJTW or STW, showing how many volts it can deliver and how durable it is to water.
If you’re still confused about what type of cord to purchase, take a look at our picks of the five most reliable generator power cords. We’ve also included an extension cord if you want to plug in appliances to your generator and now use your generator to power your home or RV.
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