Ethernet cables are convenient for several reasons. For instance, they give you a secure network connection and they’re also easy to install. However, your devices still need the power to work and depending on your setup or other nearby items, your ethernet and electrical cables are usually run next to each other. But could this cause a problem?
You can run ethernet cables next to electrical cables if the ethernet cable is shielded, but even then you should keep 8in between them. Non-shielded cables can lose data and bandwidth when run next to power cables. PoE cables run too close to power cables can cause heating and fires.
So, you can run the two cables together assuming that the ethernet cable is shielded, however, there are a few things that you have to pay attention to. And if you have to run them together, there are ways of getting around some of the issues that come from running the cables together. Let’s dive in and cover the details of how to get this right.
Can You Run Network Cable Along Existing Power Cables?
It’s generally recommended to have at least eight inches of space between power cables and network cables, and ideally more than 12 inches. This helps to prevent interference and ensure optimal performance. This is driving most of the issues with installs that run the cables together. So, the best practice is basically – no – you shouldn’t do this if you want to optimize for both safety and data integrity along the way (so the cables don’t interfere with each other).
If you need to run cables in close proximity to each other, there are a few options for spacing them properly. One option is to use cable ties or clips to keep the cables separated and organized. Another option is to use conduit or raceway to enclose the cables and prevent them from touching.
Obvioucly we’re going to go into all the details on this, but, before we go too far we just wanted to give you a clear understanding of the problem: you can convince yourself this is OK in your unique situation, but the flat recommendation si to not run your cables directly together if you can avoid it, when it comes to data and power. Even if they’re all well shielded.
When You Can Run Cables Together
It’s generally agree that lower electrical power voltages cause less of an issue here. So, you can run low voltage communications cables together in the same pathway without issues, including coaxial cable, Ethernet cable, and low voltage fire alarm cable. That said, we doubt many readers have low-voltage power lines running through their house. Probably the only low-voltage cable you have is in the backyard on outdoor lights, if you have any at all (and you probably don’t need to run ethernet out there).
That said, you can obviously run cables together some times without expecting any issues. But in the case of a 120V or higher line run through your house, you want to protect your ethernet cable from being next to that.
Note: Cable Distance Can Also Be An Issue
We’re going to talk about the ways power can interfere with data signals if you run them together in this article, but you also need to watch out for flat degradation due to the length of the cable. You may think you have interference when you’re just using an ethernet cable that’s too long.
This happens sometimes, especially in installs where you’re running cables through the walls, because that’s when you’re more likely to be using very long ethernet connections. The max length for cables is not exact, but the standard actually calls out 100 meters for Cat5/Cat6 (forum link)
, so about 300 ft for our US readers. If your cable is longer than that, you may start having issues form the length of the ethernet cable.
Pro Tip: Just Use Your Power Cables For Internet! (Powerline Adapters)
OK, I promise we are going to get to the meat of this article, but you have to know about another option now because it can save you SO MUCH TIME in pulling ethernet cables through your walls. I’m talking about using another kind of technology called Powerline Adapters (example on Amazon).
Powerline adapters are devices that allow you to send data through your home’s existing electrical wiring, eliminating the need for in-wall Ethernet cables or relying on potentially unstable Wi-Fi. These adapters work by using your home’s electrical wiring as a network, with one adapter plugged into an electrical outlet near your router and the other adapter plugged into an outlet near the device you want to connect to the network.
The adapters then communicate with each other through the electrical wiring, allowing for a stable and secure connection without the need for additional cables. This can be a convenient and cost-effective solution for extending your network from point A to point B without the hassle of running cables through walls or relying on unreliable wireless connections.
What’s the catch? Well, there aren’t any free lunches. This is a simple solution, but, it’s also a bit janky. You should expect a powerline setup to cut your available up and download speed, maybe as much as 90%.
The Effects of Running Ethernet Next to Electrical Cable
It’s easy to simply run the cables together, but have you thought about the effects? It may be easier, especially when running long lengths of cable, to run them next to each other or even wind or twist them together to make one “mega-cable”, but the electricity on the power line can lead to interference that degrades the quality of the ethernet signal. And for ethernet cables that have Power over Ethernet (PoE), the mismatched voltages also lead to some unexpected interactions.
Safety and Data Integrity
Running a low and high-voltage cable close to each other isn’t always a great idea. For example, there are safety concerns that also affect data integrity. The National Electric Code (NEC) states that voltage induction is a risk when a high and low voltage cable is laid next to each other, in fact, the higher voltage can jump to the cable with the lower voltage.
Not only is there a risk for an electrical fire, but you could also find yourself with a nasty shock. The higher voltage that’s now in the ethernet cable will damage data and the connected device. If you do have to run an ethernet and electric cable in the same area, you can take some steps to prevent safety hazards and damaged data. One of the best steps you can take is to make sure you’re getting high-quality, well-shielded cables.
Difference Between Shielded and Unshielded Ethernet Cables
Shielded Cat5 and Cat6 cables provide the same function as unshielded ones, and that is that they provide power and data to the connected device. Shielded Ethernet cables have a thin foil cover protecting the wires from interference.
The interruption in data can be caused by other devices, including electrical cables. The shielding works to block interference improving data integrity and speed. Shielded Ethernet cables may also be a little larger than the non-shielded ones.
The Limits of Protection from Ethernet Shielding
There are times when you want to use shielded ethernet cables. If you a lot of electromagnetic interference (EMI) from other devices, the foil wrap embedded in the shielding will improve performance. You can even bury CAT 5 and CAT 6 weatherproof shielded cables outside. Sometimes you need the ethernet to run to an outdoor camera, so you definitely need a well-shielded cable for this use.
Even though shielded cables give you protection from EMI interference, there are limitations. The shielding does not block all interference. Depending on the nearby devices, you can still have problems with the cable’s performance. Ultimately, this is why you want the cables or other sources of interference to just be physically distant from the ethernet cable, at least by a few inches.
If you have other electronic devices nearby, especially large ones like elevators and data processors EMI can still be a problem. You can further reduce interference with a shielded Cat 6 cable (on Amazon). It’s larger and better equipped to block “crosstalk” between the circuits.
We should also note: while we think Cat 6 cables is plenty for most people, if you want to know more about the different types of Ethernet cables (CAT6 vs. 7 vs. 8), check our our related article picking that apart.
Are Shielded Ether Cables More Expensive?
Shielded Ethernet cables (our deeper-dive article) can be more expensive. They’re also harder to install because one end of the cable must be grounded. You can only connect it to another grounded and shielded component. It applies to network devices, jacks, and couplers.
You can’t use a non-shielded cable with a shielded one. So, while a better shielded and groundable ethernet cable like the Phizli Cat7 Outdoor Ethernet Cable (on Amazon) is slightly more expensive, it also means upgrading all the links in the chain of your system a little bit, and that cost can add up. That said, for the protection your gaining, the cost is typically well worth it.
Best Practices for Running Ethernet and Electrical Cable Together
Sometimes you can’t avoid running an ethernet and electrical cable together. If you find yourself in this situation, you want to do it safely and protect data integrity. Here are a few tips on how to run the cables together.
Pay Attention to Cable Distance
Believe it or not, but the cable distance is also a factor, in fact, the National Electric Code (NEC) has specific distance guidelines for running power and ethernet cables together. Depending on the cable types, you don’t want them closer than two inches. Any closer and your violating safety codes and risking data loss and induced voltage issues. Here are the main guidelines:
- Unshielded ethernet cable can’t be closer than 8 inches to a 120V or 240V household electrical cable.
- The lower voltage household cables can be moved closer if the ethernet cable is shielded. But you don’t want to go closer than 2 inches.
This is the NEC specific for running the two cables together, but it only covers voltage safety and not data integrity. Even a shielded cable can have problems blocking EMI when a 120V power cable is 2 inches away. If both safety and data protection are concerns, keep the cables 8 inches apart.
Don’t Run the Cables Parallel
It’s easy to run the cables parallel, that much is for certain, but the problem is you’re increasing the risk for interference. The low voltage in the ethernet cable is necessary for data transfer. It generates the magnetic field that sends and receives information. The high-voltage cable can interrupt the magnetic field and cause interference.
You can limit the problem by crossing the cables perpendicularly. The right-angle crossing prevents the power cable from disrupting the ethernet cable’s magnetic field. The number of times you cross the cables depends on the length.
Running Cables Past Other Devices
Take a look around at the devices near the cables. It’s surprising what can cause interference. Fluorescent lights, elevators, and machinery motors all emit a type of noise that can disrupt the data signal.
This means you should take the time to not only survey the surroundings but also move things out of the way if you can. While elevators are not a big issue at the residential scale, you should consider avoiding any large electrical equipment in your home when planning your cable run.
Research & Follow All Applicable Standards (NEC, NFPA, OACG, etc.)
Following NEC standards is the easiest way to lay a power and ethernet cable together. You know the exact needed to keep the cables safely apart, no matter the type. The standards also let you know which cables need grounding, along with how to safely connect them to devices. There are a few other applicable standards, so, we’ll lay them all out here. NEC is the most prominent, which is why we started with it, but The National Electric Code (NEC) and National Fire Protection Act (NFPA) both provide guidelines for electrical safety.
These guidelines are not technically law, though local municipalities may indeed adopt the NEC into law with or without changes, so it’s important to know your local code requirements and consult with the Authority Having Jurisdiction (AHJ) if needed. This means literally calling your power company, probably, if you have any questions. We recommend that as much faster and easier than trying to read through and understand all the technical standards!
The other applicable guidelines – Outdoor Aerial Cable Guidelines (OACG) – doesn’t seem like it would be relevent at first! After all, you’re not installed Aerial cable. Nevertheless, section 800.44 (outdoor) of this guideline, as well as section 805.133 (indoor) should also be in your toolkit if you’re trying to follow the guidelines.
The gist of the OACG recommendations are: for outdoor aerial cable guidelines, communications cables should be attached below power cables or lighting, and a minimum separation of 12 inches must be maintained between supply service drops and communications cables. For indoor guidelines, communications cables can be run in the same pathway as other low voltage cables, but should not be run in the same pathway as 120V or higher electrical wiring without a listed divider or permanent barrier.
Check Your Cables After Installation
After the cables are laid, you want to check and make sure that everything has been installed properly. For example, if you’re using shielded cables, make sure one end is grounded. Look for any equipment that can interfere with data transfer rates. Finally, test the data speed over the cable and make sure you’re getting the stability and bandwidth you’re expecting!
Uncrossing Your Wires
You can run an ethernet cable next to an electrical cable, but it’s not the best idea. It is easy and convenient. Your setup also looks better when the cables are combined. The downsides are safety and the integrity of your data. Power cables often disrupt the magnetic field created by the ethernet cable’s low-voltage properties.
The magnetic field is necessary for a smooth data transfer. The other problem is the two cables together pose a fire hazard. When your only option is running the cables together, you want to keep them 8 inches apart and go for a Cat 6 shielded cable. You have better protection against interference.