How Temperature Affects Ethernet
No one ever said that networking is easy. There’s a lot to learn and consider in order to make a great and robust network.
A lot of times, people stick with Ethernet because it is powerful, simple, and very cost-effective. If you’re using Ethernet, there’s a lot to gain, but there are still some issues you need to know about, and one of them is temperatures. So, let’s take a few minutes to learn exactly how temperature affects Ethernet.
How Does Temperature Affect Ethernet?
So, what actually happens when Ethernet cables get really hot or cold? The answer actually depends on whether the problem is heat or cold. In either case, temperature extremes are bad for Ethernet, so let’s look at exactly how that unfolds.
High Temperatures
Let’s talk about heat first. When an Ethernet cable gets really hot, it experiences signal degradation. Effective transmission rates start to decline, and when things are hot enough, you can lose all signal through the cable.
At what temperatures will you experience this?
It turns out that getting the temperature above 20℃ (68℉) is enough to start noticing signal degradation. As temperatures go up, the degradation increases, and at temperatures above 75℃ (167℉), Ethernet cables often stop working.
Now, these are average numbers. The exact performance by temperature will vary from cable to cable, but these ballpark figures can help you think about heat and your cables.
It’s worth noting that you can account for this signal degradation by shortening the Ethernet cables. At room temperature, 100-meter runs are normal and fine for Ethernet. As the temperature goes up, you can shorten those runs and maintain the speeds you need. Until the temperatures get to extreme highs, this trade-off can keep you in business.
Low Temperatures
What about cold temperatures?
When an Ethernet cable is exposed to low temperatures, the materials making up the cable contract. This can lead to a few things.
You may have noticed that the exterior of Ethernet cables are usually rubbery to the touch. This is shielding that protects the cable from a lot of risks. Inside are copper pairs, and without shielding, you run into a lot of problems.
Bringing this back to temperatures, the sheaths on standard Ethernet cables become brittle at cold temperatures. As soon as you get below freezing temperatures, the sheaths are at a much higher risk of breaking.
Now, if the cables aren’t moving, this brittleness doesn’t matter too much until you get well below freezing (specific temperatures are discussed below). The long and short of it is that brittle cables are not ideal.
There’s a second issue to consider. Very low temperatures cause copper to contract. This can exacerbate issues with the cables. Shrinking copper can fail to connect at junctions, and any small damage to copper along the lines can expand from thermal contraction. In short, cold temperatures can highlight and intensify existing problems with the cables.
What Are Normal Temperatures for Ethernet?
There are a lot of different Ethernet cables in the world, and various manufacturers and even specific cables made by the same manufacturer can maintain different specifications. In other words, you should always double-check the safe operating temperature range for your specific cables. This is often notated as the “ambient temperature range.”
While these temperatures are different from cable to cable, there is a large average that can give you an idea as to what temperatures Ethernet cables can reasonably endure. More often than not, the ambient temperature range for an Ethernet cable is -40 to 75℃.
For those who operate in Fahrenheit, the typically ambient temperature range is -40 to 167℉. If you think your cables will endure temperatures anywhere near those numbers, double-check the specifications for your cables and take appropriate options.
Installation Temperatures
It’s important to note that the ambient temperatures relate to normal operations. If you are installing Ethernet cables, the numbers change. The safe installation temperature range (still double-check your cables as they could be an exception) is -20 to 75℃.
To emphasize this point, Ethernet cables can’t handle the same extreme colds when you install them. This is because of how cold impacts the cables. The risk of cracking and damaging the cables is very high below these temperatures, and that risk is exacerbated when you maneuver cables around in order to install them. Static, unmoving cables are not likely to crack in low temperatures (unless those temperatures drop below the ambient safe level).
How Can You Adjust Ethernet for Extreme Temperatures?
So, what do you do if your cables need to endure extreme temperatures? It all boils down to two things: insulation and testing.
If you compare outdoor-rated cables to indoor cables, you’ll notice a difference right away. The outdoor cables are thicker. Actually, the copper pairs inside of the cable are the same. The difference is found in the shielding. Outdoor environments are usually a lot tougher than indoor environments so you need more insulation and shielding for the outdoor cables.
This concept applies to any Ethernet cables in extreme temperatures. Wrap them with more insulation, and they can withstand greater temperature ranges. It really is that simple.
Of course, testing is also your friend. If you’re not sure how much insulation is needed or whether or not your cables are up to a task, test them. First, test them in a normal environment to set a baseline. Then, test a small cable run in your real environment to see if the performance is up to your standards. Pass these tests before you invest in your full cable runs. This will save you tons of time and money.
In the end, if you run your cables and they pass your tests, the specification recommendations don’t matter too much. What matters is how the network performs, and if yours is meeting demand, then you’re in good shape. If you remember how temperature impacts Ethernet before you commit, then you can perform smart tests and avoid major problems.
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