What you need to know about Cold Weather and Fiber Optic Cables!
Winter is here, and with it comes freezing temperatures, snow, sleet and ice storms! The temperature drops, the cold rolls in, and then the snow starts falling at a rapid pace.
The snow accumulation can lead to outages that can affect your ability to get work done. Have you ever noticed when the snow starts to fall, so do your fiber optic internet speeds? You’ve noticed, and so have your customers! Freezing-cold temperatures seem to take a toll on fiber optic cables and cause them to stop working suddenly in some cases. The calls are going to start to coming soon, so you need to be ready to troubleshoot and answer their questions!
There are so many advantages that come along with using fiber optic cables over traditional copper ones. Fiber optic cables can transmit data much faster than standard copper wires. They can also carry more data over further distances – without disruptions! Many advantages come with installing fiber optic cables over traditional copper cables, but that doesn’t mean they are invincible. Over the years one of the big challenges associated with fiber optic cables has been the cables poor performance during colder weather.
So – What gives? Does the cold weather actually effect the quality of your fiber optic connection, or just a random coincidence? To answer your question – the actual cold temperatures do not affect the quality of your connection. However, some of the byproducts of the cold will cause issues with your fiber optic cables. Mainly due to freezing cables inside the conduits due to condensation and infiltration.
Freezing cables in an innerduct or conduit has been happening as long as cables have been put into ducts, but fiber optic cable is susceptible to freezing in a way that traditional copper cables are not. There is quite a bit of research that has been done on it, and it appears as though fiber optic cables are affected by cold temperatures whenever water is able to make its way into the ducts housing the cables, and then the water freezes. The ice that forms around the fiber optic cables often causes the cables to bend, which affects the signals sent through the cables. If water has the chance to enter into the housing of your cables and freeze, then your overall internet performance will deteriorate. Depending on how extreme the bending is, the signals may not be able to pass through the fiber optic cables at all. It can lead to fiber optic networks going down unexpectedly. Loss of connectivity can be inconvenient to any business that relies on fiber for day-to-day operations. Signal strength usually returns to normal as the ice melts.
How does water get into innerducts? It gets in by infiltration and condensation. Picture an innerduct as a hose laid out along the road with occasional access points. Water infiltrates these access points and flows downhill, which could lead to hundreds of gallons of water being present in the system. As long as the innerduct is buried below the frost line, no freezing will occur. Where a fiber optic cable is exposed to freezing temps, such as at an exposed bridge crossing, ice can form in the duct. In many cases field techs entered an innerduct, and water poured out for several minutes.
Condensation is another possible culprit, especially at exposed bridge crossings where differences between the ambient temperature and the inside innerduct regularly exist. Just as condensation forms on a cold glass, condensation can form inside innerducts and conduits.
Fortunately, there are preventative steps you can take when installing your fiber optic cables to ensure that your cables are not affected and that your connectivity is not interrupted.
First, when installing fiber cables, carefully plan out where they are installed. Often, burying the fiber optic cables below the frost line will help greatly reduce and may even eliminate the threat of ice. If, for some reason, you are unable to install your cables below the frost line, there are antifreeze gels and other preventative measures that can help prevent water from freezing inside the ducts. These products have proven to be useful when it comes to protecting fiber optic cables from the elements.
Most fiber optic freeze-ups have also been found to occur two to three feet within the head wall of a bridge. Freeze-ups are similarly a problem in abandoned pipelines where the pipes are exposed or placed on a cantilever when they cross creeks or rivers.
Several companies have sought to remedy this issue by constructing along railroad rights-of-way and attaching carrier pipes to the sides of any bridges or culverts they encounter, or by laying a carrier pipe on the bridge deck. This is far more economical than placing the cable underground by means of a directional boring device.
Although temps in the lower forty-eight states may reach -40°F (with a wind chill exceeding -80°F) the temperature inside the conduit underground will not drop below about 25°F. Fiber optic cable in a conduit will not experience temperatures below the ambient outside temperature; as wind chills only affect exposed surfaces.