Smart Buildings

2 Big Mistakes to Avoid During Fiber Cable Installation

Massimo Carboni

Thorough cleaning and proper pulling: These two factors are key to achieving a high-quality fiber cable installation. Get best practices here.





We’ve seen it all when it comes to fiber cable installation: the good, the bad and the unbelievable.


Every day, we talk to technicians and contractors in the field who install our fiber cables in data centers and broadcast, AV, industrial and smart building applications. By spending time on jobsites, we get to provide hands-on training, answer questions and learn more about where and how our products are used.


While we observe installation in a variety of environments, we’ve also noticed a major disconnect between the industry’s recommended best practices for fiber cable installation and the actual practices being carried out in real life.


Here are two of the biggest fiber installation mistakes we encounter in the field, along with tips to make sure these things don’t happen on your own jobsites.


1. Fiber cleaning procedures that are too relaxed


Contamination is the biggest cause of fiber optic link failure. For that reason, the industry’s message has always been this: Fiber should be clean, clean, clean! But we still see some installers skip or take shortcuts on fiber cleaning.


A lack of cleaning altogether may cause higher optical loss, while incorrect cleaning can degrade the performance of the network. The importance of cleaning fiber during installation can’t be stressed enough.


But installers are busy. When deadlines are tight, oversights can happen in an effort to save time. For example, we’ve seen installers take these actions (and these are some of the worst shortcuts you can take during fiber cable installation):

  • Dip their fingers in rubbing alcohol or isopropyl alcohol and then wipe endfaces with their fingertips to clean them.
  • Rub the ends of fiber connectors on their shirt before plugging them in.
  • Use an all-purpose disinfectant wipe to quickly clean the end of a fiber cable before connectorization. 

There’s no getting around the fact that proper cleaning takes a little longer—but it pays off in big ways. Ensuring clean fiber connections is critical to support speed and reliability. You want the fiber infrastructure to be as clean as it can possibly be. Dirty fiber is a surefire way to reduce your yield, introduce possible performance problems and increase service calls down the road.


How to prevent problems caused by incorrect cleaning:

There are many fiber cleaning options to choose from, including:

  • One-click cleaners, which use a dry cleaning strand to lift dust, debris and oil from the connector endface.
  • Inspection scope cameras that make it fast and easy to check fiber endfaces. These autofocus cameras provide a sharp view of the endface in a few seconds for a detailed inspection. While you can visually confirm cleanliness without a tool, or use a manual inspection scope, these cameras offer the most accurate results.
  • Cleaning kits, which include everything you need to establish clean fiber connections. 

No matter which cleaning tools or methods you choose, be sure to follow these fiber cleaning tips for best results:

  • Don’t use canned air or dusters (they blow particles around and don't clean oils or residue).
  • Don’t touch fiber connector endfaces.
  • Don’t touch the solvent dispensing tip.
  • Wear appropriate safety glasses.
  • Keep protective caps on unplugged fiber connectors.


2. Incorrect fiber cable pulling 

We regularly see incorrect pulling during the installation process. This leads to fiber cable failure.


Pulling a fiber cable beyond its maximum pulling force can cause cracks, kinks or breaks that impact performance. Most fiber cables include special strength members (made of a material like aramid yarn) for cable pulling. They protect the optical fibers inside the cable from damage and provide a way for installers to safely pull the cable during installation.


We’ve seen installers mistakenly pull on the cable jacket instead of using the aramid yarn. Doing this stretches the cable jacket and impairs the optical fibers inside. Stretching the outer jacket leaves the optical fibers a few feet farther down the cable instead of at the end and won’t provide a secure termination. The jacket may also tear or break or look wavy.


Pulling cables against something tight, such as around a corner or alongside other fiber cables, can also burn the outer jacket.


How to prevent problems caused by incorrect pulling:

When pulling fiber cable, follow these recommendations to avoid damage:

  • Cut some jacket off to access and pull on the strength members only—not the cable jacket or the cable itself.
  • Never exceed the maximum pulling load.
  • Maintain the cable’s minimum bend radius and be sure not to bend it beyond that; this may increase attenuation and break the fibers.
  • Avoid twisting or pinching the cable when pulling it.


Have fiber installation questions?

Our goal is to help you provide quality installation work. Taking time to follow best practices for fiber cable installation is just one more way you can stand out in an increasingly competitive industry.


Belden’s fiber team is here to answer your installation questions and guide you through recommended best practices to ensure a proper installation so you can make the most of your cable investment. No question is too basic. If you have a question, let us know. Our team will get back to you soon with helpful information to guide your installation in the right direction.


Related resources:

How Do Fiber Optic Cables Work? Your Question Answered

How to Know When to Use Fiber Optic Cable