2 Big Mistakes to Avoid During Fiber Cable Installation

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.

Two of the most critical steps—fiber optic cleaning and fiber cable pulling—are also the ones most often done incorrectly. Cleaning failures can lead to poor network performance or even equipment damage, while improper pulling risks physically damaging the fiber before it’s even in place. Learn more about these installation mistakes we encounter in the field, and how to prevent them. Read more about how fiber optic cables work.

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 optic cleaning, which can negate some of the benefits fiber cabling offers.

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

Excessive signal loss, increased reflectance and even permanent damage to connector endfaces and active equipment are possible when cables aren’t properly cleaned. Even a tiny dust particle can block or scatter light.

The hidden cost of skipping fiber optic cleaning

When deadlines are tight, oversights can happen in an effort to save time. For example, we’ve seen installers take these actions when they’re rushed (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.

Recommended fiber cleaning tools

New connectors should always be cleaned before they’re used. Fiber connectors should be cleaned every single time before they are mated. Use an inspection scope to confirm the endface is free of contamination before making the connection.

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

• One-click cleaners, which use a dry cleaning strand to lift dust, debris and oil from the connector endface.
  
  
• Automated inspection scopes  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 use a manual inspection scope, these automated cameras offer the most accurate results.
  
  
• Cleaning kits, which include everything you need to establish clean fiber connections.

Dry cleaning (such as one-click tools) works well for loose particles, while wet cleaning is better for oils or more stubborn contamination. Always follow wet cleaning with a dry-cleaning step to ensure nothing is left behind.

2. Incorrect fiber cable pulling

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

Pulling fiber optic cable correctly is a critical step. Excessive pulling force, tight bends and cable jacket damage can compromise optical performance before the system is turned on. Small mistakes at this stage may not show immediate effects but can create long-term signal loss or premature cable failure.

The risks of improper fiber cable pulling

Pulling a fiber optic 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 strength members. Doing this stretches the cable jacket and impairs the optical fibers inside. Stretching the outer jacket can displace 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 fiber optic cables against something tight, such as around a corner or alongside other fiber cables, can also burn the outer jacket.