CFOT - Certified Fiber Optic Technician Installation and Hardware Questions and Answers

Question 1

An installer is pulling an outside plant (OSP) fiber optic cable with a 0.5-inch diameter through a conduit. To prevent damage, what is the generally accepted minimum bend radius that must be maintained *during* the installation?

Accepted Answer

10 inches (20x the diameter)

Answer

Industry standards, such as those from the FOA and TIA/EIA, recommend a minimum bend radius of 20 times the cable's outer diameter while the cable is under pulling tension. After installation, when the cable is static, the minimum bend radius is typically relaxed to 10 times the diameter. For a 0.5-inch cable, 20 times the diameter is 10 inches.

Question 2

A technician is installing fiber optic cable in a building's plenum spaces, which are used for environmental air circulation (HVAC). According to the National Electrical Code (NEC) Article 770, which cable rating is required for this application to minimize fire and smoke hazards?

Accepted Answer

OFNP (Optical Fiber Nonconductive Plenum)

Answer

The National Electrical Code (NEC) specifies that cables installed in ducts, plenums, and other spaces used for environmental air must be listed as having adequate fire-resistant and low smoke-producing characteristics. For nonconductive optical fiber cables, the OFNP (Plenum) rating is the highest and is required for installation in plenum air spaces to prevent the spread of fire and smoke.

Question 3

During a cable pull, a breakaway swivel is used as a crucial piece of hardware. What is the primary function of this device?

Accepted Answer

To disconnect the pull rope from the cable if the pulling tension exceeds a preset limit.

Answer

A breakaway swivel is a safety device designed to protect the fiber optic cable from excessive pulling tension. It is engineered to separate at a predetermined tension level, which is set below the cable's maximum rated pulling force. This ensures the fragile glass fibers inside the cable are not damaged by being stretched or stressed.

Question 4

A technician is preparing to clean fiber optic connectors before mating them. Which of the following is considered a best practice in the 'wet-to-dry' cleaning method?

Accepted Answer

Wiping the connector end-face first on a solvent-dampened area of a lint-free wipe, then moving to a dry area of the same wipe.

Answer

The recommended 'wet-to-dry' or 'combination' cleaning method involves using a lint-free wipe or cassette cleaner with a small amount of approved fiber optic cleaning solvent. The end-face is wiped from the wet area to a dry area in a single, straight motion to dissolve contaminants and then wipe away any residue without leaving streaks or re-contaminating the surface.

Question 5

What is the primary safety concern a technician should be aware of when handling and disposing of bare fiber scraps after stripping and cleaving?

Accepted Answer

The glass shards are sharp and can easily penetrate skin or eyes, causing injury.

Answer

Bare fiber scraps are tiny, sharp shards of glass that are difficult to see. They can easily embed themselves in a technician's skin, causing painful splinters, or worse, get into the eyes. If ingested with food or drink, they can cause internal hemorrhaging. For this reason, all scraps must be disposed of properly in a sealed and clearly labeled sharps container.

CFOT - Certified Fiber Optic Technician Practice Test

CFOT - Certified Fiber Optic Technician Practice Test

CFOT - Certified Fiber Optic Technician Installation and Hardware Questions and Answers