15 Best Practices for Fiber Optic Cable Installation in Data Centers

CABLExpress recently released its latest Fiber Optic Cabling Best Practices Guide, a set of guidelines for pre-, post- and during-installation of the company’s Skinny-Trunk cabling products based on its own field experience, in accordance with the TIA-942 data center standard.

“These guidelines help improve operations by minimizing the risk of failures due to inadequate planning, improper handling of fiber cabling, improper testing, and reduced installation time,” CABLExpress said.

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Best Practice Tips contains a lot of general cabling installation knowledge. As a representative sample, we have extracted the top 15 guidelines with key quotes as follows:

1. Do port mapping

"This diagram should include cabinet locations, patch panels, hardware, port counts, trunk locations, and power access connection points... The goal of the design is to minimize future errors caused by obstructions in high-traffic areas, difficult cable access, loose and unprotected connections. The goal of the design is to maximize efficiency by efficiently using the loss budget."

2. Preparation for optical cable installation (A)

Inventory all components received on site to match against the materials list provided with the design… Ensure you have all tools and materials needed to complete the installation including: Velcro and cable management, scissors for removing kinks, trash bags for packaging, fiber cleaners (if needed), and cable labels (if needed).

3. Preparation for optical cable installation (B)

“Remove all products from their cardboard packaging before bringing them into the data center…fibers from the cardboard packaging can become airborne and damage hardware within the data center.”

4. Establish a labeling system

Your label numbering scheme should match the TIA-606-C published standard for all patch cords and jumpers, labeling by: cabinet number, rack unit, port location, or labels specified in ranges…For longer lengths, label the trunk cable at both ends with length, origin, and destination information.

5. Determine the cable connections and staggered lengths

The cable's branch length is the distance from the bifurcation point (where the individual cables separate from the combined single jacket) to the connector end. These branch lengths can be staggered to plug into specific ports, patch panels and/or hardware.

6. Determine the fiber service loop

A service loop is created when extra length is added to a cable for emergency situations. A short service loop (3 to 6 feet) is helpful when using an estimated length to cut trunk lengths if needed. This extra length allows the option of moving patch panels or enclosures within the cabinet…The disadvantage of a service loop is that the cable path may experience excessive congestion…Whether a service loop is managed vertically on the side of the cabinet or horizontally at a specific rack unit is determined by the data center operator.

7. Be careful with Cat6 copper cable repair loops

“If growth is anticipated, it can be helpful to allow patch panels with fiber and copper service loops to be moved within the cabinet. However, in a typical server cabinet, copper service loops can quickly become unmanageable…Copper trunks are thicker and stiffer than fiber trunks. Copper cabling can also experience negative performance impacts from crosstalk when too many cables are bundled together or when space is tight…If the cabinet is 2 feet wide and less than 4 feet deep, plan for minimal service loops, or no service loops at all. If the cabinet is 2 feet wide and less than 4 feet deep, plan for minimal service loops, or no service loops at all.”

8. Color code your cables

TIA-606-C documents the official standard for cable colors. Beyond that, you can choose specific colors for your data center, defining the specific factors of your choice. But be consistent.

9. Manage forks

When securing fiber trunk cables to an enclosure, rack, or cabinet, use zip ties only at the breakout point of the trunk. The breakout point is designed for this purpose because it has a metal sleeve to protect the fiber…For all other applications, use only Velcro. Using zip ties directly on the fiber jacket may break the fiber.

10. Check/clean the optical fiber

“Before insertion into a port or patch panel, the installer must inspect the surface of the fiber optic glass end (ferrule) with a microscope and, if necessary, clean the connector with a one-touch cleaner. After cleaning, inspect again before insertion… The protective cap should remain on until just before the cable is installed.”

11. Use cable management

When installing fiber optic patch cords and copper patch cords from a patch panel to active ports within the same cabinet, use a combination of horizontal and vertical cable management to route cables from the left side of the patch panel to the left active ports and from the right side of the patch panel to the right active ports.

12. Do not bend, knot or pinch the fiber optic cable.

13. Don’t pull too hard

14. Perform post-installation testing

Transmission performance depends upon cable characteristics; connecting hardware; patch cords; cross-connect cords; total number of connections; and proper precautions during installation and maintenance. Results of tests immediately after installation [should include]: continuity; short circuits; transposed, reversed, or split pairs, [and] ground conductors.

15. Reporting Test Results

The fiber link should show the measured attenuation value, the limit tested, and the link length in the report or database. The test document package should also include the following: the test date; the name of the tester; the identification of the field test instrument used, including the manufacturer, model and serial number, and the latest calibration date of the test instrument. The test results should be provided in soft copy and hard copy form.