Installing service loops

Q: I have worked with many cabling subcontractors, and they terminate fiber and UTP cable differently. Most of the subcontractors will leave a service loop of 7 to 21 feet at either end of a fiber run, but typically leave no slack in UTP runs. What is the acceptable installation procedure for maintenance or service loops for Category 5 UTP cable and indoor fiber?

Steve Campbell

Electronic Data Systems

Plano, TX

A: The bicsi tdmm recommends providing slack at both ends of horizontal cable runs to accommodate future cabling systems changes. The recommended lengths are: a minimum of 3 meters in the telecommunications closet for both twisted-pair and fiber cable, and 1 meter for fiber and 30 centimeters for twisted-pair cable at the outlet.

Note: Generally, the length of service loop that is required is stated in the construction specifications.