EN 61663-1 : 1999

1 Scope and object
2 Normative references
3 Definitions
4 Reference configuration
5 Construction characteristics of the cable
      5.1 General
      5.2 Failure current for buried cables
      5.3 Failure current for aerial cables
6 Need for protection
7 Protective measures
      7.1 General
      7.2 Dielectric or metal-free cables
      7.3 Choice of cable characteristics for both
             buried and aerial installations
      7.4 Use of shield wire for buried cables
      7.5 Route redundancy
Annex A (normative) Frequency of primary failures, Fp for
                    buried and aerial cables and for cables
                    entering a structure exposed to direct
                    lightning strokes
Annex B (normative) Sheath breakdown current ls for both
                    buried and aerial cables
Annex C (normative) Shielding factor values
Annex D (normative) Route redundancy for both buried and
                    aerial cables
Annex E (informative) Damage correction factor Kd
Annex F (informative) Tolerable frequency of primary
                      failures Fa
Annex G (normative) Tests for surge current resistibility
Annex H (informative) Procedure for determining the failure
                      current
Annex I (informative) Bibliography
Annex ZA (normative) Normative references to international
                     publications with their corresponding
                     European publications

Concerned with the lightning protection of telecommunication lines in fibre optic installations. Limits the number of possible primary failures that occur in the optical fibre cable in a specific installation to within values not exceeding the limit value, defined as the tolerable frequency of primary failures.