IEC 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

Objective is to limit the number of possible primary failures occurring in the optical fibre cable in a specified installation to within values which are lower than or equal to the limit value, defined as the tolerable frequency of primary failures.Gives the method for calculating the possible number of primary failures, choosing the feasible protective measures and indicating the tolerable frequency of primary failures.Secondary failures are not considered.The tests described in annex G are convenient only for the risk evaluation associated with lightning in fibre optic installations. Tests for the qualification of a cable design are outside the scope of this standard.