DIN EN 61663-1 VDE 0845-4-1:2000-07

The document deals with the protection of telecommunication lines in fibre optics installations against lightning. The object is to limit the number of possible primary failures occurring in the optical fibre cable in a particular installation within values which are lower than or equal to the tolerable frequency of primary failures and the tolerable risk of primary failures. Hereto the standard describes a method for the estimation of the possible failure current and of the risk of primary failures. Then a procedure for the decision if protection measures are necessary is described and feasible protective measures are explained. Secondary failures are not considered.