Τηλεπικοινωνιακά καλώδια - Μέρος 2-27: Κοινοί κανόνες σχεδιασμού και κατασκευής - Μείγματα μανδυών με βάση πολυολεφίνη χωρίς αλογόνο για καλώδια που έχουν βελτιωμένες ιδιότητες φλόγας και πυρκαγιάς

This document gives specific requirements for halogen free polyolefin based sheathing compounds used for halogen free communication cables with improved characteristics in the case of fire. Compounds, described by this document, are commonly also named HFFR or HFFR-LS (halogen free, flame/fire retardant, low smoke), see also EN 50290 2 20. It is expected to be read in conjunction with EN 50290 2 20, the product standards EN 50288 series, EN 60794 series and other applicable product standards. Improved characteristics in the case of fire are demonstrated by specific fire tests on cables for flame/fire retardant applications (e.g. single or bunched cable fire test). Additional tests to prove the characteristics in case of fire, e.g. such as smoke emission test, might also be part of the dedicated product standard or specification. This document describes the compound types as given in Table 1. Table 1 — Sheathing compounds Compound grades Max. operating temperature Comment Type 1 70°C thermoplastic standard Type 2 90°C thermoplastic, higher temperature Type 3 90°C crosslinked, higher temperature