Захист волоконно-оптичних кабелів.
Optical Cables with OKM metal elements in the structure ( ply protective shell, power components, copper wire for transmitting remote power supply) must be protected against lightning and hazardous effects of electromagnetic power lines and electrified railways AC as required by the LPC 45-136.
Protection of cables against lightning strikes OCM if necessary, may be provided by:
— seal lightning conductors;
— choice cable is protected against lightning, eliminating the need pads protective conductors (wires).
Consistent protection of cables ECM (without copper conductors) from the induced effects and dangerous lightning strikes must be provided with one of the following methods on :
1 ) compliance with the conditions of continuity of the screens ( shell ) in the sleeve to ensure grounding cable repeater stations and an earth shield ( sheath ) of the cable to the couplings in the places where you want to limit the voltage " screen — the land " to below the normalized ;
2) the interruption of the metallic screen ( shell ) of the cable within the calculated lengths or in each box or an additional intermediate points to the expected value of the induced voltage between the screen and the ground was within the rated values.
Protection of cables from OKM galvanic effects that may occur near the power transmission line in case of emergency on power lines, it shall be subject to allowable distance between the cables and the support ( grounded ) power lines .
Coordinated protection from galvanic effects of lightning strikes and is determined mutually satisfactory compliance with the allowable distance between the cable and power transmission poles, which are listed in Section 7.
Protection against dangerous effects of power lines and electrified railways AC optic cables with copper conductors OCM designed for remote power shall be in accordance with regulatory requirements specified in 8.5.
Due to the low efficiency of the shielding properties of the metal shell is not recommended that ground along the path to its possible use as an electromagnetic shield .
Optical cables without metallic structural elements ( dielectric cables BAS) are not subject to the influence of electromagnetic high voltage power lines, electric railways and do not require protection from lightning .
OKD cables are recommended for laying tracks in areas characterized by high grozodeyatelnostyu and increased resistivity of the earth.
In the case of the optical cable OKD project addressed issues of protection of the dielectric cable from damage by rodents.
An excerpt from: VBI B.2.2-45-1-2004