Cables shall be laid on GI trays, overhead structures or through GI conduits with rigid supports at one meter intervals to avoid sagging.
Signal, power and compensating cables shall be laid in separate GI trays with minimum separation of 300 mm.
Partial run of signal cables and power cables shall normally be avoided but where parallel runs must be made, tray spacing of at least 300 mm shall be provided. In case of laying on overhead structure cable spacing of 300 mm shall be provided. Otherwise cables shall be run through GI conduits.
Crossing of power, signal and control cables shall be made at right angles only.
GI trays shall be mounted with their breadth in vertical plane to protect cable from falling objects and accumulation of dust. If trays are laid horizontally, these shall be provided with removable covers and shall be supported by rigid base to avoid sagging.
Use of elbow / bends shall be avoided, instead larger radius bends shall be
provided for ease of laying and avoiding breakage at the bends.
Multicore cable shall not be bent to radius less than the manufacturer’s
Intermediate joints shall be avoided. If not avoidable, joints shall be made
preferably in junction boxes. However, for compensating cables no jointing is
Clips and saddles securing cables to steelwork or tray shall preferably be plastic
covered material and shall be spaced at 0.5 m interval.
All cables shall be suitably identified with their tag numbers duly clamped at an
interval of 5 m. Tag plate should include Cable No. and size as per scheme.
FRLS cables shall only be used through a fire-hazard areas.
Cable entry into junction boxes or panels shall be through removable gland plates
and compression glands suitable to withstand vibrations.