Specifications

172
NLUO PMC CONTRACTOR
SIGNATURE AND SEAL SIGNATURE AND SEAL SIGNATURE AND SEAL
TECHNICAL SPECIFICATION FOR CABLE INSTALLATIONS
1. General :
All HV cables (up to 33 KV earthed system) shall be XLPE insulated aluminium conductor cable conforming to I.S. 692 and
I.S. 7098 respectively.
All medium voltage and Low Voltage PVC insulated FRLS type and armoured / unarmoured cables shall conform to I.S. 1554
Part-I-1964 and of 1100 volt grade.
Old and used cables must not be used for installation. Only one make of cable shall be used. All cables brought to site must be
tested and got approved by the Engineer-in-charge before these can be laid. The cables shall be dispatched to site on wooden
drums with ends sealed. Exact lengths shall be determined by the Contractor after measurement at site.
The underground installation of cables shall be generally conforming to I.S. 1255-1967, Code of practice for installation and
maintenance of underground cables (upto including 33 KV).
2. Laying of cables :
(a) Direct in Ground :
Trenches shall be 750 mm deep (minimum) for LT cables and 1.2 M (4’-0”) deep minimum for HT Cables from ground level
and trenching work shall including all pumping and bailing out water. These trenches shall be wide enough to accommodate all
the cables with brick separations as per the requirements specified in the relevant I.S.
When more than one multicore cable is to be laid in the same trench, a minimum horizontal interaxial spacing between cables
will be as per relevant I.S.
After excavation of the trench of proper size, the bottom of the trench shall be dressed and leveled and filled with 75 mm layer
of fine sand. The cable shall then be laid with bricks on both sides of the cable continuously. After having the space within the
bricks, filled and packed up to a level of 75 mm (3”) above top of cable with fine sand, the top layer of bricks shall be placed
side by side in continuous series as protective cover. Total No. of bricks required being 16 per metre run. The remainder of the