PRODUCTS

                                 
HEAVY DUTY ARMOURED AND UNARMOURED CABLES
HEAVY DUTY ARMOURED AND UNARMOURED CABLES
Type Application Max. Conductor Temperature
A Insulation 70 °C
C Insulation 85 °C
ST1 Sheath 70 °C
ST2 Sheath 90 °C
 
CORE IDENTIFICATION
For Power cables and Control cables upto 4 cores ,the cores are identified by different colours as per IS:1554

Single core : Red ,Black ,Yellow, Blue 
3 core : Red ,Yellow ,Blue 
3.5 core : Red ,Yellow ,Blue and reduced neutral core in Black 
4 core : Red ,Yellow ,Blue ,Black 
5 core : Red ,Yellow ,Blue , Black ,Grey 

Where the number of cores exceed 5,two adjacent cores are BLUE for reference and YELLOW for direction in each layer.The remaining cores in each layer are GREY.

On specific request we can also provide core numbering for control cables.
PRODUCT CODE
As per IS : 1455 -Part 1-1988 ,the product is coded by alphabets :
  
Aluminium Conductor  A
(No abbreviations are used for Copper)
PVC Insulation Y
Steel round wire armour W
Steel strip armour F
Steel double round wire armour WW
Steel double strip armour  FF
PVC outer sheath Y
AI wire armour AW

This product code is stenciled on the surface of the drum flange.
Note : Conductor construction classified as :
re : single strand 
rm : multi-stranded circular 
sm : sector shaped 

Note :The entire range of Power and Control cables can also be supplied with Flame Retardant Low Smoke (FRLS) sheathing.

BASIC ASSUMPTION FOR CURRENT RATINGS

1. Maximum Conductor Temperature 70 °C for GPPVC insulation & 85° C for HRPVC insulation 
2. Thermal resistivity of Soil 150 °C cm /w 
3. Thermal resistivity of PVC 650 ° C cm /w 
4. Ground Temperature 30 ° C 
5. Ambient Air Temperature 40 ° C 
6. Depth of laying(to the highest point 
    of cable laid direction the ground)		 75 cms 
7. Type of Installation
Multicore cables
Single cables
Installed Single 
Three Single core cables installed in trefoil & touching formation. 

 Cables shall only be operated at their full rating if the minimum current at which circuit protection is designed to operate does not exceed 1.5 times (in the case of cables in air or in ducts ) or 1.3 times ( in the cables laid directly in the ground)
THE CURRENT RATINGS GIVEN IN TABLES 1 TO 6 ARE BASED ON NORMAL CONDITIONS OF INSTALLATION
1. Rating factors for Depth of laying
  
Depth Of Laying cm Upto 25 mm˛ Above 25 mm˛ Upto 300 mm˛ Above 300 mm˛
75 1.00 1.00 1.00
90 0.99 0.98 0.97
105 0.98 0.97 0.96
120 0.97 0.96 0.95
150 0.96 0.94 0.92
180 or more 0.95 0.93 0.91

2. Rating factors for depth of laying (Twin and multicore cables in single way ducts)

Depth Of Laying cm Rating Factor
75 1.00
90 0.99
105 0.98
120 0.97
150 0.96
180 0.95
270 0.92
360 0.91
450 0.90
540 or more 0.89

3. Rating factors for the single core cables (AC) in flat formation in air (to be applied to the corresponding ratings 
for trefoil groups in air)

 Nominal Area of conductor in mm2  Rating Factor
Upto & including 185 1.07
240  1.10
300  1.08
400  1.04
500  1.00
630  1.00

4. Rating factors for variation in Ground Temperature for cables laid direct in ground

Ground Temperature°C 15  20  25  30  35  45 40 
Rating Factor 1.17 1.12 1.06 1.00 0.94 0.87 0.79

5. Rating factors for variation in Ground Temperature for cables in ducts

Ground Temperature°C 15  20  25  30  35  40  45
Rating Factor 1.17 1.12 1.06 1.00 0.94 0.87 0.79

6. Rating factors for variation in Ground Temperature for cables in ducts-

Air  Temperature°C 20  25  30  35  40  45  50
Rating Factor 1.33 1.25 1.16 1.09 1.00 0.90 0.83

Note : For cables in air no reduction in current rating is necessary provided that

1.The horizontal clearance between circuits is :
a. not less than six times the overall diameter of an individual cable and,
b. not less than the overall width of an individual circuit except that the horizontal clearance need not exceed 150 mm in any case.

2. The vertical clearance between circuits is not less than 150 mm.

3. If the number of circuits exceeds 4 ,they are installed in horizontal plane.

However ,for installation conditions other than above current rating factors incorporated in IS : 3961-Part II may please be applied.

The following points should be taken into consideration before selecting particular size & type of cable :

1.The system of power & voltage source where the cables are being used.
2.Conditions of installation at site.
3.Current carrying capacity of cable.
4.Voltage Drop of cable.
5.Short circuit capacity of cable.
6.Availability of the selected size of cable.

Short Circuit rating in K.amp for One Second Duration

Area of Conductor Sq.mm Aluminium Conductor PVC  Aluminium Conductor HRPVC Copper Conductor PVC Copper Conductor HRPVC
1.5 0.1126  0.097 0.169 0.153
2.5 0.1878 0.162 0.283 0.255
4.0 0.3004 0.259 0.452 0.406
6.0 0.4507 0.389 0.679 0.612
10.0 0.7512 0.648 1.132 1.020
16.0 1.200 1.087 1.810 1.632
25.0 1.870 1.620 2.830 2.550
35.0 2.620 2.270 3.960 3.570
50.0 3.750 3.243 5.660 5.100
70.0 5.250 4.540  7.920 7.140
95.0 7.130 6.150 10.750 9.690
120.0 9.000 7.784 13.580 13.340
150.0 11.260 9.730 16.980 15.300
185.0 13.890 12.000 20.940 18.870
240.0 18.020 15.560 27.160 24.480
300.0 22.530 19.460 33.960 30.600
400.0 30.040 25.940 45.280 40.800
500.0 37.560 32.430 56.600  51.000
630.0 47.320 40.860 71.310 64.250

Formula for calculating the Short circuit current for other duration's
It = I1 / (t)0.5
It = I1 / (t)0.5

Where :-
It : Short Circuit Current for t seconds
I1 : Short Circuit Current for one second
t : Duration in Seconds 

Maximum conductor temperature during short circuit is 160°C for both PVC and HRPVC cables.