AVOCAB is one of the largest manufacturer of variety of cables and an established name in India as well as abroad. AVOCAB Wires and Cables are most preferred with numerous installations throughout the country. The range of products includes Power Cables, HT XLPE , LT XLPE And PVC Cables, Instrumentation Cables, House wires and Flexibles. AVOCAB HT XLPE Cables up to 33 KV are manufactured at its modern manufacturing set up at Chattral. Technological up gradation and Polymer revolution has Replaced the conventional paper insulated cables and thermoplastic insulated cables with cross linked Polyethelene (XLPE) having Better electrical, mechanical and thermal properties with reduced cable weight and dimensions. Worldwide acceptable trends are adopted by AVOCAB’S aim is to manufacture cables of highest quality and to provide customer satisfaction that is unparalleled in the industry.
- Higher Electrical Strength Retention
- Higher Short Circuit Rating
- Better Electrical, Mechanical & Thermal Property
- Easy Jointing & Termination
AVOCAB manufactures following voltage grade cables as per IS: 7098 (Part 2), IEC -60502 and BS -6622.
1) 6.35/11 KV (E) , 11/11 KV (UE) , 12.7/22 KV (E), 19/33 KV (E), 33/33 KV (UE) Cables. 2) 12.7/22 KV Cables (22 KV Earth) 3) 11/11 KV i.e. 11 KV (UE) Cables 4) 6.6/6.6 KV Cables [ 6.6 KV (UE) & 11 KV (E) ] 5) 3.8 /6.6. KV Cables 6) 3.3 KV (E) and (UE) Unscreened / Screened Cables. |
SIZE 50 Sq.mm to 1000 Sq.mm in Single Core Cables. 25 Sq.mm to 400 Sq.mm in Multi Cores Cables. |
Flame Retardant (FR), Flame Retardant Low Smoke (FRLS) and Flame Retardant Zero Halogen (FRZH) Sheathed HT XLPE cables are also manufactured.
The XLPE cables are manufactured on sophisticated triple Extrusion line, in highly quality conscious environment with Testing and Inspection from raw material to finished cables. The assurance of quality is further ensured by ISI certification on cables.
Estimated Voltage Drops in |
||||
Nominal area Of conductor |
P. V .C Cable |
XLPE Cable |
||
Single phase |
Three phase |
Single phase |
Three phase |
|
1.5 |
43.44 |
37.62 |
46.34 |
40.13 |
2.5 |
29.04 |
25.15 |
30.98 |
26.83 |
4 |
17.78 |
15.40 |
18.98 |
16.44 |
6 |
11.06 |
9.58 |
11.80 |
10.22 |
10 |
7.40 |
6.41 |
7.88 |
6.82 |
16 |
4.58 |
3.97 |
4.90 |
4.24 |
25 |
2.89 |
2.50 |
3.08 |
2.67 |
35 |
2.10 |
1.80 |
2.23 |
1.94 |
50 |
1.55 |
1.30 |
1.65 |
1.44 |
70 |
1.10 |
0.94 |
1.15 |
1.00 |
95 |
0.79 |
0.68 |
0.83 |
0.70 |
SELECTION CRITERIA OF MV/ HV CABLE SIZE FOR PRIMARY DISTRIBUTION SCOPE
The conductor size in the cables for any installation is also governed by its ability to carry short circuit current of system. For L.V Distribution cable may be selected on the basis of continuous load current. But in case of MV /HV distribution it is always safer to select the cable on the basis of ability of conductor to carry expected short circuit current. Short circuit current rating of cable should in line with short circuit capacity of demanding apparatus such as circuit breakers, Transformer & Reactor etc. beside its capacity to carry desired load current . Short circuits rating of cables each size are given in relevant tables & have been calculated on the basis of IEC -949 & IEC -986 & on the following assumption
i) With XLPE Insulation – 90 Deg. C
ii) With PVC Insulation – 70 Deg. C
i) With XLPE Insulation -250 Deg. S
ii) With PVC Insulation – 160 Deg. C
i) With Aluminum conductor – 2.5 x 10 -3 J/Deg. C/MM3
ii) With Copper conductor – 3.45 x 10 -3 J/Deg. C/MM3
i) With Aluminum conductor -228
ii) With copper conductor – 234.5
Ish ( for t duration ) = Ish ( for 1 sec .) /t
Ish for 1 Sec .Duration is given in relevant tables in KA
t = Time duration required tobe calculated of short circuit in sec.
Estimated Voltage Drops in |
||||
Nominal area of conductor |
PVC CABLE |
XLPE CABLE |
||
Single phase |
Three phase |
Single phase |
Three phase |
|
120 |
0.63 |
0.55 |
0.66 |
0.56 |
150 |
0.52 |
0.46 |
0.55 |
0.48 |
185 |
0.42 |
0.37 |
0.44 |
0.40 |
240 |
0.34 |
0.30 |
0.35 |
0.30 |
300 |
0.28 |
0.26 |
0.30 |
0.26 |
400 |
0.24 |
0.22 |
0.24 |
0.22 |
500 |
0.23 |
0.20 |
0.23 |
0.20 |
630 |
0.20 |
0.18 |
0.21 |
0.18 |
800 |
0.90 |
– |
0.20 |
– |
1000 |
0.18 |
– |
0.18 |
– |
Above voltage drops (volts/km/amps) shall be multiplied with rated current & length of cable in K.M to calculated total voltage drops in particular length and size cables.
SELECTION CRITERIA OF H.V. /MV CABLES FOR PRIMARY DISTRIBUTION
REQUIRED DATAS | FOR EXAMPLE | |
1 | Nominal system voltage at H.T.side | 11 KV |
2 | Short Circuit level for H.T. system | 2.5 KA |
3 | Fault withstands time for H.T. CBs | 0.5 Sec |
4 | Formula for calculating H.T. cable size |
With Cooper cond. /XLPE Insulted cable = Ish x √t / 0.143 = 25 x √0.5 / 0.143 = 124 Hence nearest higher size 150 mm is required