| Installation Conditions |
| 1. Continuous operating temperature of conductor |
|
| a) PVC type-5 insulated |
85° C |
| b) XLPE insulated |
90° C |
| 2. Ambient temperature |
52° C |
| 3. Temperature of ground |
35° C |
| 4. Depth of laying in ground |
|
| a) LV Cables |
750 mm |
| b) MV Cables |
1000 mm |
| 5. Thermal resistivity of soil |
1.2° C .m/W |
| |
| OTHER CONDITIONS |
| A. LOW VOLTAGE CABLES 600/1000V |
| 1. SINGLE CORE CABLES |
| i) Two cables spaced one cable diameter installed vertical in air. |
| ii) Two cables spaced one cable diameter laid horizontally underground. |
| 2. MULTI CORE CABLES |
| i) Single cable touching wall installed in air. |
| ii) Single isolated buried cable in ground. |
| iii) Single cable installed in single isolated buried ducts - |
| a) Duct Material |
Earthen Ware |
| b) Depth of laying |
i) LV Cables : 750 mm
ii) MV Cables : 1000 mm |
| c) Duct diameter |
| i) Cable dia. up to 65 mm |
OD = 130mm & ID = 100 mm |
| ii) Cable dia. above 65 mm |
OD = 160 mm & ID = 125mm |
| |
| B. MEDIUM VOLTAGE CABLES 6.6 KV TO 33 KV |
| 1. SINGLE CORE CABLES |
| i) Three Cables, trefoil, in air, two point bonding, separated from wall. |
| ii) Three Cables flat with a gap of one cable diameter installed vertically in air, separated from wall. Single point or cross blonded. |
| iii) Three Cables with gap one cable diamenter laid horizontally underground |
| 2. MULTI CORE CABLES |
| i) Single cable touching wall installed in air. |
|
| ii) Single isolated buried cable in ground. |
|