PVC INSULATED POWER & CONTROL CABLES
PVC Cables have been introduced to replace the conventional paper insulated cables used in transmission and distribution systems. Moreover, the use of aluminum cables has been permitted in place of copper cable up to 6.6 kV.
PVC Cables have got certain technical and economical advantages for certain applications. The outstanding properties could be identified as follows:
All Cables design covered conform to IS: 1554 (Part 1 & 2) for working Voltage up to 6.6 kV
- High Resistance to ageing and abrasion.
- High mechanical strength,
- Moisture-proof, corrosion-proof, weather-proof.
- Resistant to effects of the majority of acids and alkalis.
- Resistant to occasional temporary contact with oils and liquid fluids,
- Flame-retarding-does not support combustion and is self-extinguishing when the source of ignition is removed.
- Easy to install.
- Neat appearance.
- Light weight.
- Good bending properties.
- Smooth surface.
- Easy Stripping of conductor ends.
- Elimination of indoor cable boxes (three phase conductors can be directly connected to distribution boards/motors terminal boxes).
- High resistance to D.C. voltage effects.
- Suitable at steep gradient.
During the process of change over to cables with plastic insulation and sheathing, tremendous amount of development work had been done with the result that PVC Insulated Power and Control Cables have been firmly established not only for industrial and other applications but also for power transmission.
Basic Design: NICCO Brand PVC Power and Control Cables are manufactured confirming to IS: 1554 (part 1 & 2)
Conductor: Conductors of nominal area less than 16mm² shall be circular only. Conductors of nominal area 16mm² and above may be circular or shaped.
Cables with reduced neutral conductor shall comply with the Main Power conductor combination.
Insulation: The conductors are insulated with PVC compound by extrusion process.
Inner Sheath: The cores of multicore cables are laid up and the surrounding by PVC covering either by PVC extrusion or by wrapping.
Application : Armoring shall be applied over the insulation in case of single core cables and over the inner sheath in case of twin-three and multi-core cables.
Type of Armor : Where the calculated diameter below armoring does exceed 13mm the armor shall consist of galvanized round steel wires. Where the calculated diameter below armoring does not exceed 13 mm the armor shall consist of either galvanized round steel wires or galvanized steel strips. Single Core Cables are generally armored with wires of non-magnetic materials.
Outer Sheath : This is provided by means of extruded PVC over the armor for armored cables; over inner sheath for unarmored cables and over the insulation for single core unarmored cable. Unarmored multicore cables shall have mono sheath (single extrusion covering inner and outer sheath.
PVC usually used to manufacture the type of cable is general purpose PVC suitable to operate at a maximum conductor temperature of 70°C.
HR PVC Cable : Nicco also manufactures power cables using heat resisting PVC Compound. (Type C/ST2 & OF IS: 5831). HR PVC Cables can be operated at a maximum conductor temperature of 85°C and are also suitable for intermittent use at temperature 105°C.
LV XLPE POWER CABLE
NICCO has been manufacturing XLPE (Crosslinked Polyethylene) insulated cables for voltages ranging from 1.1 kV to 66 kV. The manufacturing method for LV XLPE cable (1.1 kV & 3.3 kV) is different to that of MV & EHV XLPE insulated cables. NICCO manufactures 1.1 kV & 3.3 kV LV XLPE cables using SIOPLAS Technology.
Sioplas Technology - SILANE Process :
Silane Crosslinkable Polyethylene compound is curable by exposure to moist conditions for insulation of Power Cables. This compound is based on a high molecular wet polymer and it is especially developed for Low Voltage cable insulation.
This compound utilises the system for Crosslinking of - Polyethylene known as SIOPLAS. It is a two component system comprising of silylated ethylene polymer known as the graft copolymers and a masterbatch material containing a crosslinking catalyst, the two materials normally being added in the rating of 95:5. This system thus attain a high level of crosslinking in the processed form and the finished product has all the properties associated with crosslinked polyethylene cable.
- Higher current rating permits to select lower size of XLPE cable compared to PVC cables
- Higher short circuit rating than PVC cables
- Resistant to heat deformation while PVC is prone to heat deformation
- Repetitive short circuit/overload condition is reliable
- Lower Dielectric Loss
- Lighter weight considering lower overall diameter
- Ease of handling & jointing