LT PVC Power Cables Suppliers & Manufacturers In India

Power cables are used to transmit and distribute electrical energy. Power cables are commonly used in urban underground power grids, power station lead-out lines, power supply within industrial and mining enterprises, and over-the-river transmission lines.
PVC insulated cables are manufactured up to 1000 sqmm(Single Core) and 630sqmm(Multi Core) conforming to IS, IEC & BS standards.
PVC insulated cables are suitable for use on AC single phase or three phase (earthed or unearthed ) systems for rated voltage upto and including 1100 volts. These cables can be used on DC systems for rated voltage up to and including 1500 volts to earth.

Construction:

General Construction – LT PVC Power Cables upto 1.1 KV

Conductor:

The most acceptable metals for conductors are copper and aluminium due to their higher conductivity and ductility.As copper has got higher affinity for sulphur, it corrodes in the atmosphere where sulphur fumes are present. In these conditions tinned copper should be used. Aluminium oxide film which is always present on Aluminium conductor surface acts as barrier and it protects the Aluminium conductor from corrosion in fumes laden atmosphere.

The following types of conductor construction is used in manufacture of LT cables

Solid/Stranded

A)Solid:

The conductor is made of one solid wire. Solid conductors can be used upto 6 sq.mm with copper conductor and 10 sq.mm with aluminium conductor.

B)Stranding:

In this the conductor is made of multiple wires (strands). Stranding makes Cables flexible and easy to handle. For example, in case of 16sq.mm six strands are laid around one central strand making it a total of 7 strands.

Circular/ Shaped

A)Circular:

In this the conductor is circular in shape.

B)Shaped:

A sector conductor is a conductor whose cross-section is approximately the shape of a sector of a circle. A multiple conductor insulated cable with sector conductors has a smaller diameter than the corresponding cable with round conductor.The sector shaped conductor are manufactured with pre-spiral lay which gives compact shape to the cable with reduced diameter at laid up stage

National specifications IS:8130

International specification IEC:60228 / BS:6360

Insulation:

The PVC covering over conductor is called insulation and is provided by extrusion process only. The insulated conductor is called core.Poly-Vinyl Chloride (PVC) as per IS 5831, IEC 60502-1, BS 7655.

I.S. 1554 permits two types of PVC insulation as follows:

We offer both general purpose PVC of 70°C (Type A) and Heat Resistant PVC of 85°C (Type C) as per IS: 1554.

Laying Up:

The cores are laid up with suitable layto form a compact circular shape. The final layer always has a right hand lay i.e. if you look along the cable, the cores move to your right hand.

Inner Sheath:

Inner sheath of PVC either extruded / tape is provided over the overall shield.PVC / LSZH innersheath is applied as a protection over the laid up cores and to provide a bedding for the armour. Innersheath can be offered in two forms Extruded or Taped.

A)Extruded Innersheath:

Here the innersheath is provided by extrusion of Thermoplastic over the laid up cores.This type of the innersheath also acts as a water barrier between cores and outersheath. It is anExtruded PVC bedding of ST1 or ST2 PVC as per IS 5831, IEC 60502-1, BS 7655.

B)Tapped Innersheath:

Here the innersheath is provided by wrapping a thermoplastic tape over the laid up cores. Taped Bedding of Thermoplastic tape is compatible with temperature rating of the cable as per IS 1554-1, IEC 60502-1.

Armouring:

Galvanised Steel Round Wire as per IS 3975, IEC 60502-1, BS 10257.

Galvanised Steel Flat Strip as per IS 3975, IEC 60502-1.

For Single Core cables to be used in AC circuits Aluminium Round Wire or Flat Strip armour is provided to avoid magnetic hysteresis losses.

In mines, the resistance of the armour in no case should exceed the resistance of the main core by more than 33% for safety reasons. To achieve this, sometimes tinned hard drawn copper wires are required to be used along with galvanized steel wires. Or two layers of Round Steel Wire or Steel Strip are applied in opposite direction with barrier tape in between to give extra protection.

Outer Sheath:

The PVC covering over the armouring in case of armoured cables and over the Innersheath in case of unarmoured cables is called outersheath. The thickness of outer sheath is generally determine as per the relevant national and international standards. Many compounds can be used as sheath material. Different grades are available to meet specific working conditions

PVC / LSZH outersheath is applied by extrusion process and is generally black in colour (Other colour on request) with sequential length marking and required details printed with either non-contact ink jet printer or by embossing on the cable. Cables with special properties of FR and FRLS, ZHFRLS are also manufactured.

Advantages of PVC Cables:

• A non-hygroscopic insulation almost unaffected by moisture.
• Non-migration of compound permitting vertical installation.
• Complete protection against most forms of electrolytic and chemical corrosion.
• A tough and resilient sheath with excellent fire resisting qualities.
• Good ageing characteristics.
• Not affected by vibration.

The following colour code is used for identification :

No of Cores	Colors as per IS 1554 part 1	Colors as per IEC 60502-1	Colors as per BS 5467 (A:2008)
1	Red, Black, Yellow or Blue.	Red or black	Brown or blue
2	Red and Black.	Red & black	Brown & blue
3	Red, Yellow and Blue.	Red, yellow and blue	Brown black and grey
3.5	Red, Yellow, Blue and Reduced neutral Black.
4	Red, Yellow, Blue and Black.	Red yellow blue black	Blue, brown, black and grey
5	Red, Yellow, Blue, Black & Grey.	Red, yellow blue black and green/yellow	Green/yellow, blue, brown, black, grey
6	By printing numbers on each core.	By printing numbers on each core.	By printing numbers on each core.