Difference between XLPE and PVC Cables

Difference between XLPE and PVC Cables

XLPE - is cross linked polyethylene cable. 

Main Thumb rule for differentiation is that XLPE cables can be used for both HT and LT lines.
But PVC Cables can be used only for LT lines.

XLPE can withstand a higher temperature than PVC without detriment. This means that more current can be conducted for the same cross sectional area of copper. This means a big saving in cables costs. 

XLPE Cables useful properties are:-

1. Temperature resistance
2. Stress rupture resistance
3. Environmental stress crack resistance
4. Resistance to U.V light
5. Chemical resistance
6. Oxidation resistance

XLPE Cables can be useful for following applications:-

1) XLPE cables work for the working voltage of 240 V to 500 KV .
2) Conductor Material can be either Copper or Aluminum.
3) XLPE cables can be either Single Core cables or Multi core cables depending upon the number of
cores.
4) They can be Unarmoured or Strip Armoured or Wire Armoured or Tape Armoured type depending upon the presence or absence of Armour.
5) HT / LT Aerial Bunched Cables


Polyvinyl chloride Cables useful properties are :-

They are commonly abbreviated as PVC, insulated cables are widely used in various fields.
PVC's Cables are generally have following Properties:-
1. Low cost
2. Chemical resistance
3. High tensile strength
4. Better flexibility

For, electric cables the PVC is mixed up with plasticizers.
Low voltage copper conductor PVC cables are extensively used for domestic home appliances wiring, house wiring and internal wiring for lighting circuits in factories, power supply for office automation, in control.
PVC CABLES
1) Power Cables upto 1.1 KV
2) Multicore Cables upto 61 Cores
3) Sheilded instrumentation Cables
4) FRLS / FR / HR / Fire Survival Cable 

-> Electrical, mechanical, weather ability contrast table:

Properties	XLPE	PVC
1. Chemical Structure	Thermoset, pure Hydrocarbon. Non-Polar C-C or Si-o-Bonds	Thermoplastic Polar Rotosenated. C. Ci. Bond
2. Polymer Structure	Partial Crystalline	Amorphous
3. Long-term Working Temperature	90℃	70℃
4. Emergency overload	130℃	90℃
5. Highest working temperature of short circuit	250℃	160℃
6. Carrying capacity(A)	1.25a	1a
7. Dielectric constant(20℃,60Hz)	2.3	8
8. Cable Installation Job	Easy due to less Wt, less Diam and Less Bending radius.	Not Easy Like XLPE
9. Service life (year)	30	20
10. Cable diameter	0.92D	D
11. Volume resistivity(Ω·m)	1016~1018	1010-1013
12. Tensile strength(Mpa)	23	20
13. Thermal Resistivity   (Deg C/cm/watt)	7.4	730
14. Thermal conductivity(W/m·K)	0.48	0.15
15. Dielectric loss tangent (20℃,60Hz)	0.0002-0.0003	0.04-0.12
16. Elongation (%)	450-600	100-400
17. The breakdown field strength (MV/m)	35-50	20-35
18.Power Factor at 20DegC X1013	-90	80
19. Low Temperature   Brittleness Deg. C	Excellent	-15
20. Moisture Penetration   Resistance	Excellent	Good
21. Water quantity (%)	<0.01	0.8
22. Oxygen index	18	30
23. Toxicity index	1.77	15.01
24. Brittleness temperature℃	-60	-40
25. Softening temperature℃	120	120
26. Resistance to acid and alkali, and climate	best	good ~ best
27. Whether containing halogen	do not contain	containing
28. Moisture Penetration   Resistance	Excellent	Good
29. Oil Resistance	Excellent	Fair
30. Solvent Resistance	Excellent	Poor
31. Acid Resistance	Excellent	Fair
32. Alkali Resistance	Excellent	Good
33. Standard	BS 5467	BS 6346

-> Toxicity index comparison table:

Gas	Gas concentration CQ(ppm)		Dangerous concentrations CQ (ppm)
	Polyvinyl chloride (PVC)	Crosslinked polyethylene (XLPE)
CO	5525	1971	4000
CO2	46300	125400	100000
HCL	6173	0	500
NO2	1.5	3.6	250
SO2	3.25	1.8	400
Toxicity index	15.01	1.77

Summary: cross linked polyethylene insulation cable in the electrical performance, heat resistance, physical and mechanical properties, resistance to climate and toxicity are better than PVC insulated cable.

Reasons Why XLPE is Popular
Here are five reasons why XLPE are popular than standard wires available in the market.

1. Excellent Mechanical and Physical Properties: XLPE has high thermal resistance and higher melting point than most standard cables found in the market. These cables possess low tan delta, high initial dielectric strength, low dielectric strength, and improved mechanical properties at high temperature. Also, XLPE resists moisture, UV light, oxidation, environmental stress, stress cracking, and rupture.
2. Lightweight: The XLPE wire is lighter than other standard wires with a paper or lead insulation. That’s why it is more convenient to install and transport. XLPE wires are largely used in the construction industry because they reduce transportation and installation costs.
3. Easy to Maintain: XLPE wires require lesser maintenance, when compared to other standard cables. Also, they have easy jointing and termination procedures.
4. Used for HT and LT Lines: XLPE wires can be used for both HT and LT lines.
5. Flexibility: XLPE wires have multiple cores, which makes them highly flexible. This added flexibility contributes to smaller bending radius as well.

Recently XLVLDPE (Cross Linked Very Low Density Polyethylene) wires have been introduced to the market.  These wires have enhanced physical and mechanical properties than regular XLPE wires. The above-mentioned factors and XLVLPDE wires depict the rising popularity of XLPE wires in the market.

Benefits of choosing XLPE cable for Fire

Today, we all know the vast range of cables. LT Power Cable, Fire Survival Cable, Submersible flat cable and much more. The names can vary but almost all of these cables have one thing in common. A Conducting metal, an insulation material, and a sheath.

XLPE or better known “Cross-linked Polyethylene” have the feature of excellent insulation.

Basically, it is polyethylene. Polyethylene has crosslink’s which join the individual polymer chains together. Polythene has several applications in the modern world.

However, it has a low melting point.

This low melting point is covered by the cross-linking polymer chains. The cross linking’s helps in increasing the melting point. This and other cross-linked synthetic materials, of which EPR (ethylene propylene rubber) is a notable example, are being increasingly used as cable insulants for a wide range of voltages.

XLPE has many qualities which make it extremely useful for cable insulation. It is flexible permitting smaller bending radius for the cables. It is light weight and water proof. It is also tough which minimizes the need for armoring.

Cross-linking is the effect produced in the vulcanization of rubber and for materials like XLPE the cross-linking process is often described as ‘vulcan- ization’ or ‘curing’. Small amounts of chemical additives to the polymer enable the molecular chains to be cross-linked into a lattice formation by appropriate treatment after extrusion.

It is easier to handle and store compared to cables with paper insulation or lead insulation.

XLPE is considered to be the material of choice due to its ease of processing and handling, although paper / oil systems have a much longer history of usage and much more information on reliability exists.

Benefits of XLPE Cables

1. Electrical and Physical Properties

XLPE cable is known for providing an excellent electrical & physical property. It makes these cables best to use in transmission & distribution lines.

2. It can carry large current

Electricity travels in cables & wires. XLPE cables provide better thermal and aging property.

These special properties make any cable to carry currents under different temperature for long period of time.

3. Ease of Installation

Besides having the ability to stand under different temperature. It is very easy to install too.

As these cables are flexible and light in weight.

4. No need to stress over height and maintenance

Better insulation, better conductive metal provides these types of cable durable and flexible.

Now, it is easy to install these cables anywhere without stressing over height & route issues.

These type of cables do not possess oil, so it needs low maintenance.

5. No Need of Metallic Sheath

Sheath protects cables from external and internal forces at times.

However, In the case of XLPE cables, you need not worry about any metallic sheath or protection.

6. Excellent Protection

An XLPE cable gives an excellent mechanical, electrical, waterproof and radiation resistance.

It is best to use the XLPE insulated cables for electrical connection in line, lead wire of the motor, signal control line, locomotive wire, mining environmental protection cable, subway with shipping, nuclear power laying cable, firing X – ray high voltage line, TV high-voltage wire, and power transmission.

BS 5467 specifies construction and requirements for XLPE and EPR-insulated wire-armoured cables for voltages up to 3.3kV. The construction is basically similar to that of PVC cables to BS 6346, except for the difference in insulant. Because of the increased toughness of XLPE the thicknesses of insulation are slightly reduced compared with PVC.

The standard also covers cables with HEPR (hard ethylene propylene rubber) insulation, but XLPE is the material most commonly used. From 3.8kV up to 33kV, XLPE and EPR insulated cables are covered by BS 6622 which specifies construction, dimensions and requirements.

Conclusion:

Be sure to choose quality products, as choosing quality wires can help in the continuous flow of electricity.

·        Higher Current Rating.

·        High Short Circuit Rating.

·        Longer Service life.

·        For a short time it can withstand maximum 130°C and is favourable to endure short Circuit stresses.

·        It is less sensitive to the setting of the network protection.

·        Because of the thermosetting process taking place due the effect of cross linking, the crack resistance is increased.

·        Due to the chemical cross-linking internal stresses are reduced. Consequently the material is less sensitive during manufacturing process to the setting of the cooling gradient.

·        The thermal resistivity of cross linked material is favorably low, compared to the thermoplastic material.

·        The low dielectric loss is significant advantage.

·        The excellent mechanical features of the insulation improve the protection against external effects.

·        The resistance of the XLPE to acids, alkalies is outstanding and is often compensating the adverse environmental influences.

My recommendation, your application is Low / High always approve XLPE Cable in place of PVC.