Cable Insulation Properties 

By on May 15th, 2012

HDPECableInsulationResin_2
HDPE Cable Insulation
Resin

Cable insulation is used to provide electrical separation between conductors of a cable. During the historical development of cables, numerous types of insulation have been employed. During recent years, there has been some consolidation in the types of insulation used.

This post provides some information on the more commonly used cable insulation materials.

Insulation Materials (PVC)

Y

Yw

Yw

Yk

PVC

PVC

PVC

PVC

Polyvinylchloride
Compounds

Heat-resistant
90oC

Heat-resistant
105oC

Cold
Resistant

Density g/cm3

1.35 - 1.5

1.3-1.5

1.3-1.5

1.2-1.

Breakdown Voltage KV/mm (20oC)

25

25

25

25

Specific Volume Resistivity Ω cm (20oC)

1013-1015

1012-1015

1012-1015

1012-1015

Dielectric Constant 50 Hz (20oC)

3.6-6

4-6.5

4.5-6.5

4.5-6.5

Dielectric Loss Factor (tan δ)

4 x 10-2 to 1 x 10-1

4 x 10-2 to 1 x 10-1

4 x 10-2 to 1 x 10-1

4 x 10-2 to 1 x 10-1

Working
Temperature

Permanent oC

-30 +70

-20 +90

-20 +105

-40 +70

Short Time oC

+100

+120

+120

+100

Melt  Temperature +oC

>140

>140

>140

>140

Flame Resistance

Self Extinguishing

Self Extinguishing

Self Extinguishing

Self Extinguishing

Oxygen Index LOI (% O2)

23-42

23-42

24-42

24-42

Heating Value H0 MJ.kg-1

17-25

16-22

16-20

17-24

Thermal Conductivity W.K-1.m-1

0.17

0.17

0.17

0.17

Corrosive Gases In Case Of Fire

Hydrogen Chloride

Hydrogen Chloride

Hydrogen Chloride

Hydrogen Chloride

Radiation Resistance max Mrad

80

80

80

80

Tensile Strength N/mm2

10-25

10-25

10-25

10-25

Elongation At Break %

130-350

130-350

130-350

130-350

Shore Hardness

70-95 (A)

70-95 (A)

70-95 (A)

70-95 (A)

Abrasion Resistance

Medium

Medium

Medium

Medium

Water Absorption %

0.4

0.4

0.4

0.4

Halogen Free

No

No

No

No

Weather Resistance

Medium
(Black: Good)

Medium
(Black: Good)

Medium
(Black: Good)

Medium
(Black: Good)

Cold Resistance

Moderate - Good

Moderate - Good

Moderate - Good

Very  Good

 

Insulation Materials (PE)

2Y

2Y

2X

O2Y

LDPE

HDPE

VPE

 

Low density
Polyethylene

High density
Polyethylene

Cross Linked
Polyethylene

Foamed
Polyethylene

Density g/cm3

0.92-0.94

0.94-0.98

0.92

≈0.65

Breakdown Voltage KV/mm (20oC)

70

85

50

30

Specific Volume Resistivity Ω cm (20oC)

1017

1017

1012-1016

1017

Dielectric Constant 50 Hz (20oC)

2.3

2.3

4-6

≈1.55

Dielectric Loss Factor (tan δ)

2 x 10-4

3 x 10-4

2x 10-3

5 x 10-4

Working
Temperature

Permanent oC

-50 +70

-50 +00

-35 +90

-40 +70

Short Time oC

+100

+120

+100

+100

Melt  Temperature +oC

105-110

130

-

105

Flame Resistance

Flammable

Flammable

Flammable

Flammable

Oxygen Index LOI (% O2)

≤22

≤22

≤22

18-30

Heating Value H0 MJ.kg-1

42-44

42-44

42-44

42-44

Thermal Conductivity W.K-1.m-1

0.3

0.4

0.3

0.25

Corrosive Gases In Case Of Fire

No

No

No

No

Radiation Resistance max Mrad

100

100

100

100

Tensile Strength N/mm2

10-20

20-30

12.5-20

8-12

Elongation At Break %

400-600

500-1000

300-400

350-450

Shore Hardness

43-50 (D)

60-63 (D)

40-45 (D)

-

Abrasion Resistance

Medium

Good

Medium

-

Water Absorption %

0.1

0.1

0.1

-

Halogen Free

Yes

Yes

Yes

Conditional

Weather Resistance

Medium
(Black: Good)

Medium
(Black: Good)

Good

-

Cold Resistance

Good

Good

Good

Good

 

Insulation Materials (other)

3Y

4Y

9Y

11Y

TPE-E (12Y)

TPE-O

PS

PA

PP

PUR

 

 

Polystrole

Polyamide

Poly-propylene

Poly-urethane

PolYester
Elastomer

Polyolefine
Elastomer

Density g/cm3

1.05

1.02-1.1

0.91

1.15-1.2

1.2-1.4

0.89-1.0

Breakdown Voltage KV/mm (20oC)

30

30

75

20

40

30

Specific Volume Resistivity Ω cm (20oC)

1016

1015

1016

1010-1012

>1010

>1014

Dielectric Constant 50 Hz (20oC)

2.5

4

2.3-2.4

4-7

3.7-5.1

2.7-3.6

Dielectric Loss Factor (tan δ)

1 x 10-4

2 x 10-2 to 1 x 10-3

4 x 10-4

2.3 x 10-2

1.8 x 10-2

1.8 x 10-2

Working
Temperature

Permanent oC

-50 +80

-60 +05

-10 +100

-55 +80

-50 +100

-50 +100

Short Time oC

+100

+125

+140

+100

+140

+130

Melt  Temperature +oC

>120

210

160

150

190

150

Flame Resistance

Flammable

Flammable

Flammable

Flammable

Flammable

Flammable

Oxygen Index LOI (% O2)

≤22

≤22

≤22

≤22

≤29

≤25

Heating Value H0 MJ.kg-1

40-43

27-31

42-44

20-26

20-25

23-28

Thermal Conductivity W.K-1.m-1

0.25

0.23

0.19

0.25

0.5

1.5

Corrosive Gases In Case Of Fire

No

No

No

No

No

No

Radiation Resistance max Mrad

80

10

10

100 (500)

10

10

Tensile Strength N/mm2

55-65

50-60

20-35

30-45

30

20

Elongation At Break %

300-400

50-170

300

500-700

>300

>300

Shore Hardness

35-50 (D)

-

55-60 (D)

70-100 (A)

85 (A), 70 (D)

55 (A), 70 (D)

Abrasion Resistance

Good

Very Good

Medium

Very Good

Good

Good

Water Absorption %

0.4

1.0-1.5

0.1

1.5

1.5

1.5

Halogen Free

Yes

Yes

Yes

Yes

Yes

Yes

Weather Resistance

Medium - Good

Good

Moderate

Very Good

Very Good

Very Good

Cold Resistance

Moderate - Good

Good

Good

Very Good

Very Good

Very Good

 

Elastomere Materials

G

2G

3G

4G

5G

6G

NR
SBR

SiR

EPR

EVA

CR

CSM

Natural Rubber
Styrol-
Butadiene Rubber
Compounds

Silicone Rubber

Ethylen-
Propylene

Rubber
Compounds

Ethylene-
Vinylacetate

Copolymere
Compounds

Poly-
Chloroprene

Compounds

Chloro-
Sulfonated

Polyethylene
Compounds

Density g/cm3

1.5-1.7

1.2-1.3

1.3-1.55

1.3-1.5

1.4-1.65

1.3-1.6

Breakdown Voltage KV/mm (20oC)

20

20

20

30

20

25

Specific Volume Resistivity Ω cm (20oC)

1012-1015

1015

1014

1012

1010

1012

Dielectric Constant 50 Hz (20oC)

3-5

3-4

3-3.8

5-6.5

6-8.5

6-9

Dielectric Loss Factor (tan δ)

1.9 x 10-2

6x 10-3

3.4 x 10-3

2 x 10-2

5 x 10-2

2.8 x 10-2

Working
Temperature

Permanent oC

-65 +60

-60 +180

-30 +90

-30 +125

-40 +100

-30 +80

Short Time oC

+120

+260

+160

+200

+140

+140

Melt  Temperature +oC

-

-

-

-

-

+160

Flame Resistance

Flammable

High Flash Point

Flammable

Flammable

Self
Extinguishing

Self
Extinguishing

Oxygen Index LOI (% O2)

≤22

25-35

≤22

≤22

30-35

30-35

Heating Value H0 MJ.kg-1

21-25

17-19

21-25

19-23

14-19

19-23

Thermal Conductivity W.K-1.m-1

-

0.22

-

-

-

-

Corrosive Gases In Case Of Fire

No

No

No

No

Hydrogen Chloride

Hydrogen Chloride

Radiation Resistance max Mrad

100

50

200

100

50

50

Tensile Strength N/mm2

5-10

5-10

5-10

8-12

10-20

10-20

Elongation At Break %

300-600

300-600

200-400

250-350

400-700

350-600

Shore Hardness

60-70 (A)

40-80 (A)

65-85 (A)

70-80 (A)

55-70 (A)

60-70 (A)

Abrasion Resistance

Moderate

Moderate

Moderate

Moderate

Medium

Medium

Water Absorption %

1.0

1.0

1.0

1.0

1.0

1.5

Halogen Free

No

Yes

Yes

Yes

No

No

Weather Resistance

Moderate

Good

Very Good

Good

Very Good

Very Good

Cold Resistance

Very Good

Very Good

Good

Good

Moderate

Moderate

 

High Temperature Materials

10Y

7Y

6Y

5YX

5Y

PVDF

ETFE

FEP

PFA

PTFE

Polyvinylidene
Fluoride
Kynar/Dyflor

Ethylene-
Tetrafluorethylene

 

Fluorine Ethylene
Propylene

Perfluoral-
Koxypolymeric

Poly-
Tetrafluorethylene

Density g/cm3

1.7-1.9

1.6-1.8

2.0-2.3

2.0-2.3

2.0-2.3

Breakdown Voltage KV/mm (20oC)

25

36

25

25

20

Specific Volume Resistivity Ω cm (20oC)

1014

1016

1018

1018

1018

Dielectric Constant 50 Hz (20oC)

9-7

2.6

2.1

2.1

2.1

Dielectric Loss Factor (tan δ)

1.4 x 10-2

8 x 10-4

3 x 10-4

3 x 10-4

3 x 10-4

Working
Temperature

Permanent oC

-40 +135

-100 +150

-100 +205

-190 +260

-190 +260

Short Time oC

+160

+180

+230

+280

+300

Melt  Temperature +oC

>170

>265

>225

>290

>325

Flame Resistance

Self
Extinguishing

Self
Extinguishing

Self
Extinguishing

Self
Extinguishing

Self
Extinguishing

Oxygen Index LOI (% O2)

40-45

30-35

>95

>95

>95

Heating Value H0 MJ.kg-1

15

14

5

5

5

Thermal Conductivity W.K-1.m-1

0.17

0.24

0.26

0.21

0.26

Corrosive Gases In Case Of Fire

Hydrofluoric

Yes

Yes

Yes

Yes

Radiation Resistance max Mrad

10

10

1

0.1

0.1

Tensile Strength N/mm2

50-80

40-50

15-25

25-30

80

Elongation At Break %

150

150

250

250

50

Shore Hardness

75-80 (D)

70-75 (D)

55-60 (D)

55-60 (D)

55-60 (D)

Abrasion Resistance

Very Good

Very Good

Very Good

Very Good

Very Good

Water Absorption %

0.01

0.02

0.01

0.01

0.01

Halogen Free

No

No

No

No

No

Weather Resistance

Very Good

Very Good

Very Good

Very Good

Very Good

Cold Resistance

Very Good

Very Good

Very Good

Very Good

Very Good

 

Halogen Free Compounds

H

HX

Not Cross Linked

Cross Linked

Halogen Free
Polymer Compounds

Halogen Free
Polymer Compounds

Density g/cm3

1.4-1.6

1.4-1.6

Breakdown Voltage KV/mm (20oC)

25

25

Specific Volume Resistivity Ω cm (20oC)

1012-1014

1013-1014

Dielectric Constant 50 Hz (20oC)

3.4-5

3.4-5

Dielectric Loss Factor (tan δ)

~10-3

10-2-10-3

Working
Temperature

Permanent oC

-30 +70

-30 +90

Short Time oC

+100

+150

Melt  Temperature +oC

>130

-

Flame Resistance

Self Extinguishing

Self Extinguishing

Oxygen Index LOI (% O2)

≤40

≤40

Heating Value H0 MJ.kg-1

17-22

16-25

Thermal Conductivity W.K-1.m-1

0.17

0.20

Corrosive Gases In Case Of Fire

No

No

Radiation Resistance max Mrad

100

200

Tensile Strength N/mm2

8-13

8-13

Elongation At Break %

150-250

150-250

Shore Hardness

65-95 (A)

65-95 (A)

Abrasion Resistance

Medium

Medium

Water Absorption %

0.2-1.5

0.2-1.5

Halogen Free

Yes

Yes

Weather Resistance

Medium in Black:
Good

Medium in Black:
Good

Cold Resistance

Average

Average

See Also

Thermoplastic and Thermosetting  - myElectrical note comparing these types of insulation



Steven McFadyen's avatar Steven McFadyen

Steven has over twenty five years experience working on some of the largest construction projects. He has a deep technical understanding of electrical engineering and is keen to share this knowledge. About the author


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  1. Notes's avatar Notes says:
    2/1/2013 5:30 AM

    Trackback from Notes

    IEC 60287 "Calculation of the continuous current rating of cables (100% load factor)" is the International Standard which defines the procedures and equations to be used in determining the current carry capacity of cable. The standard is applicable... ...


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