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.
| Y | Yw | Yw | Yk | ||
|---|---|---|---|---|---|
| PVC | PVC | PVC | PVC | ||
| Polyvinylchloride | Heat-resistant | Heat-resistant | Cold | ||
| 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 | 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 | Medium | Medium | Medium | |
| Cold Resistance | Moderate - Good | Moderate - Good | Moderate - Good | Very Good | |
| 2Y | 2Y | 2X | O2Y | ||
|---|---|---|---|---|---|
| LDPE | HDPE | VPE |
| ||
| Low density | High density | Cross Linked | Foamed | ||
| 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 | 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 | Medium | Good | - | |
| Cold Resistance | Good | Good | Good | Good | |
| 3Y | 4Y | 9Y | 11Y | TPE-E (12Y) | TPE-O | ||
|---|---|---|---|---|---|---|---|
| PS | PA | PP | PUR |
|
| ||
| Polystrole | Polyamide | Poly-propylene | Poly-urethane | PolYester | Polyolefine | ||
| 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 | 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 | 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 | |
| G | 2G | 3G | 4G | 5G | 6G | ||
|---|---|---|---|---|---|---|---|
| NR | SiR | EPR | EVA | CR | CSM | ||
| Natural Rubber | Silicone Rubber | Ethylen- | Ethylene- | Poly- | Chloro- | ||
| 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 | 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 | Self | |
| 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 | |
| 10Y | 7Y | 6Y | 5YX | 5Y | ||
|---|---|---|---|---|---|---|
| PVDF | ETFE | FEP | PFA | PTFE | ||
| Polyvinylidene | Ethylene-
| Fluorine Ethylene | Perfluoral- | Poly- | ||
| 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 | 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 | Self | Self | Self | Self | |
| 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 | |
| H | HX | ||
|---|---|---|---|
| Not Cross Linked | Cross Linked | ||
| Halogen Free | Halogen Free | ||
| 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 | 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: | Medium in Black: | |
| Cold Resistance | Average | Average | |
Thermoplastic and Thermosetting - myElectrical note comparing these types of insulation