There are as many different types of specialized electrical wire and cable insulation materials as there are wire and cable types. A good electrical insulator will not only protect the wire or cable underneath, but it will also prevent the loss of electrical potential and help reduce the risk of fire and electric shock.

Just as there are specialty types of wire and cable like marine electrical wire or welding cable, there are many different types of electrical wire insulation. This short post will cover some of the most common types of electrical wire insulators.

Nylon

Nylon is a low-cost, highly durable synthetic material that is commonly used as an electrical wire insulator. Like other good insulators, nylon does not readily conduct electricity, but on top of that, it is highly durable and abrasion resistant. It also offers a fair degree of chemical resistance, too.

A common type of nylon insulation is THHN, or “thermoplastic, high-heat nylon” that is resistant to high temperatures. While nylon itself is not flame resistant, THHN is designed to resist high temperatures.

Nylon is also highly flexible, even in the cold, which makes it suitable for use in some exposed locations. One drawback however, is that nylon can potentially absorb moisture, which is a detriment in humid and wet locations.

PVC

PVC, known more properly as polyvinyl chloride, is another suitable material for electrical wire and cable insulation. This is another low-cost material that is popular as a result for electrical insulation.

PVC offers a wide variety of beneficial physical characteristics; among these are high resistance to abrasion, as well as to sunlight, weather, acids and oils.

PVC is also inherently flame-retardant, which makes it popular among electronic insulation, as well as for use in fire alarm cable insulation, although when used there, special designations apply.

PE

Polyethylene, also known as PE, is the most commonly produced plastic in the world. It is low in cost and offers a variety of beneficial characteristics that make it suitable in some applications as an electrical insulator.

While PE itself is not highly resistant to UV degradation, a special type of PE, known as CPE, or chlorinated polyethylene (and another type called XLPE, or cross-linked polyethylene), is resistant to UV as well as ozone. Appropriate grades of PE can offer excellent resistance to moisture absorption, acids, solvents, and other chemicals.

CPE, specifically, also offers excellent abrasion resistance as well; this, paired with its outstanding resistance to moisture absorption and abrasion make it suitable for use in certain direct burial applications.

PUR

PUR is polyurethane, another low-cost thermoplastic that is commonly used as an electrical insulator due to a combination of low-cost, ready availability and general suitability.

Some of polyurethane’s strengths include high heat resistance, low temperature flexibility, and high oxidation resistance. One of its strongest redeeming qualities is that it offers excellent physical durability and abrasion resistance.

However, there are a few drawbacks associated with polyurethane; it offers poor flame and moisture resistance.

EPR and EPDM

EPR, or ethylene propylene rubber, along with EPDM, or ethylene propylene diene monomer, are both forms of synthetic rubber that offer some of the best traits out there for electrical insulation applications.

EPR offers excellent oxidation and abrasion resistance, as well as high heat resistance; it is also flexible at very cold temperatures, which makes it desirable for many outdoor applications, such as solar panel cable or flexible welding cable.

EPR and EPDM both offer excellent resistance to sunlight and weathering, another attribute that makes them attractive as solar panel cable.

Neoprene

One more type of synthetic insulation used in electrical wire and cable is neoprene, a highly flexible thermoset that does not get brittle at cold temperatures or deform at high temperatures. Neoprene also offers high resistance to weathering, oxidation and sunlight.

This makes neoprene a niche insulation material sometimes used in very demanding environments, such as industrial applications, in agriculture, mining, and even dredging.

Desirable Quality in Electrical Wire and Cable Jacket Insulation Materials

While the specific desirable attributes of electrical wire and cable insulation are determined by application, here are a few things that are nearly universally desirable:

• Low propensity to conduct electricity
• General physical durability and abrasion resistance
• Chemical stability
• UV, ozone and weathering resistance
• Low moisture absorption capacity (as in the case of marine electrical wire, where moisture absorption would accelerate corrosion)
• High flexibility at low temperatures (desirable for cables that must remain flexible, such as marine electrical wire and welding cable)
• High resistance to heat, or flame retardance (desirable in fire alarm cables)
• Resistance to deformation as a result of heat, aging or chemical attack

Questions About Electrical Wire and Cable? Contact Us 

Still have specific questions about wire insulation or about a specific specialized type of electrical wire, like marine grade battery wire or aluminum triplex wire? Get in touch with us at Sales@EWCSWire.com and we will be more than happy to help.