Question

name four types of material for making cable insulation and their typical applications in electrical services.which cable insulation given has the highest permissible operating temperature

Answer 1

There are many types of material for making cable insulation and it have many advantages and disadvantages

Plastics

Polyvinyl Chloride (PVC):- A PVC jacket is a relatively inexpensive and easy-to-use material, with the potential to be used in diverse applications. The maximum temperature range is -55°C to 105°C and is flame, moisture, and abrasion resistant. It also holds up against gasoline, ozone, acids, and solvents.

Semi-Rigid PVC (SR-PVC)
This is mainly used as a primary insulation and is very abrasion resistant. Semi-Rigid PVC is also heat, water, acid, and alkali resistant, as well as flame retardant.

Plenum Polyvinyl Chloride (Plenum PVC)
Plenum PVC is suitable for use in building spaces behind dropped ceilings or raised floors which are left open to allow for air circulation. Standard PVC is considered a non-plenum insulation option because it does not exhibit the qualities necessary for safe usage in plenum areas. To be plenum-rated the insulation must meet more stringent fire safety regulations.

Polyethylene (PE)
This compound is used most in coaxial and low capacitance cables because of its exemplary electric qualities. Many times it is used in these applications because it is affordable and can be foamed to reduce the dielectric constant to 1.50, making it an attractive option for cables requiring high-speed transmission. Polyethylene can also be cross-linked to produce high resistance to cracking, cut-through, soldering, and solvents. Polyethylene can be used in temperatures ranging from -65°C to 80°C.

Polypropylene (PP)
This material is very similar to Polyethylene, but has a wider temperature range of -30°C to 105°C. It is used primarily for thin wall primary insulations. Polypropylene can be foamed to improve its electrical properties.

Polyurethane (PUR)
Polyurethane is known for its extreme toughness, flexibility, and flex life, even in low temperatures. It also has excellent ratings for chemical, water, and abrasion resistance.
Nylon
Nylon is usually extruded over softer insulation compounds. It serves as a tough jacket, exhibiting strong abrasion, cut-through, and chemical resistance, especially in thin wall applications. It is also extremely flexible. One disadvantage of Nylon is its absorption of moisture which degrades some of its electrical properties.

Rubbers:-

Thermoplastic Rubber (TPR)
In many applications, TPR is used to replace true thermoset rubber. It has improved colorability, higher processing speeds, and a wider usable temperature range. It also displays excellent heat, weather, and age resistance without curing. TPR is not cut-through resistant, but can be used in applications where other properties of rubber are preferred.

Neoprene (Polychloroprene)
This is a synthetic thermoset rubber that must be vulcanized to obtain its desired qualities. It exhibits supreme abrasion, cut-through, oil, and solvent resistance. Neoprene is also known for its long service life and wide ranges of temperature and usability. It is remarkably flame retardant and self-extinguishing. >Military products often incorporate Neoprene. This material is especially desirable for hand-held cordsets.

Styrene Butadiene Rubber (SBR)
This is a thermoset compound with qualities similar to Neoprene. It has a temperature range of -55°C to 90°C. SBR is primarily used in Mil-C-55668 cables.

Silicone
This material is extremely heat resistant and flame retardant and can be used in temperatures up to 180°C. It is moderately abrasion resistant. Silicone is also extremely flexible. Benefits include a long storage life and good bonding properties necessary in many electrical applications.

Fiberglass
Fiberglass is the most widely used glass insulation. It can be used continuously in temperatures up to 482°C. This material is moisture and chemical resistant, but only fairly abrasion resistant. Its common applications include heat treating, glass and ceramic kilns, foundries, and extensive applications in aluminum processing.

Fiberglass is the most widely used glass insulation. It can be used continuously in temperatures up to 482°C.fiber glass is used cable insulation given has the highest permissible operating temperature