Electrical wiring is vital to the power distribution of any building or structure. To cater to the powering needs of a building, a wide range of wires and cables are available to connect g central power sources, lights, and other appliances used for power distribution.

With the variety of wires and cables available for different uses, it's essential to understand the specifications and applications of each. The growth in the number of construction and electrical projects has driven the increased demand for these specialized materials. The global wire and cable market stood at $201 billion in 2024 with a projected growth of $266.2 billion by 2029 with a CAGR of 5.8%.

Selecting the right type of wire, suited to the needs of your residential project is essential. This blog delves deeper into the various types of wires suited to the needs of different types of residential buildings and structures.

NM Cable (Non-Metallic Cable)

NM cables known as Romex wires, are non-metallic wires with two or more hot conductors and one grounding insulator. The conductors are wrapped together in a plastic sheath.

They are suitable for indoor wiring applications like switches, power outlets, and light fixtures.

NM cables are preferred in dry locations because they are insulated with a protective plastic sheath that is not designed to withstand moisture. They are also color-coded to depict the type of wiring gauge. For instance, 14-gauge for 15-amp circuits are white, and 12-gauge for 20-amp circuits are yellow.

These cables are popular in homes for various reasons including the versatility of use and ease of installation. The most common NM Cables used at homes include -

• 8-gauge wire:

  • Ampacity: Suitable for 40-amp circuits.

  • Sheathing Color: Comes with black sheathing.

• 10-gauge wire:

  • Ampacity: Rated for 30-amp circuits.

  • Sheathing Color: Comes with orange sheathing.

• 12-gauge wire:

  • Ampacity: Designed for 20-amp circuits.

  • Sheathing Color: Comes with yellow sheathing.

• 14-gauge wire:

  • Ampacity: Intended for 15-amp circuits.

  • Sheathing Color: Comes with white sheathing.

Conduit Wiring ( PVC or Metal )

Conduit wiring is a method of electrical installation of wires to enclose them within protective piping layers known as conduits. The protective pipe safeguards the wires from damage, environmental hazards, and moisture. They are used in residential settings due to their flexibility and durability. Various types of conduit wirings include surface and concealed conduit wirings. Surface conduit wirings are directly mounted to the surface of walls and ceilings, and used to power residential lighting circuits throughout homes, electrical outlets in living spaces, kitchens, and bathrooms. Concealed conduit wiring involves electrical cables within conduits hidden behind walls, ceilings, or floors. Concealing the wires helps in enhancing the aesthetics of a building.

Casing and Capping Wiring

Casing and capping are different types of wirings that involve encasing insulated wires within protective pipes known as conduits to safeguard from physical damage. Casing is a traditional method involving encasing insulated wires within a cap. This is suited for low-voltage applications in residential and commercial settings. These wires can further be classified in two ways -

Press and Fit is one of the most common types of Casing and Capping, where the bottom portion is fastened to the wall first, followed by feeding the wiring and pressing the cover into place.

Wooden Casing is traditionally made from seasoned wood, this type uses grooves to hold the wires securely. It is less commonly used today, due to advancements in materials.

Twin and Earth Wiring

Twin and Earth wiring (T&E wiring) is used in fixed installations and is known for its simplicity in design, installation, and maintenance. In its design, two current-carrying insulated conductors with an uninsulated conductor are attached to the ground. These conductors are generally made of copper with PVC insulation. The uninsulated, protective layer provides grounding to ensure safety. Made of PVC or thermoplastic material, the sheathing layer protects the inner conductor from unfavorable environmental conditions such as UV rays. In domestic settings, they are used in lights, switches, and power outlets for televisions, computers, and kitchen appliances. Ideal for connecting fixed devices and appliances, they are used in ovens, washing machines, and hobs.

Armored Cable (BX)

Armored cables are also known as BX cables, they come with a protective metal armor. It consists of flexible, galvanized steel that provides physical protection and durability for electrical installations. The armor is designed with wound steel strips for increased durability, flexibility, and strength. These cables are suited for areas requiring extra protection such as basements or garages. They are also used in heavy-duty appliances like air conditioners, washing machines, and water heaters, where enhanced safety and durability are crucial.

Low-Voltage Wiring

Low voltage wirings operate below 50 Volts. Apart from other uses, they are used in landscape lighting and security systems. Low-voltage wiring is also used in various modern-day home appliances including doorbells, smart TVs, and networking devices like Wifi routers, ethernets, and sensors. Lower voltage levels reduce the risk of electrical shocks and fires, making it a safer choice for residential wiring. Low-voltage wiring is cost-efficient, versatile, and environmentally friendly.

THHN/THWN Wire

Thermoplastic High Heat-resistant Nylon-coated and Thermoplastic Heat (THHN) and Water-resistant Nylon-coated (THWN) wires are commonly used in residential buildings, due to their durability and versatility, power distribution. They are made with thermoplastic PVC insulation and nylon coating. They are rated for a maximum of 90°C (194°F) in dry conditions and 75°C (167°F) in wet environments. In THWN Wire, they are rated for 90°C (194°F) in both dry and wet conditions. T

They are used for power distribution in lights, switches, and outlets throughout the home and appliance wirings such as refrigerators, ovens, and air conditioners. They are suitable to use in dry and damp conditions making them versatile for different areas around the house and they have effective grounding systems to provide safety against electrical shock.

Conclusion

The choice of wires depends on the requirements of a particular residential or building project. Different aspects of wires and cables including conductibility, insulation, grounding, and the engineering of the wires make them suitable for appliances with varied voltage, temperature, and moisture. These factors must be considered when choosing the right wires from a range of options available. Choose the perfect wires for your project with Headsup B2B, your trusted partner in sourcing high-quality, reliable solutions—contact us today to streamline your wiring needs.