Ask Garrie GPT

Copper has superior electrical conductivity. Copper has a lower electrical resistance than aluminum, meaning copper wires can carry electrical current more efficiently and with less energy loss.

Aluminum cables are perfect for service entrance cables, larger-gauge feeder circuits, and overhead power lines. However, modern aluminum cables are also used in general branch circuits in residential applications.

Ampacity is indeed a serious consideration when choosing copper or aluminum because the conductors of aluminum cables are bigger than copper conductors that have the same ampacity. However, there are more considerations. Aluminum has a higher impedance than copper and is lighter and cheaper. As for the benefits of copper, it is more conducive and elastic than aluminum.

AA-8000 aluminum alloy is used for all types of popular aluminum wire, including building wire, per the National Electrical Code. It is considered to be the conventional material for aluminum building wire in the 21st century.

A direct burial cable is an outdoor electrical cable that is buried underground without the conduit. These cables adhere to UL 493, UL 83, UL 854, and other standards.

• USE-2 - service entrance underground transmission cables for underground power lines
• UF-B - direct burial underground feeder cable for residential and commercial purposes
• Aluminum URD Direct Burial Wire - aluminum underground distribution cable double-ranked as USE-2

Common types of cables for residential wiring are:

• NM-B wire for interior wiring
• UF-B wire for outdoor and underground applications
• Metal-clad cables and THHN for attic, basement, or garage

THHN/THWN and XHHW are always used in conduit, including for underground use.

Among the cables popular in households, NM-B wire and MC metal-clad cable are prohibited underground, along with communication cables Cat5, Cat5e, and Cat6 not ranked for direct burial. SOOW and other portable power cords are also not allowed for direct burial or placing in conduit.

Cables that are common for attics are exposed NM-B, THHN and XHHW in conduit, AC cables and MC cables. Portable power cables are not used in the attic. UF-B cables can be used in the attic.

Popular cables with good moisture resistance that make them suitable to install in damp areas are UF-B, USE-2, SOOW, XHHW, THWN-2 (not regular THHN), and any cables with XLPE or EPR insulation.

NM-B, regular THHN, and most communication cables have what can be considered poor moisture resistance.

Some cables that can be submerged in water include submersible pump cables, marine cables, and mining cables. Residential cables are not submerged in water.

Common Uv-resistant cables are THWN-2 cables, solar photovoltaic cables, UF-B cables, direct burial cables, and UV-rated communication cables.

THHN/THWN Wire in conduit is used in hot tubs. NM-B Wire and UF-B wire are never used in hot tubs because the former is an indoor cable, and the latter is the direct burial wire prohibited for hot tubs. Hot tubs only use copper wire, aluminum is not recommended.

6 AWG copper wire is the best choice for a standard hot tub.

XLPE insulation is superior, especially in high-voltage and high-temperature applications, because it has a higher temperature rating and lower dielectric constant. It is also more resistant to abrasion, impact, and chemicals.

• Thermoplastic insulation is made of long-chain polymer molecules that are not cross-linked. Thermoset insulation is made of polymer molecules that are cross-linked or chemically bonded, forming a three-dimensional network.
• Thermoplastic insulation is more susceptible to deformation
• Thermoset has higher tensile strength and chemical resistance.

Common types of thermoset insulation are XLPE, EPR, silicone rubber, and neoprene.

PVC, PE, FEP, Nylon, Teflon, Polypropylene.