The type of cable used for sockets in residential and commercial wiring depends on many factors, which are briefly introduced below.
Types of cables commonly used for sockets
1. Non-metallic sheathed cable (NM cable, twin and earth cable)
NM-B, NM-C, NMD90, twin and earth cable, the conductor is copper conductor, PVC sheath, rated temperature 90°C, commonly used for indoor residential wiring.
2. Metal-clad cable (MC cable), the conductor is copper conductor, PVC insulation, flexible metal (steel or aluminum) sheath, rated temperature 90°C, commonly used in areas where the cable may be physically damaged; the use of metal sheath provides additional protection.
3. Underground feeder cable (UF cable), the conductor is copper conductor, solid thermoplastic material sheath, rated temperature 90°C, suitable for direct burial and wet locations; used for outdoor sockets and underground installations.
4. Thermoplastic High Heat Nylon Coated (THHN) wire, copper conductor, PVC insulation, nylon coated thermoplastic insulation jacket, rated at 90°C, conduit for general purpose wiring.
Specifications of socket cables
The gauge of the wire determines its current carrying capacity. Common gauges for socket wiring are 1.5mm to 2.5mm.
Choosing the amperage of the socket cable
The cable can handle the expected load. For a standard household socket, this is usually 15-20 amps.