Electrical cable basics everyone should know

Electrical cables come in different colours, thickness and are meant to serve a specific purpose. The market is flooded with a wide variety of cables. Understanding the basics of electric cables, therefore, is necessary to identify the right cable for your needs.

  • Cables and Wires: Cables and wires are often synonymous with each other, but there is a significant difference between the two. Cables house two or more than two wires in a single jacket. Wires are either insulated or bare conductors within a jacket.
  • Conduits: Conduits are channels or pipes that wires run through and protect wires against damages. Installing new wires becomes easy with conduits. Plastic PVC conduits are cheaper than their metal counterparts.
  • Wire gauge: Wires have different gauge reading depending upon the amperage of the circuit. 14 gauge and 12 gauge wires are typically meant to be used in residential houses. Home appliances such as dryers, geysers, and electric stove utilize 6 to 10-gauge wire.
  • Numbers on electric cables: Electric cables have numbers separated by a hyphen. The first number represents the conductor's gauge, and the number after the hyphen indicate the number of conductors housed within the cable.  Conductors are color-coded denoting specific purpose in the circuit.
  • Colour Coding on Cables' Outer Sheath: The gauge of the wire can be known by looking at the colour coding on cables' outer sheath.
  1. White Colour: White colour indicates 14-gauge wire and 15-amp circuit
  2. Yellow Colour: Yellow colour refers to 12-gauge wire and 20-amp circuit
  3. Orange Colour: Orange colour refers to 10-gauge wire and 30-amp circuit
  4. Black Colour: Black colour refers to 8- or 6-gauge wire, 45- or 60-amp circuits
  5. Gray Colour: Grey colour is for underground cables. The sheath labelling of underground feeder indicates details about gauge and amperage for the circuit.
  • Colour coding of wires: Wire colour coding is standard for all conductors.
  1. Blue/ Red: Blue or Red coloured wires are hot wires responsible for conduction of current from panels to devices such as switches, electrical appliance, etc.
  2. White: White coloured wires are neutral and conduct current back to the panel so that circuit is complete.
  3. Green: Green coloured wires facilitate a path for the fault current to return to the panel by breaking the fuse whenever a ground fault occurs.
  • Metal-clad cable(MC): Metal clad cables are generally used for feeders and branch circuits in various applications
  • Non-metallic cable(NM): It is also called NM cable and has an outer plastic coating. The non-metallic layer houses the flexible electrical cable in it. It is used mostly in residential wiring.