Live Conductor: Definition, Meaning, Examples

Live conductor: a conductor intended to be energized in normal use, including a neutral conductor but, by convention, not a PEN conductor [defined in the BS7671].

Examples

The term “live conductor” is derived from the general term “live part” and refers to those live conductive parts intended to conduct certain electric currents.

Live conductors are primarily defined as phase conductors and pole conductors, which under normal conditions are energized in a way that poses a serious hazard to humans and animals. The neutral conductor and the mid-point conductor, which are under low voltage, are also live conductors. Phase and pole conductors in ultra-low voltage electrical circuits have a voltage that are generally not hazardous to humans and animals.

Figure 1 shows phase conductors L1, L2, L3 and neutral conductor N, which are examples of live conductors.

TN-S system 3-phase, 4-wire with separate the neutral conductor and the protective conductor throughout the distribution system
Figure 1 – TN-S system 3-phase, 4-wire with separate the neutral conductor and the protective conductor throughout the distribution system [2]

I will also give examples of conductors that are not classified as live conductors:

Protective conductors are not live under normal conditions. Therefore they are not live conductors. PEN-, PEM– and PEL-conductors firstly act as protective conductors. Therefore, even though, secondly, they serve as neutral, mid-point and line conductors, they are not generally regarded as live conductors.

In Figure 1, you can see the protective conductor PE, which is not classified as a live conductor.

References

  1. BS7671
  2. IEC 60364-1