Phase Wire

The ‘live’ or ‘hot’ wire. 

Phase cable colors are ‘red’ or ‘brown’ for single phase.

For three-phase, the color code could be either ‘red’, ‘white’ and ‘blue’ or ‘brown’, ‘blue’, and ‘black’. (ASNZS:3000:2007 – section 3)

The phase terminal is indicated by a ‘L’, ‘L/+’, ‘P’ lettering for single phase and ‘L1’, ‘L2’, ‘L3’ for three phase power. 

Voltages in single-phase are 230 volts between phase and earth and 230 volts between phase and neutral.

In three-phase, voltages are 400 volts between each phase, 230 volts phase to earth and 230 volts phase to neutral.

The phase voltage works by alternating from zero volts to peak voltage to zero to peak to zero. This cycle occurs 50 times per second or once per 0.02 seconds (50Hz).

For the USA, this occurs 60 times per second (60Hz).