The pole-mounted distribution transformer (also known as a 'pole pig') has a primary voltage of 12.47 kV (line-line) or 7.2 kV (line-neutral).

[![enter image description here][1]][1]

The secondary voltage supplied to the consumer is 240 V, with an earthed centre tap designated as the neutral.

It's single phase since the line voltages are out-of-phase (180°). 

The voltage between either line and neutral is 120 V.

  [1]: https://i.sstatic.net/ltPXo.png