Street and area lighting looks like a small load, a few hundred watts per pole, yet the cable that feeds it is rarely small. The feeders are long, they run outdoors and underground, and they tap off at many points, so the choice of cable and the way it is sized differ from indoor wiring.
Underground runs
The usual underground choice is an armoured LV XLPE power cable. It is rated for direct burial or for laying in ducts, the armour gives mechanical protection and an earth path, and XLPE insulation tolerates the load and the ground temperature. Because a lighting feeder may run a long way before the last pole, voltage drop, rather than the current itself, tends to decide the conductor size. A cable large enough to carry the current can still leave the far poles dim, so the run length is checked before the size is fixed.
Overhead runs
Where the distribution is overhead, aerial bunched cable is the modern choice. Insulated cores are twisted around a bare messenger that carries the mechanical load, which resists illegal tapping, abrasion and contact with trees far better than bare open wires. It is quicker to string and safer to live near.
Points to get right
Both types must be rated for outdoor service, the armour or messenger has to be earthed at the specified points, and feeder pillars, joints and pole terminations are matched to the cable and sealed against water. APAR supplies LV XLPE power cables for buried lighting feeders and aerial bunched cables for overhead lighting distribution.