PCC poles are made by placing high tensile wires in moulds. The wires are stressed by stretching mechanisms which pull the wires apart. When the wires are in this stressed condition, concrete is poured into the mould. After the concrete sets, the wires are released.
A galvanized wire is run through the metal frame to provide for earthing. This wire is connected to the earthing network.
The concrete is thus prestressed. This kind of concrete can withstand impact and has high tensile strength.
PCC poles are more expensive than RCC poles. They are aesthetically pleasing. They can be manufactured at the site itself. This will save transportation costs.