Electric Wiring, 3rd Edition

6 Wiring circuits simply explained

Power transformers are more efficient if the load on each phase is

approximately the same and, therefore, single-phase services are normally

connected to alternate phases and three-phase consumers are encouraged to

balance their loads over the three phases.

The local boards provide underground-cable or overhead-line

services which terminate at a convenient point within the premises. Overhead

services are terminated on a bracket high up on a wall of the property and

insulated leads taken through the wall to the meter position. Underground

services are usually brought through below floor level via a duct. Th ...