Glossary

Phase

Electrical circuits can be single-phase, three-phase or poly-phase depending on the number of source conductors usually lighting and residential circuits are rated single-phase. Single-phase transformers can be used on a three-phase source when two wires of the three-phase system are connected to the primary of the single-phase transformer. Conversely, three single phase sources can be combined to provide three phase power. Typical power distribution networks combine single phase generators to provide three phase distribution voltages.