Metering Polyphase Systems – 10 minutes
States the characteristics of delta systems and wye systems. States Blondel’s theorem and describes how it can be applied to meter a three-phase, four-wire wye system, and to a three-phase, three-wire delta system.
Polyphase Meters – 10 minutes
Describes the features of a three-phase, three-wire socket-type meter, and describes how it can be connected to meter a three-phase, three-wire delta system. Describes the features of a three-element meter, and describes how a three-element socket-type meter can be connected to meter a three-phase four-wire wye system.
Balanced and Unbalanced Loads – 11 minutes
Defines balanced load and unbalanced load. Describes how a balanced load and an unbalanced load on a polyphase system can be accurately metered.