METHOD FOR MEASURING ELECTRIC ENERGY AND DEVICE AND INSTRUMENT FOR MEASURING ELECTRIC ENERGY

PROBLEM TO BE SOLVED: To provide a method for measuring electric energy and a device and instrument for measuring electric energy that enables measurement of electric energy using the conventional voltage type, independently of the voltage type of an AC electric circuit and the magnitude of a load current; thus improves the versatility of a single instrument itself and then reduces costs in a supplying manufacturer side; in addition, can easily perform installation and replacement of a watthour meter. SOLUTION: An end of a conductor is connected to each phase including a predetermined reference phase of the AC electric circuit, and a current transformer that mounts a current circuit at a secondary side is installed in a remaining phase except for the reference phase. The other end of a conductor connected the phase with the current transformer is connected to a power source side of the current circuit of the current transformer. After the connection, each of the current circuit is introduced in a single watthour meter together with the conductor of which the end is connected to the reference phase. This method is applied to AC electric circuits, regardless of a single phase and a multiphase, especially an AC electric circuit of a three-wire system or more. COPYRIGHT: (C)2007,JPO&INPIT