CURRENT MEASURING INSTRUMENT

PROBLEM TO BE SOLVED: To provide a current measuring instrument capable of measuring the current of each phase flowing to a cable when batch-clamping a three-phase cable by a clamp CT to know whether the current can be cut off by confirming the magnitude of a load current when going to cut off an electric circuit by a disconnecting switch because arc is generated to inhibit cut-off in the flowing state of the load current in the disconnecting switch although the disconnecting switch is used for cutting off a power receiving facility from the electric circuit in maintenance and inspection of the high voltage power receiving facility and also because load equipment such as a circuit breaker or a transformer is distant from the disconnecting switch in many cases in a building. SOLUTION: A large number of independent coils are wound along an annular magnetic path using an air-cored bobbin, and induced voltage of each coil is measured to compute the magnitude of the load current from a mean value and a maximum value. COPYRIGHT: (C)2009,JPO&INPIT