PURPOSE: To detect the fault of the connection of a watt-hour meter to a metering terminal apparatus at an early stage by informing the fact when the integrated consumption within a prescribed time is outside a prescribed range during the operation of a load device.
CONSTITUTION: When a load device 4 is operated, a watt-hour meter 3 detects a power consumption so as to output a pulse signal to a pulse input means 5a at a metering terminal apparatus 5. Then, the number of pulses in a pulse signal to be output by the means 5a is integrated by an integrating means 5b and by a abnormality warning means 5d. In addition, the means 5d investigates a timer 5g during the operation of the device 4 on the basis of information from an operation detection means 5e. When a prescribed time has elapsed, an integrated value, for abnormality information, which has been integrated 5d during the prescribed time is compared with the number of upper-limit pulses and that of lower-limit pulses. When the integrated value is not within the range of the number of upper-limit pulses and that of lower-limit pulses, it is judged that a power consumption amount has not been measured normally even during the operation of the device 4, and an alarm signal is outputted to an alarm means 6. Then, the integrated value is cleared, whether a fault exists or not is judged by a new integrated value, and the above operation is repeated.
HASHIMOTO YASUMASA
MORITA KAZUNARI
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