摘要 |
FIELD: electrical measuring equipment, applied for check-up of connection of electric meters to three-phase four-wire mains. ^ SUBSTANCE: the instrument has a casing, light-emitting diode indicator, prods for connection to the terminals of phase A of the meter and to the terminals of phases B and C, current transmitter, electronic circuit and a terminal for connection to the neutral terminal of the meter. The electronic circuit has a channel of the measured signal with a prod for connection to phases B and C, as well as the current transmitter, reference signal channel with a prod for connection to phase A and current transmitter, indication channel and a power unit. The channel of the measured signal and the reference signal channel are connected in parallel with the indication channel. ^ EFFECT: provided check-up without de-energizing and breaking of current circuits within a wide range of currents flowing through the meter. ^ 7 cl, 4 dwg
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