FIELD: electricity.
SUBSTANCE: circuit comprises a three-phase electronic electric counter properly connected via a lead to two phases and a zero conductor of a power transmission line, and its phase outlets are connected to a load via a unit of packaged automatic safety fuses - circuit breakers, and a metering outlet of the three-phase electronic electric counter is connected to a metre of time intervals. It includes a unit of load currents compensation, comprising the following components connected to the oulet of the operating phase: a controlled autotransformer (CAT), connected with a step-down transformer, and a controlled load, for instance, in the form of a rheostat, in the circuit of which there is an amperemetre installed. And voltage on the controlled load is measured with a voltmetre. The secondary winding of the step-down transformer is connected to a current circuit of a free phase pair of clamps of the three-phase electronic electric counter so that current in this current circuit is oppositely directed relative to current direction in other phase current circuits. The phase conductor supplying to a unit of load currents compensation, is additionally connected with the secondary winding of the step-down transformer, and in the point of connection of the secondary winding of the step-down transformer with a phase conductor of the unit of load currents compensation, there is a three-pole amperemetre installed for difference of controlled load current and compensation current.
EFFECT: simplified procedure for assessment of sensitivity of an electronic three-phase electric counter to low variations of load current in a wide range of current consumed by a load, considerable reduction of measurement time.
1 dwg
