JLSZV-35 series three-phase outdoor dry-type high-voltage combined transformer (with meter is called power metering box), respectively suitable for 50Hz or 60Hz three-phase AC, rated voltage of 35kV power grid for energy measurement, and installed in the power supply transformer On the high-voltage side of the high-voltage line, the instrument box is equipped with a three-phase active watt-hour meter and a reactive watt-hour meter, or a combined active and reactive power electronic meter, which is a metering device used to directly measure active and reactive energy in high-voltage lines.