state enterprise
ЛТ-1 Electronic
Electricity Meters

The ЛТ-1 electronic one-phase alternating-current electricity meter is designed to measure active energy in the one-phase two-wire alternating-current circuits, with a possibility to measure energy as per 4 tariffs, if there is a differential price for electricity.

The ЛТ-1 meters, using 2 current measuring elements, monitor and register the time of electricity thefts at a difference of currents of 0.25 А, maximum. When the meter detects a theft, the data on the theft time are registered, stored in the internal memory and output to the meter display. The meter can also transmit these data via the RS-485 or ZigBee interface. The meters increment the readings in any direction of the energy flux.

The liquid-crystal display shows the data:

  • total volume of the accounted electricity as per each of the tariffs;
  • registered summary time of electricity thieving, in minutes;
  • information on damage of the data in the internal memory;
  • current time and date.

Operating service conditions:

  • operating range of temperatures from minus 40 °С to plus 70 °С;
  • relative humidity of ambient air of 90 % at a temperature of plus 30 °С;
  • nominal voltage Unom – 230 V;
  • operating range of voltages from 176 to 253 V;
  • mains frequency – (50 ± 2.5) Hz.

Basic Characteristics:

Parameter nameParameter value
Accuracy class1.0
Nominal current strength, Іnom
Maximal current strength, Imax50, 60 А
Sensitivity12,5 mА
Meter constant1600, 3200 pulse/kW∙h, by order
Total power consumed by voltage circuit at Іnom10 V∙А, maximum
Total power consumed by current circuit at Іnom0.5 V∙А, maximum
Mass1.2 kg, maximum
Test periodicity6 years
Average service life16 years, minimum

The ЛТ-1 meters, depending on the modification, have:

  • two measuring elements in the current circuit;
  • indication of incorrect connection to the mains;
  • indication of the current difference in the phase and neutral wires;
  • LED indicator of energy consumption;
  • internal clock and calendar energized from the battery;
  • RS-485 interface output for operation of the meter in AECMAS;
  • pulse output whose closure frequency is proportional to the increment in readings of the consumed electricity;
  • internal memory which provides saving of the values of the consumed energy as per each of the acting tariffs;
  • liquid-crystal display or electromechanical counting mechanism which displays readings of the calculated energy (in case of tariff accounting, the consumed energy is displayed for each of the tariffs, by turn, at the liquid-crystal display);
  • possibility to install, in the meter body, the ZigBee wireless transmission module of 2.4 GHz for operation in the AECMAS system (ЛТ-1С).