Measuring Principle; Overview; Signal Generation - Landis+Gyr E350 Series User Manual

Description of Unit
2.6

Measuring Principle

2.6.1

Overview

Inputs
Outputs
Power supply
Memory
2.6.2

Signal Generation

D000027979 en t – E350 Series 2, 3-Phase ZxF100Ax/Cx – User Manual
The main meter inputs are:

Phase connection (L1, L2, L3) and neutral for
- energy measurement
- three-phase power supply of the meter
- PLC communication with communication modules (all phases
prepared)

Display button

Supply control switch button (only if meter equipped with supply control
switch)
The main meter outputs (partly also inputs) are:

LCD to display measured values and the corresponding OBIS code

Pulse output LEDs (red, one for active and one for reactive energy)

Optical interface for automatic data readout on site by means of a
suitable PDA (also input)

Secured AMR Interface for automatic data readout through a
communication module, e.g. E35C module, with a PLC, GSM/GPRS,
Ethernet or other medium (also input).
The supply voltage for the meter electronics is taken from the three-phase
system. A voltage monitor guarantees a safety data storage in the event of
a mains voltage failure and a correct start-up after the return of the voltage.
A non-volatile memory (EEPROM) contains the parameter set of the meter
and secures the stored measurements against loss due to power failure.
The three measuring elements, DFS (Direct Field Sensor), register the
phase currents with the magnetic field of the current loops and the phase
voltages over a resistor divider. The analog/digital converters transform
both signals into digital voltage and current data. This data is then
multiplied by a digital multiplier to produce an energy proportional value.
The resulting value is fed into the microprocessor, which adds the value to
the corresponding values of the other phases and the sum is then
transferred into the corresponding energy registers (rate-dependent) .
The microprocessor generates pulses for the pulse output LEDs from the
digital sum to the meter constant R.
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