Landis+Gyr E650 Series User Manual page 10

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Inputs
Outputs
Measuring system
Signal processing
© Landis+Gyr AG
The main meter inputs are:

Connections of phase voltages (U1, U2, U3), phase currents (I1, I2, I3)
and neutral conductor N
– for processing in the measuring system
– for the three-phase power supply to the meter and voltage monitor

Control inputs U
t
– Changeover of energy and demand tariff rates
– Resetting
– Demand inhibition
– Synchronizing
Opto-couplers protect the internal circuitry from interference, which
could otherwise enter via the control inputs.

Keys
– for display control (display keys, optical interface)
– for resetting or service functions (reset key)

Pulse inputs for connection of external pulse transmitters (only for
meters equipped with a communication unit)
The meter has the following outputs:

LCD display with display keys for local reading of billing data (single 8-
digit display with additional information, such as energy direction, type
of energy, presence of phase voltages and identification number)

Optical test outputs (red, 1 in active energy meters, 2 in combimeters)

Alert LED (red) to indicate alerts on the front face of the meter

Static relay with freely parameterised signal assignment (2 fixed, plus
up to 6 others on the extension board)

Optical interface for automatic local data acquisition by a suitable
acquisition unit (handheld terminal)

Communication interfaces of various kinds in the communication unit
(see also section 1.7 "Communication")
The input circuits (voltage dividers and current transformers) record voltage
and current in the individual phases. Analogue-digital converters digitise
these values and feed them as instantaneous digital values via calibration
stages to a signal processor.
The signal processor determines the following measured quantities from
the instantaneous digital values of voltage and current for each phase and
forms their mean value over one second:

Active power per phase

Reactive power per phase (combimeters ZxD400CT only)

Phase voltages

Phase currents

Network (mains) frequency

Phase angles
D000030110 d – E650 Series 3 (ZMD400AT/CT, ZFD400AT/CT) – User Manual
(3 fixed, plus up to 4 others on extension board) for:
Description of Unit