Landis+Gyr E650 Series 4 User Manual page 15

Device description
Outputs
Measuring system
Signal processing
D000062026 en a – E650 Series 4 – ZMD400AT/CT, ZFD400AT/CT – User Manual
– Changeover of energy and demand tariff rates
– Resetting
– Demand inhibition
– Synchronising
Optocouplers protect the internal circuitry from interference, which
could otherwise enter via the control inputs.

Buttons
– for display control (display buttons, optical interface)
– for resetting or service functions (reset button)

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 buttons 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)

Optional alarm LED (red) to indicate alarms 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)

Relay outputs with limited parameterised signal assignment due to
limited life expectancy (up to 2 on the extension board)

Optical interface for automatic local data acquisition by a suitable
acquisition unit (PDA)

Communication interfaces of various kinds in the communication unit
(also see section 2.8 "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 (ZxD400CT combimeters only)

Phase voltages

Phase currents

Network (mains) frequency

Phase angles
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