Device description
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D000062026 en a
– E650 Series 4 – ZMD400AT/CT, ZFD400AT/CT – User Manual
© Gyr
range without the supply voltage having to be adjusted. A voltage monitor
ensures correct operation and reliable data recovery in the event of a
power failure and correct restarting when the voltage is restored.
For medium or high-voltage applications in particular, the measuring
voltage can be switched off. Since the meter normally obtains its supply
from the measuring voltage, it is also switched off and cannot be read. The
auxiliary power supply connected in parallel with the normal power supply
ensures operation of the meter free from interruption, so that it can be read
at any time. The auxiliary power supply is situated on an extension board.
The extension board is fitted inside the meter and is secured by the
certification seals. It cannot be exchanged. It can have the following
components:
up to 4 control inputs in combination with
up to 6 output contacts (solid-state relays)
up to 2 relays outputs
an auxiliary power supply
The communication unit for fitting only in the ZxD400xT meters is a
complete unit in its own case. If present, it is situated behind the front door,
and is therefore secured by a utility seal and can be exchanged or inserted
in the field, if necessary. It contains:
Communication interfaces as required for remote readout of the meter
(e.g. CS, RS232, RS485, modem)
2 signal inputs (S0 interfaces) for processing external pulse transmitters
2.6
Measuring system
Figure 2. Block schematic diagram of measuring system
2.6.1
Input signals
The meter has the analogue current values I1, I2 and I3 and analogue
voltage values U1, U2 and U3 available as input signals.
Figure 3. Type of measurement ZMD400xT
Since the ZMD400xT measures the individual phases mutually
independently with one measuring element each, it can record the sum of
the three phases, the individual phases themselves, the phase angle
between voltage and current as well as the angle between voltages U1
–U2
and U1
–U3.
Auxiliary power
supply
Extension board
Communication unit
ZMD400xT
