130/143
Issue 1.2
Power-up/power-down procedure
© Gyr
D000058620 en a
– E470 Series 3 SMETS2 100 mm – ZCX310 – User Manual and Functional Description
23
Power-up/power-down procedure
This section describes the detection and the handling of total power
failures. A total power failure is detected directly from the power supply of
the device and works independently of the voltage measurement.
23.1 Power-down (PD)
After a power failure, the internal power supply voltage starts decreasing.
As soon as the ‘power-down’ threshold is reached, all functions of the
device are disabled and the power-down procedure is initiated.
Figure 36
Power-down procedure
The meter can communicate via any communication channel only until the
power fail threshold is reached.
23.1.1 Bridging time
The device allows a time of up to 0.5 s within which the power failure will
have no effect except restrictions in communication (bridging time per IEC).
Thus, the device will retain its full functionality (also restore
communications) if power is restored within this time.
23.1.2 Power-down procedure
If the power-down threshold is reached, the power-down procedure is
initiated and the device stops handling the inputs, outputs and all non-
disabled communication interfaces. Now the device saves all relevant data,
such as:
Time and date
All energy registers
All status registers
Power-down time
Once the power-down procedure has started it cannot be interrupted.
Therefore, the device will complete the procedure even if the voltage is
restored shortly after the data storage was initiated. In this case, however,
the device will restart immediately after the power-down procedure is
completed.
