Landis & Gyr Cashpower Gemini PLC User manual - page 23
Meter Operation - Prepayment Mode Released
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Cashpower Gemini PLC
– User Guide
© Landis+Gyr (Pty) Ltd
If the preset power limit threshold is exceeded, the load switch will open for a period of 30s,
after which it will re-close (either automatically or manually
– 7.10). If the power limit threshold
continues to be exceeded, the above process is repeated. If, after 4 power-limit events within a
15-minute window, the limit is still being exceeded because of excessive energy consumption,
the load switch will be opened for a period of 30 minutes (the power limit lockout period). At the
end of the lockout period, the load switch will re-close (either automatically or via a manual
operation on the keypad
– 7.10) and, unless the excessive loading has been removed, the
process will be repeated. Note that vouchers may be entered and the information modes
accessed as normal during the power limit lockout period.
If the power drawn by the customer is reduced in response to a power limit disconnect, the
event will be ignored after 15 minutes has elapsed.
NB: Power limiting is not a form of safety overload protection. It is designed to generally limit the
overall usage of power in a particular area (possibly dictated by reticulation limitations or linked to a
tariff allocation).
7.9
Reverse Power Detection and Metering
The metering circuitry can detect and measure reverse power. A filter ensures that short periods of
reverse power are ignored e.g. as a result of a motor running down and only significant reverse power
detected. A significant reverse power condition will be flagged when there has been a continuous
reverse power measurement equivalent to 50Wh.
Under reverse power conditions, metering will continue as normal i.e. credit will continue to be
decremented.
7.10 Automatic/Manual Load Reconnection
In some instances, local safety regulations require that the meter not automatically re-close the load
switch after, for example, a power limit trip. Under these conditions, the load switch will remain in the
open state until such time as a key is pressed on the keypad.
Using the example of a power limit trip
– refer to 7.8, the load switch will open and remain open for a
period of 30 seconds. At the end of this 30-second period, the display will return to normal but,
instead of the load switch closing, the load switch status icon on the LCD will start to flash, toggling
between an open and closed state. This is a visual indication that the load switch may now be
manually closed, by pressing any key on the keypad.
In the event of the load switch opening due to expiry of credit, it will only be able to close again on
entry of a valid credit voucher. The manual action of entering a credit voucher via the keypad, results
in the load switch closing when the last digit of the voucher is entered and accepted by the meter.
Automatic/manual load reconnection is a configurable option, set at the time of manufacture
– 11.15.
It may also be changed at any stage with a suitable engineering voucher.
7.11 Disconnect on Power Failure
This option, configurable at the time of manufacture
– 11.15) forces the meter‟s load switch to open
whenever there is a power failure. The option can be invoked as a means of preventing the meter
from being installed fraudulently with line and load connections reversed, in which case the meter will
never power up once the load switch is open.
Display during 30-second
power limit periods
Display during 30-minute
power limit lockout period