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Fusesaver health
The Fusesaver health LEDs indicate the
operational health for each phase on the
line. A Fusesaver's health can be "OK",
"PROBLEM" or "No Data" if no data is
available for that phase.
A FS is deemed to be "Health OK" if all of the
following conditions are met:
The phase is correctly configured.
Communications to the FS is healthy.
The FS communications module battery
life is not low.
The FS VI is not worn out.
The FS does not have a mechanism
fault.
A Fusesaver is deemed to have a "PROBLEM"
if any of the following conditions are met:
There is a communications problem to
the FS.
There is a problem with the FS
configuration (RCU problem LED will
also be red).
The FS communications module battery
life is low.
The FS VI is worn out.
The FS has a mechanism fault.
Both LEDs will be off under the following
circumstances:
There is no FS for that phase.
The RCU is currently in the process of
checking the FS configuration (RCU OK
LED will be flashing)
The state of the FS communications
module, FS VI or FS mechanism is
unknown as data for these points has
not been updated recently.
Time management
The RCU has in internal real time clock,
which runs on Coordinated Universal Time
(UTC).
Time is set either by the RCU Connect utility
to match the PC or by the SCADA protocol (if
supported by the protocol and the master
station). Time is maintained in the RCU
during loss of supply by using the standby
battery. If the battery is disconnected or
turned off for more than one hour, time
may be lost and must be reset when power
is restored to the RCU, usually the SCADA
protocol will do this.
On power up, the RCU acquires time from
the following sources in this order:
The battery backed up clock
The SCADA system
The Fusesaver time master if SCADA
time not acquired.
The RCU sets time for the line Fusesavers
every 24 hours and when time is set by the
SCADA system.
Fusesaver availability monitoring
The Fusesaver protection is only armed
when the line current is sufficient to power
the Fusesaver (line power is needed for
protection even if a communications
module is fitted). At times of low demand, it
is possible that the line current will fall low
enough such that the Fusesaver protection
is inactive. It can be difficult to ascertain if a
particular line has enough current for some
or all of the day for the Fusesaver protection
to be armed. Fusesavers installed on sites
with inadequate line current will not provide
the improved network reliability and return
on investment potentially forecast by the
user.
To assist the user in assessing that
Fusesavers have been installed on lines with
adequate line current, the RCU monitors the
line current ON flag in the Fusesaver and
determines the Fusesaver protection
availability over the previous 24 hours for
which Fusesaver data is available. The RCU
then provides this as an analog database
point for the SCADA system (APID 23, 24,
25). This enables SCADA monitoring of the
Fusesaver protection availability.
These points are updated every 2.4 hours
and are initialized to 100.00% on restart.
Note that no line current due to the
Fusesaver being open is included as an
outage in the availability calculation.
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