External Auxiliary Supply Status Monitoring; Sel-751 Control - ABB OVR-15 Instruction, Operation And Maintenance Manual

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06 SEL-751 display screen
and front-facing LEDs
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07 SEL-751 modules
• In the case of frequent and long duration
external power outages, the battery
frequently undergoes discharge and charge
cycles. This reduces battery capacity,
charging efficiency and overall service life.
• During consistent long duration outages,
the battery bank voltage may drop below 18 V
(9 V per battery), indicating battery may have
deep discharged and cannot be charged
again. At this point, the battery must be
completely replaced with a brand new, fully
charged, equivalent battery.
• Connection of any additional load to the
battery is strictly prohibited, and ABB will
not be liable for any adverse impact this can
cause to recloser performance, including
battery life.
Handling reclosers during long outages
1. If the battery bank is healthy and in fully
charged condition (i.e., ≥24 V DC), no
special attention is required if the power
outage is less than 24 hours in duration.
2. If a power outage lasts more than 24 hours
OR typically >10 CO operations after power
failure, then it is considered a long duration
power outage requiring special attention
to the batteries.
3. During long outages, the batteries may
become drained to such a level that they go
into deep discharge stage (i.e., battery bank
voltage goes below 18 V).
4. In this situation, the recloser will not be able
to recharge the batteries automatically and
external charging may be required. Such
a situation may also damage the batteries
permanently, thus requiring battery
replacement.
5. To avoid this, if a power outage is expected
to last more than 24 hours, disconnect the
batteries from the circuit at the beginning
of the outage. When the outage ends and
power resumes, reconnect the batteries
to the circuit.
6. If a power outage lasts more than a month,
charge the batteries externally at regular
intervals to ensure the battery bank voltage
is always higher than 21 V DC.

4.2.6 External auxiliary supply status monitoring

In the event of loss of external auxiliary supply,
the programmable battery charger sends a signal
to the SEL-751 relay over an independent binary
input. Thus, the status of availability of external
auxiliary power to the LV unit can be monitored
remotely if communication setup is available.

4.2.7 SEL-751 control

The OVR-15, 27 and 38 recloser LV cabinet is
supplied with the microprocessor-based SEL-751
intelligent electronic device (IED).
In the SEL-751, all card slots connections are made
with terminal blocks that are affixed to the frame
of the IED. This is powered by the charging device.
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06
Definite time setting of 0 ms shall not be used
with OVR-15/27/38.
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07