Annex I: Typical Functional Characteristics Of Sealed Lead Acid Batteries - ABB OVR-15 Instruction, Operation And Maintenance Manual

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12 Annex I: Typical functional
characteristics of sealed lead acid batteries
This annex covers the typical functional
characteristics of the batteries used in OVR
three-phase reclosers. Each LV control cabinet
for the OVR reclosers contains two 12 V batteries
connected in series. Please confirm the Ah rating
for your recloser from the order-related
drawings.
Storage and self-discharge characteristics
If commissioning of the recloser is delayed, the
batteries should not be left unattended because
their self-discharge characteristic limits the
storage period. Storage temperature has
significant impact on the storage period as
shown in following graph. In cases of extended
storage of the recloser control cabinet, the
batteries should be charged every three months.
Open circuit voltage characteristics
When the batteries provided with OVR recloser
are in healthy condition, the remaining capacity
on the battery at different open circuit voltage
across each battery terminal is indicated in the
following graph.
The OVR recloser will continue to function on
battery backup as long as the combined battery
voltage is above 21.5 V (10.75 V per battery).
If the battery bank voltage falls below 21.5 V, the
OVR recloser will provide a BATTERY NOT OK
indication and will initiate a load management
algorithm with disconnection of loads such as
relay and communication modem to prevent the
battery from going into deep discharge mode.