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simultaneously providing regulated power to the load for all line and load
conditions within the range of the UPS specifications.
1. Overload Capability: The output power stage (inverter) is capable of
withstanding 150% overload for 30 seconds, 125% overload for 1 minute, or
105% overload for an indefinite length of time.
2. Output Contactor: The output power stage (inverter) is equipped with an
output mechanical relay to provide physical isolation of the inverter from the
critical bus. With this feature a failed inverter will be removed from the critical
bus.
3. Battery Protection: The inverter is provided with monitoring and control
circuits to limit the level of discharge on the battery system.
B. Battery: Upon failure of the AC input source, the critical load continues being supplied by
the output inverter, which derives its power from the battery system. There is no
interruption in power to the critical load during both transfers to battery operation and
retransfers from battery to normal operation.
1. The UPS battery system is comprised of battery modules. Replacement
batteries are user-replaceable, hot-swappable replacement battery
cartridges (RBCs).
2. For 5 kVA and 6 kVA models, a minimum of two battery cartridges must be
installed, providing 192 VDC nominal for the DC bus rail.
3. For 8 kVA and 10 kVA models, a minimum of two battery cartridge pairs
must be installed, one pair providing 192 VDC nominal for the positive DC
bus rail and the other pair providing 192 VDC nominal for the negative DC
bus rail.
4. The batteries of the UPS models in this specification are maintenance-free, leak-
proof, valve-regulated lead-acid (VRLA) batteries with suspended electrolyte.
5. The UPS incorporates the Intelligent Battery Management system to continuously
monitor the health of each removable battery module as well as external battery
modules installed in extended run battery cabinets. This system notifies the user in
the event that a failed or weak battery module is found.
6. Add additional battery packs to increase runtime. These packs and the modules
within them are hot-pluggable, allowing for easy and quick installation or
replacement without the need for electrical wiring, electrician services or powering
down of the UPS. The maximum number of external battery packs that may be
connected to the UPS is limited to 10 for all units
7. The UPS is shipped with battery modules preinstalled but disconnected.
C. Charging: Upon restoration of the AC input source, the UPS simultaneously recharges
the battery and provides regulated power to the critical load.
1. The intelligent battery management system contains a temperature
monitoring circuit and compensation algorithm that regulates the battery
charging voltage and current so as to optimize battery life.
2. The battery charging circuit remains active when in bypass or online states.
3. The UPS can be restarted immediately after a prolonged power outage
without waiting for the battery to be recharged.
D. Bypass: During bypass operation the utility power is connected to the load, bypassing
the internal converters. The system automatic bypass provides a transfer of the critical
load from the Inverter output to the automatic bypass input source during times when the
inverter cannot support the load. The UPS constantly monitors the output current, as well
as the bypass source voltage, and inhibits potentially unsuccessful transfers to automatic
bypass from taking place. The design of the automatic bypass switch power path
consists of a bypass relay for 5 kVA and 6 kVA models, and a heavy-duty
electromechanical bypass contactor for 8 kVA and 10 kVA models.
1. Automatic Transfers: An automatic transfer of load to bypass takes place if the
load on the critical bus exceeds the overload rating of the UPS, if both normal and
battery operation modes are unavailable, if the UPS has an internal fault, or if for
any reason the UPS cannot support the critical bus . Automatic transfers of the
critical load from bypass back to normal operation takes place when the overload