Mains Failure Operation; Mains Recovery Operation - GE 8 Series Operating Manual

4.2.3 Mains failure operation

When the Mains is no longer within acceptable tolerances,
the Battery will provide the DC power to the Inverter.
The Inverter will maintain continuous AC power to the
Load until the Battery Voltage reaches the lower limit of
the Inverter operation capability.
During the discharge, the LCD screen displays the
estimated time the Battery can support the critical load.
Prior to complete Battery discharge, the "stop operation"
alarm (shutdown imminent) warns the operator that the
Battery is almost discharged and the UPS is about to shut
down.
In case of parallel operation
With a Parallel System for power capacity (see Section 4.3)
• With the Bypass Mains power available, a "Battery low" warning on any unit will cause the Load
to be transferred to Mains (after a selectable time delay).
• With Bypass Mains power not available, a "Battery low" warning on any unit will start the "stop
operation" timer (adjustable).
The Load will shut down at the end of the "stop operation" time period.
With a Parallel System for redundancy (see Section 4.3)
• When a Battery low warning occurs on a unit not necessary to support the present load, this unit
will shut down after a timeout period (selectable).
The Load is shared between the other units.
• As the warning occurs on one unit necessary to support the present load, the system starts the
"stop operation" timeout (selectable).
The Load will shut down at the end of the "stop operation" time period.

4.2.4 Mains recovery operation

As soon as the AC input power recovers, the Rectifier will
start automatically, supplying DC power to the Inverter
and recharging the Battery.
If the Inverter was previously shut down due to low
Battery, the Load will be initially powered by Mains
through the Automatic Bypass.
When the Battery is sufficiently recharged to ensure a
minimum time of operation with the present load, the
Inverter will start automatically and the Load will be
transferred back to the Inverter.
In case of parallel operation
When the AC input power recovers, the Rectifiers will start up sequentially, according to their
number in the Parallel System. This minimizes the initial inrush current.
The Inverters will start up automatically, but only when the Battery has been sufficiently recharged
for a minimum runtime with the present load.
When enough Inverters to supply the Load have been restarted, the Load will be transferred from the
Automatic Bypass back to the Inverter output.
Modifications reserved
OPM_SPE_XXX_10K_40K_8GB_V020.doc
Fig. 4.2.3-1 Block diagram Mains Failure operation
Fig. 4.2.4-1 Block diagram Mains recovery operation
Operating Manual SitePro 10-15-20-30-40 kVA / S8
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