Islanding Mode; Sleep Mode; Power Search - Generac Power Systems PWRcell 9 Owner's Manual

General Information

Islanding Mode

In the event of a grid outage, the PWRcell inverter enters
Islanding Mode. During Islanding Mode, the inverter
disconnects from the utility grid and powers the building
from the REbus nanogrid.
In a typical solar-plus-storage configuration, this means
the battery and all REbus-connected batteries will work
together with the PV links to supply power to REbus. The
inverter will pull power off of REbus to provide AC power
to the building.
NOTE: To island during a power grid outage, the inverter
islanding setpoint must be set to YES and the system
mode can not be set to Grid Tie. See the Generac
PWRcell Inverter Owner's Manual for more information.

Sleep Mode

While in Islanding Mode, the battery charges from REbus
when PV power is greater than local demand. However,
as the battery provides power to building loads, its state
of charge (SoC) decreases. Once the battery SoC
reaches the Min Absolute setpoint, the system enters
Sleep Mode. In Sleep Mode, the inverter shuts down, and
the building loses power. See
(SoC) Setpoints for more information.
10
Battery State of Charge

Power Search

DANGER
Electrocution. Turn battery disconnect OFF and
de-energize REbus before touching terminals.
Failure to do so will result in death, serious injury,
equipment and property damage.
While in Sleep Mode, the battery performs Power
Searches at regular intervals.
During a Power Search, the battery wakes up, energizes
the REbus nanogrid, and scans for potential sources of
power. If a PV Link or another source of power is
available, then the battery will begin charging. Once the
battery SoC is 5% above the Min Absolute SoC setpoint,
the PWRcell system may resume exporting power to
support backup loads when islanded. If Power Search
does not discover other sources of power, the battery
returns to sleep to conserve energy.
The length of time Power Search keeps REbus
energized before returning to sleep and the Power
Search interval are user-adjustable and are set on the
inverter control panel. See the Generac PWRcell Inverter
Owner's Manual for more information.
Table 2-3. Default Power Search Values
Setpoint Description
Sleep Time Minutes between Power
Searches
PowSrch Time Minutes
keeps REbus energized
The battery can only perform a Power Search a certain
number of times before it runs out of energy completely.
The number of searches available is dependent on the
value of the Min Absolute Soc setpoint. Once the battery
depletes its Power Search reserve, the battery will not
energize the REbus nanogrid on its own. Another source
of power is required to energize REbus and charge the
battery.
See Battery State of Charge (SoC) Setpoints
information.
NOTE: Turn Battery Disconnect OFF whenever the
PWRcell inverter will be disabled for a long period of
time. This prevents Power Search from running the
battery down below its minimum SoC.
Owner's Manual for Generac PWRcell Battery
(000599)
Default
60
Power Search 4
for more