Xantrex Technology SW Plus 4024 - Manual (Page 195)

Menu Item Descriptions
976-0043-01-02 7–17
21A Grid Usage
This menu item allows you to select between the set points SB and BX as
described below.
SB (Standby) - Utility Backup This set point is the first set point
selection in the 21A Grid Usage menu. It sets the inverter to be used as a
backup power supply. When AC power is available at the inverter’s AC1
input, the batteries are maintained until the AC power is lost. At which
point, the inverter supplies AC power to the load from the batteries.
This is the default setting for grid usage. This mode also allows for energy
management features such as Time-of-Use Metering and Peak Load
Shaving which are programmed in menu items 21B Grid Usage Begin
h:m and 21C Grid Usage End h:m.
See “Energy Management” on page 2–44 for information regarding
Energy Management Features.
BX (Battery Transfer) - Renewable Energy Backup This set point is
the second selection in 21A Grid Usage and works in conjunction with
Menu Heading 22 Battery Xfer (BX). It allows the batteries to power the
AC loads until the batteries discharge to the settings in menu 22B Low
Xfer (LBX) VDC and then transfers to the utility.
Utility grid power is then used as a backup source to keep the loads
powered. When the batteries have recharged from an external DC source
to the setting in menu 22A High Xfer (HBX) VDC, the inverter transfers
from the utility grid back to inverter supplied AC power.
Guidelines for setting this menu item:
• In the BX Modethe batteries will only be charged from the DC
source, not by the
Sine Wave Plus . The utility grid is only used to
pass-through the AC to the loads when the batteries are discharged to
a preset level.
• The BX Mode and Grid Usage Timer are not optimized to work
together. These two features can have different priorities and may
conflict with each other.
21B Grid Usage Begin h:m
This menu sets the daily begin time when the inverter is allowed to be
connected to the grid. This timer is only used when SB is selected in
21A Grid Usage. When the timer allows the inverter’s AC1 input to
connect to the grid, the inverter samples the utility grid power, and if
within acceptable tolerances, starts to charge the batteries at the bulk then
float voltage levels or goes Silent (based on the selection made in menu
item 12A Finish Stage.
21A Grid Usage
SB BX
21B Grid Usage
Begin h:m