Product Manual

Operation
900-0169-01-00 Rev B 19

Mini Grid
mode is also incompatible with the
Grid Use Time
and
Load Grid Transfer
functions of the MATE3
system display. These functions do not have similar priorities to
Mini Grid
or
HBX
, but they do control the
inverter’s connection and disconnection with the grid.
Mini Grid
should not be used with these functions.

When deciding whether to use
Mini Grid
mode or
HBX
, the user should consider the aspects of each.
 Mini Grid logic is based in the FXR inverter and can function in the absence of the MATE3. HBX logic is
based in the MATE3 and cannot function unless the MATE3 is installed and operating.
 Mini Grid can use utility grid power to fully recharge the batteries every time it reconnects to the grid.
HBX can only do so under specific circumstances.
 HBX set points have a wide range of settings. Mini Grid uses settings intended to protect the batteries
from excessive discharge; however, most of its settings are automatic and do not allow customization.
 HBX works more efficiently with a larger renewable source, but there is no specification for renewable
size. Mini Grid cannot work properly unless the source is larger than the size of the loads. If this
condition is not met, Mini Grid will not disconnect the inverter from the utility grid.
 Mini Grid is one of seven inverter-level functions (modes) which share a single input. Selecting it
prevents any other input mode from being used. HBX is a system-level function which can be
combined with the settings of other input modes.
 See Table 6 on page 49 for a comparison summary. Pages 48 and 49 have more information on HBX,
Grid Use Time, Load Grid Transfer, and other functions of the system display.
GridZero
In
GridZero
mode, the FXR inverter remains grid-connected, but prioritizes the use of battery or
renewable sources to run loads. It uses only renewable energy to recharge the batteries. The inverter
tries to “zero” the use of the utility grid, drawing on AC power only when needed to supplement
stored DC sources. Note that the inverter draws up to 1 Aac regardless of the DC sources.
In the MATE3 system display, the selectable options are
DoD Volts
and
DoD Amps
. The inverter sends
battery power to the loads when the batteries exceed the
DoD Volts
setting. (12-, 24-, and 48-volt
systems must exceed the setting by 0.2, 0.4, and 0.8 Vdc respectively.) As the battery voltage decreases
to
DoD Volts
, the inverter reduces the current toward zero. It will maintain the batteries at this setting.
The FXR inverter can manage large quantities of power. To prevent damage to the batteries from
rapid discharge, the rate of discharge can be limited using the
DoD Amps
setting. This item should be
set lower than the current provided by the renewable source.

When
DoD Volts
is set low, this mode allows more renewable energy to be delivered from the batteries to
the loads. However, it will also leave less of a battery reserve in the event of a grid failure.

When
DoD Volts
is set high, the batteries will not be discharged as deeply and will retain more of a backup
reserve. However, not as much renewable energy will be sent to the loads.
The renewable energy source needs to exceed the size of all loads and possible losses. The renewable
source must also charge the batteries. The inverter does not charge the batteries in
GridZero
mode.
BENEFITS
:

This mode seamlessly blends the use of battery power and grid power. It puts renewable energy to the
most effective use without selling power to the utility grid.

GridZero
mode minimizes dependence on the grid as long as certain conditions are met.

The inverter remains connected to the utility grid in case the grid is needed. If large loads require the use of
grid power, no transfer is necessary to support the loads.