Product Manual

Operation
900-0161-01-01 Rev B 17
If the inverter is connected to the utility grid and the charger is turned off, another source such
as renewable energy should be present to charge the batteries. The inverter will observe the
batteries as if it was charging. When the batteries reach the required voltage and time to end
the cycle, the inverter will disconnect from the grid. This means that the renewable source
regulator settings must be the same as the inverter (or higher). Check both settings as needed.
See page 26 for more information on the battery charging cycle.
BENEFITS
:

Mini Grid
mode allows a system to minimize or eliminate dependence on the utility grid. This is only
possible if certain conditions are met. See below.
NOTES
:

The Radian inverter will offset the loads with excess renewable energy if it is available from the
batteries. See page 36 for more information on
Offset
operation. However,
Offset
is inapplicable
when the Radian disconnects from an AC source. The renewable energy supports the inverting
function instead.

This mode has similar priorities to the high-battery transfer (
HBX
) function used by a MATE3-class
system display. However, it is not compatible with
HBX
and cannot be used at the same time. When
using
Mini Grid
mode, the user should disable
HBX
to prevent conflicts.
Mini Grid
mode is also incompatible with the system display
Grid Use Time
and
Load Grid Transfer
functions. These functions do not have similar priorities to
Mini Grid
or
HBX
, but they do control the
inverter’s grid connection and disconnection.
Mini Grid
should not be used with these functions.

When deciding whether to use
Mini Grid
mode or
HBX
, the user should consider aspects of each.
 Mini Grid logic is based in the Radian inverter and can function in the absence of the system
display. HBX logic is based in the system display. It cannot function unless the system display 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 which protect the batteries
from excessive discharge; however, most 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 renewable source is larger than the
loads. If this condition is not met, Mini Grid will not disconnect the inverter from the 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 the system display literature for more information on HBX mode, Grid Use Time, and
Load Grid Transfer.