© 2021 by XOLTA
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3.3.2.2 Typical installation with solar panels
The block schematics in Fig. 3.4 depict a typical installation of the XOLTA outdoor BESS unit
rack with solar panels.
Figure 3.4:
Typical XOLTA outdoor
BESS installation
with solar panels
3.3.2.3 Grid feeding monitoring relay (optional)
In certain grids, there is a need to install a grid feeding monitoring relay between the battery
system and the public grid. The relay collects all relevant data regarding unusual status of
the public grid and automatically disconnects or reconnects the battery inverter. The grid
feeding monitoring relay must be set up according to specific local grid requirements.
If the specific grid parameter measured by the grid feeding monitoring relay is non-compliant,
a 24V signal is no longer provided to the inverter.
The grid feeding monitoring relay connects to the three phases (L1->L3) for voltage measure-
ment and utilizes three current transformers for measuring the current flow in the grid. Current
transformers should be mounted on the three grid phases entering from the main grid meter.
IMPORTANT!
The grid feeding monitoring relay must be installed to take measurements before any con-
sumption, i.e. right after the main utility meter.
A diagram of the grid feeding monitoring relay installation is shown in Fig. 3.5.
Depending on the manufacturer, the grid feeding monitoring relays may have different outputs
for driving the enable/disable signal for the inverter. Some of them may require an intermediate
small signal relay to handle the drive signal requirement.
The diagram of this only shows the principal connection diagram.
NOTE!
If grid feeding monitoring relay is not needed in the specific location, then 24 V DC from power
supply should be permanently connected to the inverter terminal 13 (Fig. 3.6).
Figure 3.5:
Diagram of grid
feeding monitoring
relay installation
PV Installation
XOLTA BESS
Unit Rack
3 x PE, 45A
1 x N+PE, 10A
Main
Utility
Meter
XOLTA
PV Meter
XOLTA
Grid
Meter
Eth. Cable
Internet
Connection
PV Inverter
Power
Grid
CTs
CTs
Eth. Cable
Eth. Cable
Eth. Cable
Meter Supply
Fuse And
Switch
Cabinet
Eth.
Switch
Grid Phase L3
Grid Phase L2
Grid Phase L1
Grid Null
W
V
U
NULL
24V DC to inverter
PE
Main
Utility
Meter
Voltage Input
Grid Feeding Monitoring
Relay (Optional)
