AC Coupling Guide

Installing
Each PV inverter requires its own AC breaker in the panel to which it is connected.
Although there is room to add breakers for the PV inverters directly into the XW Pro
Power Distribution Panel, it is easier to install the breakers in the AC sub panel. These
breakers must be installed according to the XW Pro Installation Guide (document number
990-91228 or 990-91403). The sub-panel may also contain load breakers.
To install an AC-coupled system:
1. Install one or more XW Pro inverters according to its Installation Guide.
2. Install one or more PV inverters according to their Installation Guides, and connected
to the panel that is backed up by the XW Pro battery inverters.
Recommended Settings
NOTICE
RISK OF DAMAGE TO THE BATTERY OR BATTERY INVERTER
Always follow the recommended settings described below. The battery and the XW Pro may
be subject to DC over-voltage and/or over-current events in backup power or off-grid
operation. The below settings aim to achieve maximum system stability.
Failure to follow these instructions can result in equipment damage.
The XW Pro AC coupling controls may temporarily disconnect the PV inverters, as
needed, based on battery state of charge, voltage, and the amount of power coming from
the PV system.
Setting Value Notes
AC
Coupling
Enabled
Enables frequency-shifting mechanism in the
battery inverter.
AC PV
Charge
SOC
90%
Recommended. Threshold for SOC-based
frequency shifting. Increased PV curtailment at
high SOC helps regulate the battery voltage and
charge within the target range.
SOC
Control
Enabled
Recommended. This requires external BMS or
Conext Battery Monitor.
Grid Code
The battery inverter grid
code must be set according
to local utility interconnect
requirements.
Ensure that grid code settings match the PV
inverter.
For advanced off-grid configuration refer to "Off-
Grid Operation" on the next page.
For advanced grid code configuration or
troubleshooting see "Troubleshooting" on
page1.
Table 1Battery inverter settings
Planning and Installation XW Pro AC Coupling Solutions Guide
990-6421 This manual is intended for use by qualified personnel 15