Outback FXR/VFXR Renewable Series Installation Manual

Installation
900-0166-01-00 Rev B 33
Parallel Stacking (Dual-Stack and Larger)
In parallel stacking, two or more inverters create a single, common 120 Vac
5
bus.

The slave outputs are controlled directly by the master and cannot operate independently.

All inverters share a common input (AC source) and run loads on a common output.

Slave inverters can go into Silent mode when not in use. The master will activate individual slaves based on
load demand. This reduces idle power consumption and improves system efficiency.

Up to ten inverters may be installed in a parallel arrangement. The example on this page shows three
inverters. The wiring diagram on the next page shows four. All inverters must be the same model.
Figure 25 Example of Parallel Stacking Arrangement (Three Inverters)
When installing a parallel inverter system, observe the following rules.

Parallel stacking requires both the system display and the communications manager. See the HUB10.3
literature for any required jumper configurations.

The inverter that is mounted physically lowest is always the master and is programmed as
Master.
Mounting below the other inverters allows the master to avoid heat buildup and remain relatively cool as it
sees the greatest duty cycle.

The master must be connected to port 1 of the communications manager. Other inverters must not be
selected as master.

All slave inverters, regardless of number, should be selected as
Slave
during programming. Slaves can be
connected to any port numbered 2 and above.

All overcurrent devices must be sized for 60 Aac or less. All wiring must be sized for 60 Aac or more.

All output circuit breakers must be sized appropriately for loads and inverter power.

The AC input (generator or utility grid) must be a single-phase source of the proper voltage and frequency.

When wiring the AC source to the inverters, local codes may require the inverter circuits to be located at the
opposite end of the panel from the main circuit breaker. This prevents overloading of the AC bus.
5
Output voltages may vary with regional voltage standards.
6.0 kVA
120 Vac
2.0 kVA 120 Vac
2.0 kVA 120 Vac
2.0 kVA 120 Vac
LOAD
PANEL
Master Slave Slave