Product Manual

Operation
900-0145-01-01 Rev B 37
the following message:
An inverter firmware mismatch has been detected. Inverters X, Y, Z
2
are disabled.
Visit www.outbackpower.com for current inverter firmware.

Installing multiple inverters without stacking them (or stacking them
incorrectly) will result in similar errors and shutdown.

Although stacking allows greater capacity, the loads, wiring, and
overcurrent
devices must still be sized appropriately. Additional terminations or bus
bars may be required. Overloading may cause circuit breakers to open or
inverters to shut down.
Parallel Stacking (Dual-Stack and Larger)
In parallel stacking, two or more inverters are stacked to create a single, common AC output.

All inverters share a common input (AC source) and run loads on a common output bus. The master inverter
provides the primary output. The slaves are connected to the same output and assist the master.

The slave outputs are controlled directly by the master and cannot operate independently.

Slave inverters can go into Power Save 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.
Figure 8 Example of Parallel Stacking Arrangement (Three Inverters)
2 The port designations for the mismatched inverters are listed here.
21 kVA
230 Vac
7 kVA
230 Vac
7 kVA
230 Vac
7 kVA
230 Vac