Outback Power Systems GS8048 - Manual (Page 37)

Installation
900-0021-01-00 Rev A 35
Multiple-Inverter AC Installations (Stacking)
Installing multiple inverters in a single AC system supports larger loads than a single inverter can
handle. This requires stacking. Stacking inverters does not refer to physically placing one on top of
another. It refers to how they are wired within the system and then programmed to coordinate
activity. Stacking allows all units to work together as a single system. The Radian Series GS8048
inverter/charger can only be stacked in parallel. Up to ten units can be stacked.
Figure 25 OutBack HUB4 and MATE3
Each inverter must be assigned a status — “master” or “slave”. The master is the primary and most
heavily used unit. The master inverter’s Remote port must connect to port 1 on the HUB.
Slave inverters provide assistance when the loads are more than the master can handle alone. Slaves
plug into ports 2 and above on the HUB. See the MATE3 manual for other port restrictions pertaining
to stacking. In general, it is always important to keep track of units and ports for programming
purposes.
Programming involves using the MATE3 to assign a status and stacking value to the inverter on each
port. These assignments can be changed at any time as long as the master is plugged into port 1.
IMPORTANT:
 The master inverter must always be connected to port 1 on the HUB. Connecting it
elsewhere, or connecting a slave to port 1, will result in backfeed or output voltage
errors which will shut the system down immediately.
 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. Overloading may cause circuit breakers to open or
the inverters to shut down.
Port 1 Additional Ports MATE3 Port
MATE3 HUB4
Stacking Connections
Stacking requires an OutBack HUB product, as well as the OutBack MATE3 system display. A system
using four or fewer components may use the HUB4. Systems using up to ten components require the
HUB10. All interconnections are made using CAT5 non-crossover cable.