Outback Power Systems GS4048A Operators Manual - Manual (Page 38)

Operation
36 900-0161-01-00 Rev A
Multiple-Inverter Installations (Stacking)
Multiple inverters in a single system can support larger loads than a single inverter can handle.
Installing inverters in this configuration is called “stacking”. Stacking inverters refers to how they are
wired within the system and then programmed to coordinate activity. Stacking allows all units to
work together as one system. The GS8048A and GS4048A models can stack up to ten units in parallel
for increased capacity.
Stacking requires an OutBack HUB Communications Manager, as well as a MATE3 system display.
There are usually other specialized stacking instructions during installation.
 A system of four or fewer units may use the HUB4.
 Systems of up to ten units require the HUB10 or HUB10.3.
 All interconnections between the products are made using CAT5 non-crossover cable.
Each inverter needs to be assigned a status — “master” or “slave”. The master is the primary and most
heavily used unit. Slave inverters provide assistance when the loads are more than the master can
handle alone. Programming involves using the MATE3 to assign a status and stacking value to the
inverter on each port.
Figure 7 OutBack HUB4 and MATE3
IMPORTANT:
 The master inverter must always be connected to port 1 on the HUB product.
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.
 All stacked Radian inverters must have the same firmware revision. If inverters are
stacked with different firmware revisions, any unit with a revision different from the
master will not function. The MATE3 will display 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.
 Neither the GS8048A nor the GS4048A can stack with the previous model GS8048.
The GS8048 can share a HUB Communications Manager with the current models
2 The port designations for the mismatched inverters are listed here.
Additional Ports Port 1 MATE Port
HUB4
MATE3