Outback Power Systems GFX Series Inverter/Charger Installation Manual - Manual (Page 30)

Installation
28
900-0113-01-00 Rev A
Classic Series Stacking (Dual-Stack)
In “classic” series stacking, two inverters create two separate 120 Vac output phases (“legs”). One leg
is the master. The other is the slave, which creates a 120 Vac output that is intentionally 180° out of
phase with the master. Each of these legs can be used to power a separate set of 120 Vac loads.
Collectively they form a “split-phase” configuration. This configuration produces 240 Vac, which can
be used to power 240 Vac loads when both inverters work together.
 The two legs operate independently of each other. Each can run in independent Search mode if desired.
 The 120 Vac loads on each leg cannot exceed a given inverter’s wattage. The second inverter cannot assist.
 Only two inverters, one per phase, may be installed in a classic series arrangement.
1.3 kVA
120 Vac
2.6 kVA
240 Vac
1.3 kVA
120 Vac
1.3 kVA 120 Vac
1.3 kVA 120 Vac
Figure 20 Example of Classic Series Stacking Arrangement
When installing a series inverter system, the following rules must be observed.
 Series stacking requires a MATE and HUB.
 The inverter that is mounted physically lowest is always the master and is programmed as Master. (See the
system display manual for programming.) 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 HUB. Other inverters must not be selected as master.
 The slave inverter must be selected as a Classic Slave during programming.
 All inverter wiring and input breakers must be sized for 60 Aac or less.
 All output breakers must be sized appropriately for loads and inverter wattage.
 Both inverters must be of the same model.
 The AC input (generator or utility grid) must be 120/240 Vac (split-phase).
 When wiring the AC source to the inverters, local codes may require the inverter breakers to be located at
the bottom of the main panel. This prevents overloading of the AC bus.