Outback Power Systems GFX International Series Installation Manual - Manual (Page 31)

Installation
900-0111-01-00 Rev B 29
Parallel Stacking (Dual-Stack and Larger)
In parallel stacking, two or more inverters are stacked to create a single, common 230 Vac bus.
¾ All inverters share a common input (AC source) and run loads on a common output.
¾ 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.
Figure 20 Example of Parallel Stacking Arrangement (Three Inverters)
When installing a parallel system, the following rules must be observed.
¾ Parallel stacking requires a system display and a HUB.
¾ 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.
¾ The master must be connected to port 1 of the HUB. Other inverters must not be selected as master.
¾ All slave inverters, regardless of quantity, should be selected as OB Slave L1 during programming.
¾ All overcurrent devices must be sized for 30 Aac or less.
¾ All wiring must be sized for 30 Aac or more.
¾ All output circuit breakers must be sized appropriately for loads and inverter wattage.
¾ All inverters must be of the same model.
¾ The AC input (generator or utility grid) must be 230 Vac at 50 Hz (single-phase).
¾ 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.
3.9 kVA
230 Vac
1.3 kVA 230 Vac 1.3 kVA 230 Vac 1.3 kVA 230 Vac