Stacking Features
Search Mode Operation in Parallel Stacking
When two inverter/chargers are stacked for parallel operation, search mode behavior on the Slave unit is modified and is dependent on how much total load is on the system.
Disabling Search Mode on the Master Unit
In parallel stacking, search mode on the Master unit will not function properly. When the Master sends out a load search pulse, a small current also flows into the output of the Slave unit since the two outputs are in parallel. This Master unit falsely detects a load causing erratic search mode operation. For this reason, it is highly recommended to disable search mode on the Master unit in a parallel stacking system.
Setting Search Mode on the Slave Unit
The Slave unit will behave in one of two ways depending on whether its search mode is enabled or disabled.
Search mode enabled This is the recommended mode for parallel stacking and it helps minimize battery draw. The Slave unit continuously monitors the output of the Master unit. If the Master unit has more than 60% of the rated load (for example, 2100 watts on Freedom SW
the two will share the load equally. Should the load on the Master drop below 20% of rated load (700 watts for Freedom SW 3524- 230), the Slave unit disengages and returns to a waiting state.
Search mode disabled The Slave unit operates continuously along with the Master unit and shares the load.
Wiring Schematic
NOTE: Please refer to the Stacking Configuration sheet that shows the wiring schematic employed between two Freedom SW 230V inverter/chargers that are stacked in parallel.
IMPORTANT: Follow the same guidelines in “Installing the Inverter/Charger” on page 17 when choosing cables and/or wires for AC and DC connections.
FIRE, ELECTRICAL SHOCK, AND ENERGY HAZARDS
Make sure all wiring being used to make stacking configurations between inverter/chargers is disconnected (physically or by opening the breaker) from all electrical sources before handling. All wiring must be done in accordance with local and national electrical wiring codes.
Failure to follow these instructions will result in death or serious injury.
46 | Freedom SW 230V Installation Guide |