Xantrex Technology 815-3012 Parallel Stacking, Series Stacking, Introduction, 97-0019-01-01

Freedom SW 3K2K InvChg Owners Guide.book Page 3 Wednesday, October 9, 2013 1:34 PM

	Introduction
Manual Equalization Over a period of time, the cells in a flooded	Stacking
battery can develop uneven chemical states. This can result in a weak	Supports stacking of two inverter/chargers to increase capacity. This also
(undercharged) cell which, in turn, can reduce the overall capacity of the
battery. To improve the life and performance of a non-sealed, flooded	requires the installer to select a Master and Slave in order for the inverters
battery, the Freedom SW’s multi-stage charging cycle includes a manual	to stack. Two configurations of stacking are supported: Parallel stacking
equalize mode that can be used, if recommended by the battery	and Series stacking.
manufacturer.

Dead Battery Charging Another feature that the Freedom SW includes is dead battery charging. The Freedom SW—unlike many chargers—has the ability to recharge batteries even if the battery voltage is very low, i.e., as low as 3 volts.

Load Management The Freedom SW has a built-in transfer relay that connects your inverter output or AC input from the utility grid or generator to your loads. Because the usual AC power sources such as campground outlets or small generators often have limited current availability, having the capability to manage your AC loads is extremely valuable. The Freedom SW provides a number of features to facilitate this:

Parallel Stacking

Parallel stacking allows two inverter/chargers to operate in parallel thereby doubling the capacity in inverter mode. The two inverters communicate over the network and intelligently share the load and to balance the load between the two units. The Master Freedom SW broadcasts pulses on the Xanbus network to synchronize operation between the other paralleled unit. When AC loads are present, both units produce power, effectively sharing the load. When Search mode is enabled, only the Master unit produces the AC output.

•The charger is power factor corrected to use AC current as efficiently as possible. Minimizing the AC current used by the charger means more current is available for your AC loads.

•Freedom SW has a power share feature which prioritizes your AC loads by reducing the charge current and maintaining the total input current to less than the breaker setting.

Occasionally, AC input sources have low voltage. To avoid loading these weak sources any further, the charger automatically reduces its AC current draw as the AC voltage approaches the minimum acceptable level.

Series Stacking

Two units can be configured to generate 120/240 Split-phase power for load configurations that require both 120 and 240 volts. In this configuration, the AC source must be split-phase as well.

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