Outback Power Systems GS8048 Operator Manual - Manual (Page 25)

Operation
900-0020-01-00 Rev B 23
Repeated Silent
The unit re-enters the Silent stage as it did previously. The unit remains on the AC source, but the
charger is inactive.
Target point: Re-Float Voltage setting. The default set point is 50.0 Vdc.
The unit will continue cycling between Float and Silent for as long as the AC source is present.
However, if excess DC power is available and the battery voltage rises above the Sell Voltage set
point, the unit can resume Offset activity as described on page 21.
The unit can only enter Offset when none of the timers are active. If any of the timers have accumulated
time while in Silent, the unit will enter the highest stage with accumulated time and proceed from
that point.
Figure 5 Repeated Charging Cycles
New Charging Cycle
If the AC source is lost or disconnected, the unit will return to inverting mode if enabled. The battery
voltage will begin to decrease due to loads or natural loss. When the AC source is restored, the
inverter will return to the charging cycle. If the batteries drop below the Rebulk voltage (see below),
the inverter will restart the cycle, beginning at Bulk stage. If the batteries do not drop below Rebulk,
the charger will not enter the Bulk stage and will return to its previous stage.
New Absorption Stage
When entering the second stage, Absorption, the charger will not necessarily run through its full
duration. The timer will count down whatever time remains from the previous cycle, or whatever time
it has accumulated since then.
Absorption Timer
The Absorption timer does not reset to its maximum like the Float timer does. Instead, the timer
counts upward (gaining time) whenever the battery voltage drops below the Rebulk point. This
means that the Absorption period may not always be the same, depending on how much time it
has acquired.
The Rebulk voltage is 48.8 Vdc. This is a fixed setting and cannot be changed. For as long as the
inverter remains below this voltage, the Absorption timer will gain an equal amount of time. This
dictates the duration of the Absorption stage. Note that in Figure 5, the duration of time spent below
the Rebulk voltage is the same as the subsequent Absorption period (as shown by the small arrows).
No
Charge
Bulk
Absorption
Offset
AC Loss
Offset
Bulk
Absorption
Silent
Float
Float
Timer
Absorption Set Point
Sell Set Point
Float Set Point
Voltage
Time
Rebulk Point
Refloat Set Point