Installation Guide

49 TriStar MPPT-600V-TR Operator's Manual
48
Operation
Absorption Extension
1:00 2:00 3:00 4:00 5:00 6:00
50.00 V
Bulk
Extended
Absorption
FloatAbsorption
Absorption Extension Voltage
time (hrs)
Figure 4-3. Absorption extension charging prole.
If battery voltage discharges below 50.00 Volts the previous night, Absorption charging will be
extended on the next charge cycle as shown in gure 4-3 above. 30 minutes will be added to the
normal Absorption duration.
Float Time-Out
1:00 2:00 3:00 4:00 5:00 6:00
Float V
Bulk
Float
Absorption
Absorption
60 mins.
below Float
Voltage
time (hrs)
Bulk
Figure 4-4. Float exit time-out charging prole
After entering Float stage, the controller will only exit Float if the battery voltage remains below
Float voltage for 60 cumulative minutes. In gure 4-4, a system load turns on at 3:30 hrs when
the controller is in Float stage, and runs for one hour, until 4:30 hrs. The load current draw
is larger than the charge current, causing battery voltage to drop below Float voltage for 60
minutes. At that point, the controller returns to Bulk charging, and then Absorption stage once
again. In this example, a load runs continuously for 60 min. However, because the Float exit
timer is cumulative, multiple momentary load events that pull the battery voltage below Float
voltage for a combined 60 minute duration will also force an exit from the Float stage.
Float Cancel Voltage
1:00 2:00 3:00 4:00 5:00 6:00
49.20 V
Bulk
Absorption
Float Cancel Voltage
time (hrs)
Float cancelled this charge cycle
Figure 4-5. Float cancelled charging prole
If the battery bank discharges below 49.20 Volts the previous night, Float charging stage will be
cancelled for the next charge cycle. Figure 4-5 above illustrates this concept. At 0:00 hrs (dawn),
battery voltage is below the Float Cancel threshold voltage. The diagram shows where Float
stage would have occurred if Float was not cancelled.
Equalize Time-Out
1:00 2:00 3:00 4:00 5:00 6:00
Absorp. V
Bulk
Float
Equalize
Equalize timeout
time (hrs)
Equalize V
Figure 4-6. Equalize time-out charging prole
The charging prole in gure 4-6 shows an Equalize Time-out event. The time-out timer begins
as soon as battery voltage exceeds the Absorption voltage set-point. If there is insufcient charg-
ing current or system loads are too large, the battery voltage may not reach the Equalize set-
point. Equalize Time-out is a safety feature that prevents high battery voltage for extended peri-
ods of time which may damage the battery.