Product Manual

40
DIVERSION CHARGE CONTROL
41
MORNINGSTAR CORPORATION
6.0
The table below summarizes the major parameters of the standard diversion
battery charging algorithms. Note that all the voltages are for 12V systems
(24V = 2X, 48V = 4X).
All values are 25ºC (77ºF).
A. B. C. D. E. F. G.
Time Max.
DIP PWM Until Time Equalize Equalize
Switches Absorp. Float Float Equalization in Equal. Interval Cycle
(4-5-6) Voltage Voltage (hours) Voltage (hours) (days) (hours)
off-off- off 13.8 13.6 4 14.1 3 28 3
off-off-on 14.0 13.6 4 14.3 3 28 3
off-on-off 14.2 13.6 4 14.5 3 28 4
off-on-on 14.4 13.6 4 14.7 4 28 4
on-off-off 14.6 13.7 4 14.9 4 28 5
on-off-on 14.8 13.7 4 15.1 4 28 5
on-on-off 15.0 13.7 4 15.3 4 28 5
on-on-on Custom Custom Custom
Table 6.3 Standard Diversion Charging Programs
A. PWM Absorption Voltage - This is the PWM Absorption stage with
constant voltage charging. The PWM absorption voltage is the maximum battery
voltage that will be held constant.
B. Float Voltage - When the battery is fully charged, the charging voltage
will be reduced to the float voltage for all diversion settings. The float voltage and
transition values are adjustable with the PC software.
C. Time Until Float - This is the cumulative time in PWM before the battery
voltage is reduced to the float voltage. If loads are present during the PWM
absorption, the time to transition into float will be extended.
D. Equalization Voltage - During an equalization cycle, the charging voltage
will be held constant at this voltage. Equalizations are manual, and can be selected
for automatic
(See Section 4.4.1) .
E. Time in Equalization - Charging at the selected equalization voltage will
continue for this number of hours.
F. Equalization Interval - Equalizations are typically done once a month.
The cycles are 28 days so the equalization will begin on the same day of the week.
Each new cycle will be reset as the equalization starts so that a 28 day period will
be maintained.
G. Maximum Equalization Cycle - If the battery voltage cannot reach the
equalization voltage, the equalization will terminate after this number of hours to
avoid over gassing or heating the battery. If the battery requires more time in
equalization, the manual pushbutton can be used to continue for one or more
additional equalization cycles.
6.3.1 Battery Charging References
The diversion load battery charging is similar to conventional solar charging. Refer
to the following sections in this manual for additional battery charging information.
4.1 Four stages of charging (applies to diversion)
4.3 Temperature Effects and Battery Voltage Sense
4.4 Equalization
4.5 Float
9.0 Battery Information
6.4 Selecting the Diversion Load
It is critical that the diversion load be sized correctly. If the load is too small, it
cannot divert enough power from the source (wind, hydro, etc). The battery
will continue charging and could be overcharged.
If the diversion load is too large, it will draw more current than the rating of
the TriStar. The controller’s overload protection may disconnect the diversion
load, and this will result in all of the source current going to the battery.
CAUTION: The diversion load must be able to absorb the full power output of the
source, but the load must never exceed the current rating of the TriStar controller.
Otherwise, the battery can be overcharged and damaged.
PRUDENCE : La charge de diversion doit être capable d’absorber toute la puissance
de sortie de la source, mais la charge ne doit jamais dépasser l’intensité nominale
du contrôleur TriStar, pour ne pas surcharger et endommager la batterie.
7.4.1 Suitable Loads for Diversion
Water heating elements are commonly used for diversion load systems. These
heating elements are reliable and widely available. Heating elements are also easy
to replace, and the ratings are stable.
NOTE: Do not use light bulbs, motors, or other electrical devices for diversion loads.
These loads will fail or cause the TriStar to disconnect the load. Only heating
elements should be used.
REMARQUE : N’utilisez pas d’ampoules, de moteurs ou d’autres appareils
électriques pour les charges de diversion. Ces charges ne fonctionneront pas ou
provoqueront une déconnexion de la charge par le TriStar. Seuls les éléments de
chauffe doivent être utilisés.
Water heating elements are typically 120 volts. Elements rated for 12, 24
and 48 volts are also available, but more difficult to source. The derating
for 120 volt heating elements is discussed in 6.4.3 below.
6.4.2 Definition of Terms
Maximum Source Current:
This is the maximum current output of all the energy sources (hydro, wind,
solar, etc.) added together. This current will be diverted through the TriStar
to the diversion load.
Maximum Battery Voltage:
This maximum voltage is the PWM regulation voltage selected with the DIP
switches, plus the increase with an equalization, plus the increase due to
lower temperatures. The highest battery voltage is commonly 15, 30 and
60 volts for 12-, 24- and 48-volt systems.
Peak Load Current:
At the maximum battery voltage, this is the current the diversion load will