Blue Sky Solar Boost 3000i - Manual (Page 6)

Blue Sky Energy – Solar Boost 3000i
5
2-STAGE CHARGE CONTROL
The 3000i may be configured for 2-stage charge control if desired by setting the Float Charge Voltage to OFF.
OUTPUT CURRENT LIMIT
Should conditions be present where the PV modules are able to produce more than 30 amps of output current with 36 cell PV modules, or 22 amps
with 60 cell PV modules, the 3000i will automatically limit output current to this value. Note that when current drops and the 3000i exits current limit it will first
enter Absorption on its way back to Bulk even though battery voltage may be below the Absorption Charge Voltage setpoint.
¾ WARNING: Current limit should be thought of as transient PV over current protection and not a normal mode of operation. If
the 3000i enters 30 amp or 22 amp current limit on a regular basis it is possible that excessive PV power is connected. Confirm
that the PV modules do not exceed ratings shown in the Selecting PV Modules section.
OPTIONAL TEMPERATURE COMPENSATION
The charge voltage required by batteries changes with battery temperature. Temperature compensation of charge voltage enhances battery
performance and life while decreasing battery maintenance. Temperature compensation of charge voltage can be provided using the optional battery
temperature sensor (BSE p/n 930-0022-20). The default compensation factor of –30mV/
°C (–5.00mV/°C/cell) is typically appropriate for most lead-acid
chemistry batteries including GEL and AGM. If a proper temperature sensor signal is not detected the 3000i will operate as if battery temperature is 25 °C.
FACTORY DEFAULT CHARGE VOLTAGE SETPOINTS -VS.- BATTERY TEMPERATURE
FIGURE 2
EQUALIZATION
¾ WARNING: Not all batteries can be safely equalized. Equalization should be performed only on vented liquid electrolyte
lead-acid batteries. Always follow battery manufacturers recommendations pertaining to equalization. Equalization applies a
relatively high charge voltage producing significant battery gassing. Prior to performing equalization disconnect equipment that
cannot tolerate the high equalization voltage which is temperature compensated as shown above.
Equalization is a controlled overcharge used to bring all battery cells up to the same specific gravity and state of charge. The 3000i may be configured to
perform an automatic equalization on periodic basis, or a manual equalization. Since sealed batteries should not be equalized the factory default settings have
Equalize Enable (EqE) set to OFF to disable automatic or manual equalization. Equalization may be enabled by setting Equalize Enable to ON as described in the
Charge And Load Control Settings section. When an equalization cycle is being performed the Float and Absorption charge status LED’s will alternately blink.
With equalize enabled the 3000i will perform an automatic equalization at the factory default settings of 15.2V for 2 hours every 30 days which is typically
suitable for most flooded lead-acid batteries. When set for automatic equalization the cycle will begin when the set number of days since the last equalization has
elapsed, and the charge control system has switched to Float. When set for manual equalization (Eqd set to 00) an automatic equalization will not occur. Whether
set for automatic or manual the process may be started or stopped manually by pressing the Display Select push-button for 20 seconds.
Once equalization has started the equalize timer will not count down unless battery voltage is at the equalize voltage setpoint which is temperature
compensated as shown above. Therefore obtaining a proper 2 hour equalization will require longer than 2 hours to complete depending on available charge
current. Note that at least 3.5 amps of net charge current per 100 amp-hours of battery capacity is typically required to properly equalize a battery. If equalization
does not complete during the charging day it will resume where it left off the next charging day, but will automatically cancel if unable to complete within 24 hours.
The equalize day counter is reset whenever an equalization cycle is started.
MAXIMUM SETPOINT VOLTAGE LIMIT
The maximum setpoint voltage limit places a maximum limit or ceiling on the charge voltage setpoint used by the 3000i in all charge modes to prevent
inverters or other equipment from shutting down due to excess voltage. Regardless of initial setpoints, charge mode or temperature compensation the 3000i
will not use a charge voltage setpoint greater than the maximum setpoint voltage limit (uPr) factory set to 15.5V. Note that voltage may briefly exceed this
value by 0.1 – 0.2V as the system responds to sudden changes in load or PV power.