Blue Sky SC30 - Manual (Page 4)

Blue Sky Energy – Sun Charger 30
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PRODUCT DESCRIPTION
The Sun Charger 30 is a 30 amp 12 volt Pulse Width Modulated (PWM) photovoltaic (PV) battery charge controller. The SC30’s sophisticated 3-stage
plus equalization charge control system improves battery performance and life while minimizing battery maintenance. The unit is electronically protected
against voltage transients, over temperature, over current, short circuit, swapped battery & PV, and reverse battery & PV polarity. A current limit feature
minimizes the likelihood of overload by limiting average output current to 30 amps maximum during periods of unusually high PV power production.
A very low power LED display is provided to monitor battery voltage and PV charge current. The display system also includes a resettable amp-hour counter
which computes total PV amp-hours produced.
PART NUMBERS AND OPTIONS
• SC30 ................... Sun Charger 30 solar charge controller • 930-0022-20 ..................... Optional battery temperature sensor
• SC30-LVD ........... SC30 with Load & Lighting control drive signal • 720-0011-01 ..................... Optional wall mounting box, black powder coated
(-LVD version by special order only, contact factory)
OPERATION
Basic charge control operations are fully automatic and require no operator intervention. When sufficient PV power is available the SC30 will switch to
a Charge ON state and begin charging the battery. The particular charge mode the SC30 will operate in will vary depending on the needs of the battery and
12 volt electrical system, and available PV charge current. When insufficient PV current is available to charge the battery the SC30 will switch to a Charge
Off state. At night when the SC30 is in a Charge Off state the PV array is disconnected from the battery to prevent unwanted current drain. There is a 5
second turn-on delay, and a 30 second turn-off delay.
¾ The SC30 operates on battery power, not PV power. Insure that voltage on the battery terminals of the SC30 is always the
same as actual battery voltage within a few 10 ths of a volt for proper operation. A battery must be connected with a minimum
voltage of 9 volts for the unit to operate. Note that the front panel serves as a heatsink for power control devices and may
become quite warm during normal operation.
¾ CAUTION: Do not disconnect the battery while the SC30 is in a Charge ON state. A healthy battery is a key component of PWM
charge voltage control and provides charge voltage filtering. Sudden removal of the battery while the SC30 is charging will produce
voltage spikes at the SC30’s battery terminals which may damage 12 volt appliances still connected to the SC30.
IF THE BATTERY MUST BE DISCONNECTED, REMOVE PV POWER FIRST.
CHARGE STATUS INDICATION
Present charge status of the SC30 is indicated using two charge status LED’s, Absorption & Float. If net battery charge current is greater than about 3 to 5
amps per 100 amp-hours of battery capacity the charge status indicator can provide a rough indication of battery state of charge.
CHARGE STATUS
CHARGE STATUS LED’s CHARGE MODE APPROXIMATE CHARGE LEVEL
ABSORPTION & FLOAT OFF CHARGE OFF
ABSORPTION & FLOAT ON BULK <70% FULL
ABSORPTION ON – FLOAT OFF ABSORPTION 70% - 95% FULL
ABSORPTION OFF – FLOAT ON FLOAT FULLY CHARGED
ABSORPTION & FLOAT
ALTERNATELY BLINKING
EQUALIZE
TABLE 1
DIGITAL DISPLAY
When the SC30 first boots and completes self-test, the VOLT/AMP display mode is active. This mode displays Battery Voltage continuously if the
SC30 is in a Charge Off state, or alternates between Battery Voltage & Output Charge Current if the SC30 is in a Charge On state. The AMPS indicator in the
upper left of the display will be on whenever current is displayed. To provide good readability during the day yet minimize the likelihood of the display being
objectionably bright at night an automatic night time dimming feature is provided which dims the display when the SC30 is in a Charge Off state.
Other display modes may be selected using the Display Select push-button. Each brief press of Display Select selects the next display mode as shown on
the front panel graphic of Figure 1. VOLT shows Battery Voltage, AMP shows Output Charge Current, and AMP-HRS shows total PV Amp-Hours produced since
the amp-hour counter was last cleared. One more brief press after AMP-HRS turns the display off completely. Each brief press of Display Select moves to the next
display mode in a continuous loop as shown on the front panel graphic. Note that the Amp-Hours are shown in whole numbers without a decimal point.
SOLAR CHARGE AMP-HOUR COUNTER
The battery essentially serves as a “storage tank”, with the battery storing electrical energy in units referred to as amp-hours. Amp-hours are
computed by multiplying current in amps X time in hours. For example 20 amp-hours may be a current of 10 amps flowing for 2 hours, or may be 1 amp
flowing for 20 hours. The battery receives and stores amp-hours when being charged, and then delivers those stored amp-hours when being discharged. As
a broad approximation typical lead-acid batteries including GEL and AGM are about 95% efficient in absorbing charge amp-hours.
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