Specialty Concepts SC3/15 - Manual (Page 13)

T R O U B L E S H O O T I N G
The following section can assist in the troubleshooting of a solar system. Please review the section
below titled “HELP NOTES” which lists some common situations with a solar system. Within this
section, you may be asked to perform a test using a voltage multi-meter to assist with the diagnosis.
•
SC3/15 Charge Controller: - If a possible problem is suspected based on the observations of the SC3/15
controller, refer to the chart titled SC3/15 PROBLEMS and the “SC3/15 Note” for each condition on the
following pages.
•
Battery: - If you feel your batteries are not being adequately charged or are consistently being over-charged,
refer to the section BATTERY PROBLEMS.
•
Solar Panels: - If you feel that the solar panels are not performing adequately, refer to the section SOLAR
PANEL PROBLEMS.
NORMAL CONDITIONS:
1. NORMAL OPERATION: CHARGING / NOT CHARGING - Depending on your system, the SC3/15 may
go for long periods of constant charging or long periods with no charging. The SC3/15 is designed to
prevent over-charging of the battery. It does this by stopping the charging at about 14.4 volts. It will
then turn the solar panel off. Charging will resume when the battery voltage drops to about 13.05 volts.
If the battery is fully charged, additional charging may not be needed. If the charge current is not strong
enough to over-charge the battery, the controller may not turn the panel charging off.
2. BATTERY WATER LOSS - Vented batteries will need some water from time to time in the natural
course of events. Minor water loss is not a problem; just top up the level when needed. Excessive
water loss (a quart or more in a period of a month) may indicate a more serious problem.
3. BATTERY GASSING - In vented batteries, some gassing is good. Gassing stirs up the battery acid
and allows the battery to fully charge. A little bubbling in the batteries is not necessarily a problem.
See BATTERY WATER LOSS above.
4. TEMPERATURE - Temperature can affect the performance of batteries. They will tend to over-charge
easier when hot, and will have a lower state of charge when cold.
5. METER ACCURACY - The meters on the SC3/15 are intended to be an indication of system
performance, like a gas gauge in a car. They are not intended for exact measurements. The meters
can be off by as much as 3/4 volt or 3/4 amp.
PROBLEM CONDITIONS:
6. SYSTEM IS NOT SIZED CORRECTLY - The solar system batteries will tend to be under-charged if the
solar panel array is too small, or if the battery bank is too small, or if the usage is too high.
7. PROBLEMS WITH SOLAR PANELS - Solar panel output is dependent upon the amount of sun-energy
reaching the panel. This can be seriously affected by panel angle of orientation, minor shading, high
level haze (barely visible) and dust on the panel. At the time of installation, a solar array can have an
incorrect series-parallel configuration for the proper system voltage and current. A panel can also
become less productive or defective over time. TEST: Disconnect the array(+) connection on the
SC3/15, and measure the voltage directly at the array using the positive and negative wires. In sunny
conditions, this should be 18-24 volts. A lower voltage could indicate a problem with the solar panels.
8. PROBLEMS WITH THE BATTERIES - At the time of installation, a battery bank can have an incorrect
series-parallel configuration for the proper system voltage and current. When batteries get old and
start to fail, they do not accept charge current or deliver load current very well, and begin to act like a
very small battery. A small amount of charging will cause the voltage to rise quickly, and any discharge
will make the voltage fall rapidly. Another condition, a shorted battery cell, can cause the system to
charge continuously without any appreciable increase in overall battery voltage. The cells that are not
shorted will tend to gas heavily. If the condition of the battery is suspect, a battery capacity test is
recommended.
HELP NOTES : ( Normal Conditions and Common Problems