Specialty Concepts SC3/20 - Manual (Page 17)

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 problems with a solar system. If a
possible problem with the SC3/20 is suspected based on the observations and notes in the
“MONITORING” section, refer to the chart titled SC3/20 PROBLEMS and the case note for each
condition. If you feel your batteries are not being adequately charged or are consistently being
over-charged, refer to the section BATTERY PROBLEMS. If you feel that the solar panels are not
performing adequately, refer to the section SOLAR PANEL PROBLEMS. You may be asked to
perform the FUSE REMOVAL TEST or other tests to assist with the diagnosis. The problem
sections will often refer back to the HELP NOTES section.
HELP NOTES :
Normal Conditions and Common Problems
NORMAL CONDITIONS:
1. CHARGING MAY NOT NEED TO STOP - The SC3/20 is designed to prevent over-charging
of the battery. It does this by charging the batteries up to about 14.3 volts. It will then turn
the solar panel off. Charging will resume when the battery voltage drops to about 13.0 volts.
If the charge current is not strong enough to over-charge the battery, the controller may not
need to 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 not have as much capacity when cold.
PROBLEM CONDITIONS:
5. 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.
6. 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 or dirt on the panel.
7. PROBLEMS WITH THE BATTERIES - There are a few problems with batteries that can
cause the system to malfunction. When batteries get old and start to fail, they do not accept
charge current or deliver load current very well, and in fact act like a very small battery. A
small amount of charging will cause the voltage to rise prematurely, and any discharge will
make the voltage fall rapidly. This can be confusing to the controller and to anyone
watching the battery voltage. 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.