Specialty Concepts SCS/90 - Manual (Page 13)

M O N I T O R I N G
"CHARGING" LIGHT: The "CHARGING" light will be on when the controller is in the full charge
mode. In this mode, the charging relay is closed, connecting the array directly to the
battery. This light should go on first thing in the morning, and will go off if the battery
reaches the Full Charge Termination voltage set-point. If the light is off after morning, the
batteries have reached the full charge voltage some time that day. The light may go on
again if the battery drops below the reconnect voltage and the controller goes into the full
charge mode again. It is not uncommon for the light to remain on, for several hours after
dark. Refer to the operation section for details on controller operation.
"LOAD DISCONNECTED" LIGHT: When the "LOAD DISCONNECTED" light is on, the low-
voltage disconnect (LVD) circuit is activated and any DC loads connected to the "Load"
terminals will be disconnected. This occurs at the LVD voltage set-point. The light will go
out when the voltage rises above the reconnect voltage and the load is reconnected
automatically, or if the reset switch is pushed to “MANUAL RESET" or “NO LVD". Refer to
the operation section for details on LVD operation.
DIGITAL DISPLAY: The Digital display on the front of the SCS provides metering of four
parameters, selected by a slide switch to the right of the display, labeled: 1, 2, 3, 4.
“SWITCH POSITIONS”
POSITION 1 - "BATTERY VOLTAGE": This displays the system battery voltage. The
battery voltage is a general indication of battery condition, or capacity. Battery
voltage will change when the battery is being charged and discharged, with the
amount of change depending on the amount of charge current or discharge current.
A fully charged battery that is not being charged or discharged will be at about 12.6-
12.8 volts (12 volt battery). The normal range of a 12 volt battery is about 11 to 15
volts. A voltage below 11 volts would indicate a dead battery, and over 15 volts
indicates an overcharging battery. It is best to keep the batteries above 11.5 and
below 14.8 for maximum battery life and performance.
POSITION 2 - "ARRAY CURRENT": This displays the amount of current the solar
panel is generating. Any current generated by the solar panels will be used first to
operate any loads that are on, and any left over will go into the battery for charging.
The array current reading can be used to optimize the array tilt angle by moving the
array (if possible) and noting when current is maximum. Consult the panel supplier
or literature for rated output to see what the output current should be for the total
number of panels in the system under ideal conditions. Ideal conditions would be a
bright sunny day, with the panel aimed right at the sun and no shadows or dirt on
the panel.
POSITION 3 - "AUX CURRENT": This position is used to calibrate the alarm voltages.
See VOLTAGE ALARMS section.
This position can also be used to display the reading from an external shunt. This
reading could be used for a charger or alternator or for monitoring loads such as a
DC source center or an inverter. Refer to INSTALLATION INSTRUCTIONS: ”AUX
CURRENT CONNECTION” (step #16) (above).
POSITION 4 - "LOAD CURRENT": This position displays the current being consumed
by any DC load connected to the load terminals of the SCS. This position will not
monitor current to loads connected directly to the battery, such as an inverter.