Specialty Concepts SCT - Manual (Page 11)

O P E R A T I O N
The SCT (without the PHOTO SENSOR) detects sundown by sensing the voltage drop on the
array and turns the light on, then lets it run for the pre-selected period
When the output voltage from the solar array falls to .5 volts, the SCT will turn on the load and
begin its timing period. When the time period is complete, the load will turn OFF and the TIME
BASED LED will remain on to indicate that the timing cycle has been completed. Sunrise will
reset the unit and the TIME BASED LED will again begin pulsing.
To simulate sundown and a timing cycle, disconnect the array from the ARRAY (+) terminal.
After a delay of about 10 to 15 minutes, the load should turn on, and the SCT will operate in its
normal manner. Reconnect the ARRAY (+) terminal to the array and the load should immediately
go off and the SCT should be reset.
T R O U B L E S H O O T I N G
LIGHT (OR LOAD) WILL NOT TURN ON:
1) Check operation of light independently of the timer circuit to insure that it is operational.
2) Test the timer by removing the connection to "ARRAY +" and waiting about 15 minutes. Note:
The SCT must have a light or load connected for the test. The output will not register on a
meter.
3) Test for high ambient light conditions at the array. If array voltage does not drop below .5 volts,
the timer will not turn the load lights on. Use the photocell accessory mounted in a
shielded location to get the light to turn on in high ambient lighting situations.
LIGHT TURNS ON DURING THE DAY:
1) The SCT monitors array voltage to determine sundown. Some shunt controllers shunt the array
for longer than the 15 minute delay of the timer, indicating sundown. The alternatives are
to use a different controller (the ASC series of controllers manufactured by Specialty
Concepts is well matched with the SCT) or to use the photocell accessory to monitor
daylight.
LIGHT WILL NOT TURN OFF:
1) Check to see that the light negative is not connected to battery negative, or ground. The SCT
is a positive ground device, so it switches the negative leg of the load circuit.
LIGHT TURNS ON TOO SOON OR TOO LATE:
1) Use the photocell accessory to adjust sensitivity to ambient lighting.