Power source – U.S. Sunlight SC12 Solar Controller User Manual
Page 6
Refer to this summary to interpret the LCD display and the fan’s operating status:
LCD Display
House
Power
Solar
Power
Fan
Operation Summary
(Blank)
ON
ON
• Solar power is available
• Fan is running
(Blank)
ON
OFF
• Solar power is available
• Fan is not running
• Attic Temperature is <80°F
• Thermo Switch could be ON
• To run fan, switch Thermo Switch to
OFF then press the Status button twice
ON
(Blank)
ON-Intermittent
• Solar power is not available
• Fan is powered by house electricity
• Fan is running intermittently, currently
in the 8-min ON mode of the 6-hour
cycle
Summary:
Note that the primary power source is always SOLAR. If solar power is not available during the daytime, the primary
power source will switch to house electricity (if the Controller Box is connected to house electricity) for up to 6 hours or
until solar power becomes available.
Primary Power Source
Solar Fan with Solar Controller
WITHOUT AC Adapter connected
Solar Fan with Solar Controller
WITH AC Adapter connected
Daytime - with sufficient solar power
Solar power
Solar power
Evening after sunset
No power available
Intermittent house electricity for 6 hours
1. Whenever available, solar power is the default power source. On a typical day with proper sunlight, the fan will
operate until sunset.
2. If solar power is not available, the fan will not operate unless the Solar Controller is installed with the AC Power
Adapter connected to house electricity. The fan will continue operation in the following pre-set mode for 6 hours:
i. ON for 8 minutes and OFF for 22 minutes in a 30-minute period. This is the most effective air circulation
frequency to keep the attic temperature close to the outside temperature
ii. The fan will run for a maximum of 6 hours on intermittent house electricity.
iii. The fan will run on solar power whenever solar power becomes available again.
iv. After 6 hours of running on intermittent house electricity, the fan will be turned off for up to 12 hours, then
turned back on, assuming solar power is not available during this period of time.
Power Source