If power is lost or removed during a photocell's on/off period, it may be necessary to disconnect and reconnect the photocell to reset its control of the fixtures. Otherwise, the fixtures the photocell controls may stay on.
When disconnecting the photocell, leave it disconnected for thirty seconds. This will give the LCD system time to register a light level below any threshold, essentially zeroing out its reading.
After the time period, reconnect the photocell. If the registered light level is high enough and programming is correct, the photocell will turn off whatever fixtures it should be controlling.