Where should a transformer with a photocell be installed?

• A. Where there is ample sun
• B. Out of plain view
• C. Behind a shrub
• D. On the east wall of a structure

Answer: (A)

Photocell-based transformers need ambient daylight to decide when to turn lights on or off. If the sensor sees bright daylight, it stays off; as daylight fades, it allows the lights to come on. That only works reliably if the sensor is in direct sun. Placing it where it’s out of view or behind a shrub blocks sunlight from reaching the sensor, causing it to misread the light level and operate erratically. Relying on an east-facing wall might provide morning sun, but it can still be shaded later, leading to inconsistent dusk-to-dawn performance. So the best placement is where there is ample sun, ensuring accurate and reliable day/night sensing.