You have almost answered your own question. If the photosensor is active, it must read a light level to know if it needs to turn on the lights. It reads the
calculated daylight at the sensor and calculates the electric lighting to add to reach a set lighting level?.
Ned Lyon, P.E. (MA, WV)
Staff Consultant
SIMPSON GUMPERTZ & HEGER
781.907.9000 main
781.907.9350 direct
617.285.2162 mobile
781.907.9009 fax
www.sgh.com
From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx]
Sent: Monday, February 01, 2016 3:26 PM
To: yahoogroups
Subject: [EnergyPlus_Support] Photosensors
When photosensors are activated in EnergyPlus, the output daylight illuminance in each zone is available. How does EnergyPlus separate daylight illuminance
from electric illuminance? In a zone both electric lights and daylight are available a photosensor can tell the combined illuminance not separately daylight illuminance.