9
Set the Lighting Set points:
The controller will turn the light on and off or will
modulate the dimming output (if enabled) based on the measured light level
from the light sensor. The set point values are a percentage of the full range of
the sensor.
For example: A 500 lux light sensor has a full range from 0 lux to 500 lux. The
value of the set point is equal to the percentage of 500 lux. If the set point is 60%
and the dimming output is enabled then the lux value when the light begins to
dim down is 300 lux [60% of 500 lux] measured at the sensor.
The dimming output will modulate over a 20% range of the sensor so the
dimming output will reach 0% or 0V at 400 lux (80% of 500 lux), the minimum
dimming set-point, see red line in graph below. The relay will open (lights off)
when the light level increases 15% past the minimum dimming set point, see
green line line in graph below. The lights will remain off until the light level
decreases to the minimum dimming set-point where the relay will close (lights
ON) and the dimming output will increase as the natural light decreases.
Control Response with Dimming Output Enabled
If the dimming output is disabled, the set point becomes the light level where
the relay will close and turn the lights ON or the Light-ON-Set point. The Light-
OFF-Set point is 15% greater than the Light- ON-Set point. In this example, the
Light-OFF-Set point = 1.15% x 60 = 69% or 345 lux.
Control Response with Dimming Output Disabled
There are two methods of setting the lighting set points.
1.
Setting the light level set point to an optimum value -
You can adjust
the light level to a comfortable setting and have the controller maintain
this light level. This process is useful in closed loop sensor applications
where the sensor reading is affected by the fixture output (ceiling mount,
near a window, office applications). This set point becomes the maximum
dimming set point when the dimming output is enabled. When the
dimming output is not enabled, the Light-ON-Set point is adjusted 7.5%
