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Oct 2020
Page 33
4.
Rain Voltage Threshold
. You configure this value to determine how sensitive the Sky Master
Pro controller is to rain. This is set at factory to 2.5 volts which means any voltage below this
value indicates a raining condition and will close the contacts of the relay as the default state of
the controller is to use the rain sensor to close relay contacts. If you want to disable the relay
from using rain sensor or cloud input, hit the relay disable button in the GUI which will instruct
the controller to show rain conditions on GUI but not activate any relays. To couple relay with
sensors again, either reboot the controller or hit the Relay Off button. Under dry conditions, the
Rain sensor voltage shows close to 5 volts. When the sensor is wet, the voltage drops close to 0
Volts.
For example, if the sensor was fully wet from rain, it would show a voltage less than 5 volts. For
example, if at least one rain drop falls on the sensor, the high resolution of the spiral sensor
should report close 1 volt or less.
a.
To determine the right threshold value, use a spray bottle to spray a fine mist of water on
the sensor. It’s helpful to turn on “Loop_Read” to get a frequent update of the Rain
Sensor voltage. Notice the Rain sensor voltage after one spray. Repeat spraying the
sensor to approximate the amount of rain you want the Sky Master Pro to consider
“Raining”.
b.
The rain sensor will also consider dew or frost as a threshold trigger for the rain sensor.
This must be considered and potentially recalibrated upon any of these conditions
occurring. Because the rain sensor is not heated, dew or frost can form on the sensor
when the temperature is below the dew point or frost point. To help ensure against false
rain detection, recalibrate the trigger threshold sensitivity above the voltage detected
under these false alarms.
c.
Click “Save Value” to save this to the C:\Sky_Master_Pro_Data\Offsets.txt file. Click
“Upload” to save this to your controller. Note that the Message Box will indicate when
the value is saved to the controller.
d.
Couple Rain and Cloud Sensors
. The rain sensor can also be coupled with rain sensor
and IR cloud activity to trip. If this check box is checked in the GUI under the offset sub
menu, either a rain trip threshold or a Cloudy Condition with activate the relay. Currently,
the coupling of Cloud sensors means a “Cloudy Reported Condition” .
