According the the EPA as much as fifty percent of the water we use outdoors is wasted through
inefficient irrigation method and systems. One way to easily reduce this water waste
is by adding a soil moisture sensor to an irrigation control. The WaterTec S100 soil
moisture sensor from Baseline can help eliminate unneeded irrigation cycles. It does this by
interrupting the signal between the irrigation controller and the valve if the soil is already
hydrated as a result of a previous irrigation cycle or from recent rain fall. It's also
compatible with just about any irrigation controller. The first thing you need to decide
when adding a soil moisture sensor is where to place it in your landscape. Choose a zone
in your system that requires the most frequent irrigation. Within that zone, place a sensor
in an area that receives average to slightly less than average water from the irrigation
system. A spot midway between two sprinkler heads is usually ideal.
The sensor will eventually be connected to the valve that feeds a selected zone and the
control unit will be installed next to the irrigation controller. Be aware that the distance
from the sensor to the control unit can not exceed 500 feet. This includes the length
of the wires running from the valve to the irrigation controller. Once you've determined
where you will bury the sensor it's a good idea to make a note of the location in case
you need to find it in the future. At this point you can dig a hole for the sensor as
well as a small channel for the communication wires that leads back to the valve. The hole
for the sensor should be deep enough to bury it on it's long edge with the top two to three
inches below the soil surface. The channel for the communication wires should also be
deep enough to avoid any damage from future aeration.
Before you bury the sensor run it's wires back to the valve that feeds the zone where
the sensor is located. Determine which of the valve wires is hot and which is common.
Then slice in the appropriate sensor wire to each connection. The white wire should
be attached to the common connection and the red should be connected to the hot wire that
controls the valve. Secure both sides with standard wire nut until you have completed
testing the unit. Later they will be replaced with waterproof wire connectors. Now, mount
the S100 control unit next to you controller. Be aware that the unit is water resistant
but not waterproof. If your mounting it outdoors make sure it's protected from direct contact
with water. To begin wiring the S100 control unit to your
irrigation controller disconnect the wire currently connected to the common terminal
on the controller. Connect that wire to the white wire coming from the S100 harness. Then
connect the black wire from the S100 to the common terminal on the irrigation controller.
Next, locate the terminal for the valve wire for the sensor zone, disconnect the wire,
and then connect it to the red wire from the S100. To complete the circuit connect the
green wire from the S100 to the same valve terminal. In order to provide power to the
control unit connect the orange wire from the S100 to an available 24V terminal on the
irrigation controller. Touch the end of the orange wire to each of the available terminals
while observing the S100 control unit for an indication light. Attach the orange wire
to the terminal that triggers the light. Finally, if you have irrigation zones that
you do not want to be effected by the sensor you do have the option to bypass two of them.
Connect either the blue or brown wire from the S100 harness to any valve terminal that
you would like to bypass. Be sure not to remove the existing valve wire when you do this.
Once everything is connected you can run a communication test between the controller
and the sensor. To do this press and hold the plus, minus, and read set buttons simultaneously
for three seconds then release. The communication test will take about two minutes as it triggers
the sensor to take one hundred readings. When the test is complete the display will show
the number of errors received. A reading of 000 means there were no errors. If you do
receive an error verify that all of your connections are correct and test again. Refer to the manufacturers
manual for details if you continue to see errors.
After completing a successful test finish the installation by burying the sensor. Make
sure that it is not tilted at an angle. This can lead to incorrect readings due to water
pooling on the surface of the sensor. Also make sure that you have good soil and sensory
contact by packing the soil down tightly around it. Air pockets, rocks, or gravel resting
against the sensor can negatively effect readings. Now bury the communication wires and reconnect
them to the valve using waterproof connectors. Finally, saturate the soil around the sensor
with a garden hose or a bucket of water. This will allow the soil to settle. It will also
provide the hydration required for the calibration process which is covered in a separate video.
If you would like to learn more about the variety of sensors that can help you better
manage the irrigation of your landscape contact your nearest Ewing branch or visit us online
at ewingirrigation.com.