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2. Station settings (Plant, Site Info, and Sprinkler dial positions).
This information controls how each station is calculated to water.
Individual stations can have their settings changed to produce the
desired results.
It can take several weeks to dial in a new system for desired perfor-
mance. Make your best effort at the original setup information, but
observe the results. It is common for adjustments to be made in the
start up period.
Enter all settings and track your changes on the ET System Worksheet.
The ET Module has a backlit LCD display, a dial, and 5 buttons. There
is also a recessed Reset button, and a removable lithium
battery cover.
The display is backlit whenever the 24V power (from the SmartPort)
is present.
When power is initially turned on with the dial in the Automatic posi-
tion, the display will momentarily show a welcome screen, and will
then show the Date and Time and the Current ET. Initially, this may
be 0.00 until the sensor has accumulated enough data to generate an
automatic ET (this may take up to one hour).
11:00AM 00SEP05
DAILY ET: 0.10 IN
Setup Overview
Setup is simplified by following the dial clockwise all the way around,
and entering data for each station until setup is complete.
First, select the controller type and station size
(international users,
select Metric measurement first, at the ET Setup dial position)
.
Then, each station will receive its own data for Plant, Soil, and Sprin-
kler types.
Other options related to automatic operation are set, and finally the
dial is returned to the Automatic position (straight up, or 12 o’clock
position). The module will now be ready to run ET-based automatic
irrigation.
The ET Module dial must be left in the Automatic position, or the ET
program will not irrigate! If the ET System is watering, moving the
dial from the Automatic position will cause it to stop.
Global ET % Setting
The ET System uses the modified Penman-Monteith equation to
determine moisture loss from evapo-transpiration. The %of actual ET
used is now adjustable. This allows irrigation to be adjusted based on
a percentage of measured ET, and allows the system to run “wetter” or
“drier” to customize performance for specific landscapes.
ET System is preset to operate with 80% of ET. However, this can be
adjusted (in 1% increments) from 10% to 150%. The higher the %,
the "wetter" the system will run. The adjustment is applied equally to
all stations, which are further modified by their individual settings
(Plant, Site Info, and Sprinkler types). This factor may compensate
for non-ideal mounting conditions, where the sensor cannot be placed
according to ideal specifications.
Hunter recommends observing performance carefully over the first
weeks of operation and adjusting the percentage to tweak system
performance.
Initial Soil Deficit
ET System assumes an initial soil deficit of .1” of water, meaning the
soil is neither saturated nor dry. This relatively neutral value prevents
excessive watering after initial installation.
If soil is very dry when the system is installed, it may be desirable to
run all stations from the host controller first, with Manual Program
starts, for a “normal” watering. Do not over water, but bring the soil to
a naturally moist state before beginning ET operations.
International Users – Metric Setting
ET System is set to Inches-style measurement, but can be quickly set
to Metric. Turn the dial to the ET Setup position, before entering the
other setup screens.
Summary of Contents for ET System
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