What's the number one reason for customer complaints and
callbacks? If you're like most irrigation contractors, an
improperly programmed controller is the typical answer.
Today's irrigation controllers offer a variety of features
and program options. As much as these modern marvels help
improve the flexibility of an irrigation system, they do increase
its complexity and, sometimes, the frustration you'll experience
servicing it.
The following tips will help give you a basic understanding
of how a controller works, how to program it and what some
of the more complex features might be.
Basic Programming Techniques
The controller energizes the remote control valves that operate
the sprinklers according to the program you set. Basically,
it is an automatic timer which runs a pre-set program that
regulates when and how long a sprinkler should run. The program
dictates which days of the week the sprinklers will run, the
time of day and total run time per zone (or station).
Many controllers can contain more than one program., and
a few models contain independent programs. Each station may
have its own program, which will allow you to enter a different
start times, run times and different days of the week than
the main program.
When a controller is initially set up, you must first program
the current time and the day of the week. All irrigation controllers
need at least three elements to produce a working program:
start time, days of the week to start, and run times for each
station.
Follow three steps to establish a basic irrigation program:
1) Set the start time. The start time is the time at which
you want the controller to begin watering. Once the start
time is set, controllers begin the watering cycle with the
first station; the other stations in the program follow in
sequence.
It's important to note that start times apply to the entire
program, not individual stations. As such, depending on the
controller, you may want to assign several or multiple start
times per station, per day. For example, if you have a new
established lawn, you may wish to water several times a day
to keep the seed or sod moist.
2) Set up the days to run the program. Watering days are
the specific days of the week on which watering occurs (e.g.
every Monday, Wednesday, Friday; or every third day). A watering
schedule is the list of days on which a program runs. Different
controllers allow different schedule options such as a 365-day
calendar, a weekly calendar every other day, every third day,
odd/even days, etc. Again, the watering days apply to the
entire program, not the individual stations.
3) Set the station run times. Station run time is the amount
of time each station will operate. The length of a station's
watering period is called the run time. . Most controller
run times can be set in one-minute increments up to several
hours. For special situations, some controllers can be set
in seconds.
Station run times are set individually for each station and
do not apply to the entire program. So if a station does not
have any time set to run, that station will be skipped and
the next station, in sequence with a run time will operate.
Electromechanical Controllers
The simplest controllers-electromechanical "clocks"-use
gears, dials, and pins to control the irrigation program.
These types of controllers usually have three separate dials
to controls a separate functions: start time, day of the week
to water, and station run times.
To program an electromechanical controller, push the pins
in for "on" or leave them up for "off."
As the dials turn, the pins that have been pushed in press
against the contacts, completing an electrical circuit.
Electromechanical controllers are reliable and easy to use.
However, they offer fewer features than electronic or hybrid
controllers. They are ideal for customers who like to keep
things simple.
Electronic and Hybrid Controllers
Solid-state or electronic controllers are essentially small
computers. They offer more features than the electromechanical
controllers. As such, they are more complex.
Programming a solid-state controller usually requires entering
commands through a keypad. The results of the commands are
visible in a display window; similar to a hand held calculator.
Hybrid controllers combine the ease of use of the electromechanical
controllers with the versatility of the solid-state controllers.
Hybrid controllers have sophisticated electronic circuitry
combined with an easy-to-use panel that feature dials and
switches. A display window guides you through programming,
and displays information about the watering cycle.
Solid-state and hybrid controllers offer multiple programs.
This feature is useful for meeting the watering needs of different
areas of the landscape. For example, a heavily shaded area
requires less frequent watering than a sunny area. By using
a different program for the shady area, you can effectively
water it without under-watering the sunny area. Each program
requires the same three basic elements of an irrigation program.
Master Valve Control
An additional feature to consider when programming a controller
is the "master valve/pump start." Controllers often
have a connection for a master valve or pump start relay.
In some cases, this connection can be associated with each
station. This means that every time the station operates,
the pump start relay or master valve will also operate.
A master valve start is helpful if a station needs extra
water pressure. It allows you to operate a booster pump when
that station is operating. Or, you may have a master valve
that controls the flow of water to the irrigation system.
In this case, you will want to activate the master valve automatically
whenever the program operates.
Note: Make sure the master valve/pump start must be wired
properly to perform this function. See your controller's manual
for instructions.
Shut-down Programs
Most controllers also have a switch to shut down all the
irrigation programs. This is especially useful for turning
off a controller when it is raining or when it has been cloudy
and the soil does not require additional watering.
On more sophisticated controllers, a "rain delay"
feature is available. Rain delay allows you to turn off the
irrigation system for a specific number of days without having
to remember to turn it back on. For example, if the weather
forecast calls for three days of rain, you could stop irrigating
for four or five days. This gives the soil time to dry out
after the rainfall.
Many irrigation systems can have rain sensor installed that
automatically prevents watering when it detects moisture.
The sensor override, or bypass switch, on a controller lets
you turn off the sensor so you can resume irrigation. This
is especially useful when trouble shooting a system. In most
cases, you simply move the sensor override switch to off.
You can then run the station and reactivate the sensor when
you are finished.
Water Budgeting
Most solid-state and hybrid controllers feature a water budget
function. The water budget function allows you to change the
normal station run times without resetting each individual
station.
With water budgeting, one hundred percent is the normally
programmed station run time. You can adjust the run time up
or down (zero to 300 percent) when you want more or less watering
time. This adjustment is done on a percentage basis and is
very effective for adjusting for seasonal weather changes.
If a station that is set to run ten minutes. If you adjust
the water budget to 50 percent, it will then run for only
five minutes. If you adjust the water budget to 150 percent
the station will run for 15 minutes.
Some controllers apply the water budget to all programs and
stations on the controller. Other controllers offer added
flexibility of letting you set a different water budget for
each program. With these controllers, you can adjust the water
budget to zero percent to temporarily turn off a program while
you let the other programs operate normally.
The old adage is true: knowledge is power. Understanding
the three basic elements of irrigation controller programming-start
time, days of the week to start, and run times for each station-will
ultimately cut down on your frustration, and hopefully reduce
customer complaints and call backs.
By: Tom Barrett, Marketing Communications Manager, Rain Bird
Sales, Inc.
