Transcript H - Controllers and Wire

Irrigation Controllers
The Brains of the Operation
Controllers are effectively the “brains”
of the irrigation system
Used to carry out watering schedules
automatically
Irrigation systems are typically 24
volts
Controllers
Programmed to start watering at
specific stations . . .
At selected times and . . .
And for predetermined durations
(length of times)
Controllers
Large selections available . . .
Fits almost all irrigation needs . . .
And most budgets
Types of Controllers
Digital Controller or Solid State
Hybrid Controller
Electromechanical Controller
Hydraulic Controllers
Digital/Solid State Controllers
Computerized
Digital readout display w/ keyboard
No moving parts
Accurate
Digital/Solid State Controllers
Can be complicated to program
Battery backup – can retain program
for several hours to days depending
upon manufacture
Can be remotely operated
Hybrid Controllers
Combines solid state circuitry with
mechanical type controls
Considered more “user friendly”
Mechanical “user interface” allows for
easier use . . .
Integrated with solid state technology
Hybrid Controllers
Knobs, switches and sliders are the
moving parts
Accurate
Battery backup
Hybrid Controllers
Hybrid Modular Controllers
Electromechanical Controllers
Older
Mechanical technology containing . . .
Motors and gears . . .
Wheels . . .
Dials and pins
Electromechanical Controllers
Considered “user friendly”
Does not loose program in power
outages
Inaccurate – give or take 5+ minutes
Hydraulic Controllers
Connected to valves by small tubing
carrying water under pressure…
When the pressure is released, the
valves open…
When the pressure is reapplied, the
valves close
Hydraulic Controllers
In many cases, the valves are in the
bottom oh the individual heads
Typical in large heads used in sports
turf applications
Controller Placement
Indoor Controllers
Have external transformers . . .
On power cord (wall wart)
Unsuitable for outdoor use
Outdoor Controller Placement
Outdoor Controllers
Cases are water-tight
Internal transformers
Must be "hard wired" using 110v
Outdoor Controller Placement
When used indoors a “pig tail” can be
attached
Outdoor Controller Placement
Correct installation
Inappropriate installation
Outdoor Controller Placement
Should be located within “eye shot” of
the valves they control . . .
Whenever possible
Should never be located within the
spray of the irrigation heads
Controller Features
Versatility is typically a function of
cost with irrigation controllers . . .
More features . . .
More money
Typically, more expensive controllers
have more capabilities
Controller Stations
A station in a controller is tied directly
to one valve circuit or zone . . .
And is numbered 1, 2, 3, etc.
The term “station” can also be
considered as one valve and the heads
connected to it
Programs
A program is a set of watering
instructions or a watering schedule,
including . . .
Days to be watered . . .
Start times . . .
Stop times . . .
Run times or durations
Programs
Controllers with multiple programs
allow increased flexibility . . .
Also allowing multiple start/run times
per station . . .
Program are continuous from start to
finish
Start Times
The number of times a controller can
signal the stations per day . . .
Cheaper controllers have fewer start
times
Start Times
Multiple start times allow for greater
flexibility . . .
Particularly in specialized settings
ex.:
newly planted turf
slope plantings
greenhouses and mist houses
Watering Cycles
A complete set of irrigation
instructions is implemented during a
cycle, including . . .
Start times
Run times
Run days
Watering Cycles
Typical watering cycles are 7 days, 14
days and 15 days
7 day watering cycles limit possible
programs
7 day clocks allow for daily watering
but not every other day or every 3rd
day
Watering Cycles
14 day and 15 day watering cycles allow
greater flexibility for programming
14 day clocks allow for watering every
day or every other day
15 day clocks allow for every day
watering, every 3rd day or every 5th
day
Run Days
Selected days the irrigation program
will operate
Some controllers allow choices of . . .
every day . . .
every other day . . .
every third day or . . .
selected days
Run Days
Many controllers default to an every
day watering cycle in the event of
power / battery failures
Station Run Times
Most controllers have run times from 1
to 120 minutes
Many controllers allow stations to run
in minutes or hours for greater
flexibility
Station Run Times
Specialized controllers have shorter
run times of 1 to 60 seconds . . .
Or for several hours for agricultural
uses . . .
Drip irrigation and . . .
Greenhouse / nursery production
Manual Control Switch
Allows the operator to override the
cycle and manually control the
watering process
Used when testing stations
Also used to manually irrigate after
new planting installations . . .
or any ole time
System On / Off Switches
Allows the entire controller to be
turned off without loosing the
irrigation program . . .
For maintenance reasons or . . .
In the event of rain
Global-Percentage Adjustment
AKA seasonal adjustment switch . . .
Allows the watering run times to be
adjusted up or down . . .
Across all run times in a program . . .
Water budgeting by program from 0 to
300% in 1% increments
Global-Percentage Adjustment
Irrigation programs are developed
based on 100% of the irrigation
requirements
Allows for adjustments up in extremely
hot, dry weather or . . .
Adjusted down as the water
requirements are reduced by cool,
damp weather
Remote Control Systems
Satellite control systems are
programmed at a central computer
Can be tied into any number of
irrigation controllers
Cellular remote systems
Internet connections
Remote Control Systems
Rain Sensors
Tied directly into irrigation controllers
Set to shut off controllers at
predetermined amounts of rainfall
Some older controllers must be
manually restarted
Soil Moisture Sensors
Placed in the soil within the root zone
of plants or turf . . .
Tied directly into the irrigation
controller . . .
Shuts off the controller when soil
achieves predetermined soil moisture
levels
Soil Moisture Sensors
Wiring
Wire
Typically copper
Analogous to the pipe used in irrigation
Smaller wire carries a smaller flow
Smaller wire offers greater resistance
Kinda like friction loss
Wire
As with sprinklers, adequate voltage
must be maintained over the entire
length of the run to properly operate
the furthest valves
Should be covered by 18" of soil
When possible placed under irrigation
service line piping
Loosely snake the wire in the trench
Basic Electrical Terms
Volt (V) – unit of electrical pressure
Analogous to water pressure
Amp (A) – unit of measure for the flow
of electrons
Analogous to water flow
Basic Electrical Terms
Watts (W) – an expression of power
Volts x Amps = Watts
Voltage Transformer – reduces voltage
from 120V to 24V
Analogous to a pressure regulator
Short
Typically caused by a nick in the wire
insulation . . .
Or a loose connection
Allows the electrons to “leak” out . . .
Causes an inadequate voltage supply at
the valves
Control Wire or Hot Wire
Carries current out to the irrigation
valve from the controller
Each valve should be individually
connected to the controller
Can be most any color
Common Wire
Returns current from the irrigation
valve back to the irrigation controller
Common wire can link all valves in series
to the controller
Usually white
Wire Sizing
The wire used to connect irrigation
valves to irrigation controllers is
typically a buriable type referred to
as "underground feed" (UF)
Thermostat wire or door bell wire is
NOT acceptable for direct burial
Wire Sizing
Determine the length of the run – valve
to clock
Determine static water pressure
Greater static pressure requires larger
wire to overcome higher water
pressure resistance when opening the
solenoid
Wire Sizing
Use a wire sizing chart for the
appropriate static pressure to
determine the appropriate wire size
For most residential applications, 14
gauge wire is adequate
Expansion Coils
Expansion coils are coils formed in the
wire at the irrigation valves
They allow the wires to expand and
contract without pulling apart at the
connections
Expansion Coils
Expansion coils allow the valve to be
serviced without having to cut
controller wires to gain access
8 or 9 wraps around 1/2” pipe
Dry Splice Connectors
Used to connect two to several wires in
underground vaults . . .
And at valve connections . . .
Reduce or eliminates corrosion at
connections . . .
Reduces chances of faulty connections
occurring