Transcript Irrigation Troubleshooting

Irrigation
Troubleshooting:
What does it take to be an
“Irrigation Troubleshooter”?
•An Electrician
•A Plumber
•An Electronics Technician
•An Irrigation Technician
•A Laborer
•ALL OF THE ABOVE
The 7 components of an
irrigation system that we need
to be concerned with:
• Water Supply
• Backflow Preventer
• Main Line
• Electric Valves
• Lateral Lines
• Heads
• Controller
When a customer comes in or
calls with an irrigation problem,
what do you do?
Ask Questions
• What is malfunctioning?
– Is it the controller, valves, heads, sensors, etc.?
• Has anyone been working in the area other than
you?
• Have there been any storms lately?
• Can you manually turn on the system?
• Has the pressure been reduced in the area?
• Etc.
There are two main divisions of
an irrigation system. This will be
the first question of your
Troubleshooting Plan.
Is the problem
Electrical
or
Hydraulic?
Electrical Troubleshooting
Two-wire technology for large systems
Traditional systems require at least one wire per valve, plus
common ground wires.
Two Wire
Direct Burial Connectors
DBY/DBR30v Max
DBY/DBR -6
600v Max
DBR/Y 600v
Max
Cut us some slack…
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5 feet slack wire, per
splice
– At decoders, and at T
splices
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Always in a valve box
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Stake decoder upside
down (recommended)
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Up to 150 feet from
decoder to solenoid
(shorter is better)
Electrical Terminology
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Alternating current (AC) – Standard household current. Most irrigation
systems use AC current.
Amperage (AMPS) – Quantitative measurement of flow of electricity,
similar to Gallons per Minute in irrigation.
Circuit – In irrigation terms, the electrical wiring path from the station output
terminal to and through the solenoid back to the common terminal.
Connection – Connection of one wire with one or more wires inside of an
approved wire nut or other connecting device.
Direct Current (DC) – Directional flowing electricity: i.e. current flowing
from the positive terminal of a battery through a device and back to the
negative terminal.
Field Wiring – the wiring between the controller and any device/valve
installed in-ground.
Ground – In electricity, it is always earth ground
Multimeter (Volt OHM-Meter) – Digital or analog testing device for
measuring electricity’s characteristics (voltage, amperage, resistance).
Electrical Terminology
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OHMS/Resistance – The resistance encountered by electricity in wiring or
devices on a circuit, similar to friction loss in irrigation terms.
Open Circuit – Term given to a circuit when the pathway for electricity has
been severed or is not completed.
Primary Side – The side of the transformer that is connected to the 120vac
supply.
Secondary Side – In the irrigation industry, it is the 24vac output side of the
transformer.
Short Circuit – Term given to a circuit where electricity bypasses the
intended and goes directly from the hot to the common wire.
Short To Ground – the electricity has a direct path from the wire through
the insulation to ground.
Solenoid – an electrical device on valves that when electrified creates a
magnetic field that pulls a metallic plunger.
Electrical Terminology
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Terminal Strips – A collection of terminals numbered to differentiate zones.
Terminals – The connecting device on the panel of the controller that the
field wires are attached into. There are station output terminals and
common terminals.
Voltage (VOLTS) – Quantitative measurement of the power of electricity,
similar to water pressure (PSI).
Zone – Irrigation term used to differentiate one circuit from another: i.e.
zone 5 or zone 12.
Zone Wire VS. Common Wire – The zone wire is the wire connecting a
station output terminal on a controller to a solenoid or device. The common
wire is the wire connecting the solenoid or device to the common terminal.
Digital Multimeter (Volt-ohm
meter)
Using The Multimeter
• Know what you are measuring
– Volts……AC or DC voltage?
– Amps
– Ohms
• Set the meter to the proper scale
• BE SAFE! Call a certified electrician if you
watch “Home Improvement” regularly
Voltage
• Controller power specifications
– 120 VAC ± 10% (108-132 VAC)
• Does my controller require a dedicated breaker?
• If a high amperage device like an irrigation pump
is powered on the same branch circuit as the
controller, the answer might be--YES.
• Why? The high amperage demand of the pump
causes a severe drop in voltage.
Measure Transformer Voltage
Current
• Must be measured in-circuit
• 120 VAC supply
– Controllers use approximately 0.25 amps
– Add 0.12 amps for each solenoid
• Refer to the manufacturer’s specifications
Resistance
Most useful of all measurements in the field
• Used to test for bad:
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Solenoids
Field wiring
Transformers
Shorts to ground
Resistance
DO NOT MEASURE
RESISTANCE WHILE THE
POWER IS ON!!
Resistance Terms
• Open Circuit
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Think of an “open” drawbridge
Turning off the light switch at home = open
Indicates no connection
Station will not work
• Short Circuit
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The common wire is touching a station wire
Internal solenoid wires touch-- too soon
Result? The fuse or circuit breaker opens, or……
The diagnostic circuit breaker “skips” the station
Electrical Troubleshooting
Summary
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Check the outlet that the
controller is plugged into.
Make sure it has 120 volts
and that the outlet is not
connected to a switch or is
not part of a ground fault
circuit.
Is the controller putting out
24 volts? Test the terminal
strip with a multimeter to
determine output voltage.
Is there continuity through
the solenoid?
Electrical Troubleshooting
Summary
4. If not, then test the ohms on that station. A high
reading (over 60 ohms) indicates an open
circuit.
5. If the circuit is open, is the problem a solenoid
or a cut wire? Go to that valve box, disconnect
the solenoid from the valve wires. Take the
ohm reading of the solenoid. If this reading is
high, then replace the solenoid.
6. If the solenoid is normal, then we have a wiring
issue. Here we will turn to specialized
equipment for tracking wire.
Common Valve Problems
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Check resistance on the
solenoid.
Check to be sure the
flow control is not all the
way closed.
Check for trash inside
the valve.
Check to make sure
bleed tube is not
clogged.
Solenoid Resistance
• Acceptable range: 20 - 60 ohms
– More than 60 ohms is considered open
– Less than 20 ohms is considered shorted
Solenoid Ohm Resistance Values
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Asco (Bermad/ClaVal)
Champion
Greenlawn
Griswold
Hardie/Irritrol
Hunter
Imperial ATTV
Nelson
Orbit
RainBird A series coil
RainBird B series coil
RainBird DV series
Superior
Toro 1”
Toro ¾”
Weathermatic
14.4 ohms
21.7 ohms
22.7 ohms
21.1 ohms
24.6 ohms
29.7 ohms
21.7 ohms
22.2 ohms
20.2 ohms
28.5 ohms
23.8 ohms
51.8 ohms
23.1 ohms
+/- 28 ohms
+/- 23 ohms
34.1 ohms
Electronic Tracking Equipment
1. Progressive Electronics 521
2. 508
3. Pulse toner
4. Station master
5. 2003 Fault Finder
Hydraulic Troubleshooting
Hydraulic Troubleshooting
• Pressure - 2 Kinds:
– Static (Hydrostatic)
– Dynamic (Hydrodynamic)
• Check using a pressure
gauge on the backflow,
hosebib, and heads.
Hydraulic Troubleshooting
• TIP – always begin at the
beginning.
1. Start at the beginning of the water system. Make
sure all irrigation water valves are open.
Hydraulic Troubleshooting
2. Is the backflow working
properly?
• Dual Check – you can’t
tell by looking at it.
• PVB – check the bonnet
and poppet assembly
for cracks or warpage.
Also check the o-ring.
• RPZ – look in both
check valves for trash or
cracks.
Check the o-rings.
Check the overflow valve.
Hydraulic Troubleshooting
3. Is the mainline holding water pressure? A pressure
gauge comes in handy here.
4. Are the electric valves opening and closing properly?
Obstructions around the diaphragm can cause
problems. Check the flow control valve for proper
opening position. Is it installed backwards?
5. Does the lateral pipe have any breaks or kinks in it?
Could be trash from a previous (BAD) repair, tree roots,
etc.
Hydraulic Troubleshooting
6. If there is no break in the pipe, the valves are operating
properly, or there are no problems with the backflow
preventer, and a sprinkler head is still not working
properly; what would you do? Check the screen and/or
nozzle in the sprinkler head first for clogging.
7. Sometimes rocks and debris can get stuck in the spiral
elbow or the swing pipe gets kinked. You must dig up
the head to get at these headaches.
8. Finally, when all is checked including last head
pressure, the only answer may be in the design itself.
Make sure that the zone requirements do not exceed
the water source.
Tools Needed to
Troubleshoot
•A multimeter
•A 4in1 screwdriver
•12” channelock pliers
•A pressure gauge
Irrigation Troubleshooting
Any Questions?