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TROUBLESHOOTING 2-WIRE CONTROLLED IRRIGATION
SYSTEMS
INTRODUCTION TO
A Training Series for ProfessionalsCopyright © 2014 Armada Technologies LLC
Who is Armada Technologies?
• Founded in 2004• Based on 40 years in the Test Industry• NOT irrigation professionals! (That means you
know more than I do about water and light)• We do know LOTS about Testers.
OBJECTIVES
• Terminology• Irrigation System Types• Troubleshooting Goals• Tools Available• How to Use the Tools
Electrical Meters Solenoid Activator Wire & Valve Locators Ground Fault Finder Wire Radar
What We Can Use …
These electrical tools are time-savers. They can turn a day of chasing and
digging into an hour of work.
Electrical Testing Can Help Answer Common Questions and Requests.
Why is the whole system dead?
Is the controller the problem?
Are there faults in the buried wire?
The controller shows over-current. What is wrong?
Where are the wires buried?
How do we track down problems across a large area?
WATER AND LIGHTINGSYSTEM TEST& MEASUREMENT
LOCATING BURIEDWIRING AND VALVES
TROUBLESHOOTING BURIED WIRING
PRODUCTS COMMONLY USED
Pro300
Pro800
GFL3000
Pro400
Pro93
Pro48
Pro30
Price
General Use Advanced Features
Pro30
Pro93
Pro91
General Purpose Multimeter
Hi Sensitivity and True RMS readingFor 2-wire irrigation and LED lighting
METER SELECTION GUIDE
True RMS reading for LED lighting, easy to use
Easy-to-use, Multi-purpose, clampmeter and multimeter
Pro90
TYPICAL USES FOR A METER
Pro30 QUICKerCheck Clock Output: 24-36 VSelect 200Check Solenoid Resistance:
10-100 ohmsSelect Ω 2 Check AC Power: 110-220 VSelect 500
V
V
V
Check Batteries: 1.5-12 VSelect 20
Armada Technologies
CONDITION? RESISTANCE READING
Short circuit 1 – 10 ohms
Open circuit “OL” – Too big to read
Partial Open (Bad Splice) 70 – 150 ohms
Normal solenoid 20 – 60 ohms
VOLTAGE READING
Normal Clock Output 24 – 36 volts
TYPICAL USES FOR A METER: Checking an Irrigation Controller Zone
with the Test Probes
Check electrical currents one wire at a time.
Clampmeters can measure electrical current by just closing the spring-loaded
jaws over a wire.
This is especially useful in testing lighting systems and 2-
wire irrigation systems.
Pro93 ‘Leakage’ MeterCan read AC currents of
less than 1 mA (milliampere)
IRRIGATION SYSTEM TYPES
• Multi-wire (Wire-per-valve plus common)
• Two-wire (Single control+power)
Multi-wire Controller
Valve Solenoid
Clocks or controllers fire valve solenoids that release water into sections of pipe feeding watering zones.
Direct Buried Wires, One per Valve
COMMONCOMMON
Valve Solenoid
Valve Solenoid
Watering Zone Watering Zone Watering Zone
MULTI-WIRE
2-wire Controller
ValveSolenoid
DecoderDual Decoder Decoder
Many newer, long distance, many-valve system designs often use a smart controller, 2-wire data link cable and ‘decoders’ to fire valves.
ValveSolenoids
ValveSolenoid
Two-conductor 12 - 14 Gauge Direct Bury Cable
TWO-WIRE
DIFFERENCES BETWEEN ELECTRICAL IRRIGATION SYSTEMS
• Multi-wire Wire-per-valve plus a common wire.24 Vac powering, On/Off control.Valves can be found with a locator.Simple waterproof splices can be used.Cable runs can be 10 feet to 2,000 feet.Cable depth 12 – 18 inches
• Two-wire • Single cable for control+power.• Cable runs can be many 1000s of feet.• Smart controller can help with troubleshooting.• Valves can’t be found with a locator.• Cable depth 24 - 36 inches.
Diagrams from Tucor
Buried Wiring for Conventional Multi-wire vs. Two-Wire Systems
‘STAR’ or ‘HOME RUN’
‘DAISY-CHAIN’
Some Two-wire System Vendors
Rainbird
Hunter
Tucor
Baseline
Toro
Weathermatic
CentralSystem
2-wire FieldSystem
001 002
003 004
005 006007
In a 2-wire system a single cable can control many valves.
Valve Boxes
Decoder and ValveSolenoid
TESTING THE FIELD SYSTEM.
TROUBLESHOOTING
1. Controller 2. Field Wire 3. Decoders 4. Valve Solenoids
As with any type of irrigation control system,start from the source of power and work outward
Contoller F ield W ire Solenoid valve
D iagnose system
Short
Broken wire
Bad splice
USING ELECTRONIC TESTERS TO ELIMINATE SUSPECTS
Start by eliminating the controller or water supply as the source of the
problem.
A Single Two-wire Cable ChainsZone Valves Together for
Power and Control
Courtesy Hunter Industries
FIND THE WIREPATH
CHECKING DECODERCONNECTIONS
FIND THE WIRE DAMAGE
Pro800DLocator
Pro93True RMS Clampmeter
GFL3000Ground Fault
LocatorGood RangeDirect & Antenna Connect
High SensitivityTrue Power Reading
Type Recommended by Sys MfgrsNot Carried by Other Suppliers
Fast, Precise Damage Location
Pro400TDR Wire
Radar
Measure cable lengthFind distance to splicesSpot opens and shorts
Price
General Use Advanced Features
Pro30
Pro93
Pro91
General Purpose Multimeter
Hi Sensitivity and True RMS readingFor 2-wire irrigation and LED lighting
METER SELECTION GUIDE
True RMS reading for LED lighting, easy to use
Easy-to-use, Multi-purpose, clampmeter and multimeter
Pro90
Controller Powered On
Volts to Field Cable OK?
Troubleshoot Clock AC power, fuse
N
Y
Test Currents/ Leakage at the Control Cable
Disconnect the Field
Cable
Excess Main
Current?
Y
N
Troubleshoot Specific
Zone Faults
Check for Break or Open Splice
Check valve solenoid
resistance
Zones apparently not working: Basic Troubleshooting
Operate valves with
bleed
Locate cable path
Excess Current in One Leg?
Low Main
Current?
Check for Pair Short or Bad
Decoder
Check for Cable Damage or Wet
Splice
NY Y
N
Inspect path or use A-
Frame
Locate cable path
We Are Hunting for WiringProblems Most of the Time
Courtesy Hunter Industries
Bad Splice: Corrosion, exposed metal, damage
Cable Damage: Cuts, skinned insulation, crushed or stretched wires.
Bad Decoder: Lightning blown open or welded short.
Courtesy Hunter Industries
Valve Box
Decoder
Valve
Ground Plate
CentralSystem
FieldSystem
001 002
003 004
005 006007
2-Wire Control Links are Chains of Smart Valve Solenoids Wired in Series, Each Identified by an ID Number
A bad splice or single wire break can take down whole groups of watering zones.
IRRIGATION SYSTEM
DIAGRAM & NOTES
TEST EQUIPMENT FORGREEN PROFESSIONALS
DATE: 27 May 2014
LOCATION: Fountain Hills, AZ
PROBLEM: Usability of existing buried trunk cables.
NOTES:
Tucor FlowmasterTWC100
TRUNK 2, typical 6 mATRUNK 1, typical 25 mA
No Alarms, Manual button flashingBoth Trunks at 31.5 Vacrms
IRRIGATION SYSTEM
DIAGRAM & NOTES
TEST EQUIPMENT FORGREEN PROFESSIONALS
DATE:
LOCATION:
PROBLEM:
NOTES:
Do yourself a favor -- take notes and make a sketch of what you find.
Map the cable routes.
Identify zones and decoders from records.
Note any measurements made like cable resistance.
Note previous mods or repairs.
WIRE TRACKING AND VALVE FINDING.
2-wire Controller
Valve
Decoder
Valve
Decoder
Valve
Decoder
Pro800 Hi-Power Locator
To Begin With, You Need to Know the Route of the Buried Cable and
Locations of Valves
Locating Buried Cables and Pipes is Part Science, Part Art.
Modern electronics have made it simpler and less expensive.
$200
$1,000
ContractorPrice
Compact Full Feature
Pro290
Pro300
Pro871/C
Pro700
Pro800/D
Lighting
Wire & Valve
Wire & Valve
Hi Power Wire & Valve
Utility
Receiver
Antenna
Transmitter
Head of Traced Cable
Ground Stake
The Parts of the Locating Process.
PEAK SENSE
NULL SENSE
Locator Features and Uses
o Transmitter Power (range & depth)o Transmitter Frequency (range)o Signal Connection – Direct or Magnetic
(cable access)o Receiver Antenna – Peak or Null
(spot location)o Depth Measurement (spot location)
Transmitter
Radiodetection
Magnetic Field
The Ideal Locating Arrangement.
Target ‘Zone’ Wire
Both Zone Wires Disconnected At the Controller
Zone Valve
Ground StakeLocator Transmitter
Establish a Current Loop
Zone 1 Zone 2
LOCATOR
Valve
Decoder
Valve
Locators find valves (and valve boxes)by creating large signals at the solenoid.
In 2-wire systems the decodersblock that signal.
Locators put their ‘tag’ signals on by directly connecting to the wires, clamping a transformer jaw around a cable or by broadcasting a field into the ground.
Broadcast MethodClamp Method
Direct connection to the wire or cable is the best.
Radiodetection
Locators put their ‘tag’ signals on by directly connecting to the wires, or they can use induction - clamping a transformer jaw around a cable or by broadcasting a signal into the ground.
Inductive Broadcast Method
Direct connection a wire is best, but there are other ways.
Locator’s Internal Antenna
Pro800D
The broadcast antenna coil is located in the bottom of
the case, under the headset and lead storage spot.
The broadcast signal saturates an area for at least 15 feet around the
transmitter – it is only possible to trace cables
beyond that area.
Cable Locating Tips
• Size up the situation, look around for signs that will give you clues about cable routes.
• Make a sketch of the area and notes on the equipment you see.
• Look for locating marks like flags or paint, and be prepared to make your own marks.
• Whatever you are told about what is in the ground and where it goes, be skeptical.
• Remember as you start to locate that success is 50% science and 50% art (experience).
TESTING THE FIELD SYSTEM.
Controller Controller On - Built-in Diagnostics checkField wire powered – 30 to 36 volts, or 24 Vac test power unit
Field Wire First disconnect and check resistance
Each wire to ground greater than 500 kilohmAcross wire pair greater than 100 kilohm
With controller on or in troubleshooting modecheck total powered loop current in each of the 2 wires
Decoders
Locate cable pathLocate valve boxesSpot check power current passing through the box and going
to the local decoder.
Valve Solenoids With water on do a manual bleedResistance check solenoid 20 – 80 ohmsUse Pro48 tester for solenoid operation check.
The General Process
2-wire Controller
Valve
Decoder
Valve
Decoder
Valve
Decoder
Pro93 True RMS Clamp Meter
Toro
The Key to Finding Open Circuits or Shorts is a Sensitive AC Clamp-meter
2-wire Controller
(puts out about 35 V)
Valve
Decoder
Valve
Decoder
Valve
Decoder
You Have to Power the Field Cable to Use a ClampmeterTest Power Unit
(puts out about 24 Vac)or
Valve
Decoder
Valve
Decoder
Valve
Decoder
You Can Use the Power Unit and Clampmeter to Check for Faults
Test Power Unit(puts out about 24 Vac)
The current between either wire and ground should be less than 50 mA
With the test power connected to the wires the clampmeter around both wires should show zero current.
Controller Powered On
Volts to Field Cable OK?
Troubleshoot Clock AC power, fuse
N
Y
Test Currents/ Leakage at the Control Cable
Disconnect the Field
Cable
Excess Main
Current?
Y
N
Troubleshoot Specific
Zone Faults
Check for Break or Open Splice
Check valve solenoid
resistance
Zone apparently not working: Basic Troubleshooting
Operate valves with
bleed
Locate cable path
Excess Current in One Leg?
Low Main
Current?
Check for Pair Short or Bad
Decoder
Check for Cable Damage or Wet
Splice
NY Y
N
Inspect path or use A-
Frame
Locate cable path
Near the Controller, Currents Should Be the Sum of the Decoder Currents
1 to 10 mA each
AB
D
Pro93 Clamp-meter Measuring Points in a Valve Box
C
Checking electrical power flow and cable continuity means measuring
electrical currents.
A: Valve resistanceB: Main power InC: Decoder powerD: Main power Out
When a Zone is Activated, Total Current Should Be the Sum of
the Decoder Currents Plus one Solenoid (about 200 mA)
FINDING NICKS AND CUTS IN BURIED WIRES.
The GFL3000 A-Frame isolates breaks in buried cable insulation.
Finding a Break or a Nick in the Insulation.
Radiodetection
Once you know the path of the target cable, you can use the tracking pulses from the GFL3000 to find the damaged spot.
Moving across the wire path to center the needle will bring you to within a shovel width of
the damage.
CHECK DISTANCES & FIND WIRE DAMAGE
Pro400TDR “Wire
Radar”
• Measure cable length• Find distance to splices• Spot opens and shorts
Example display: A valve solenoid 100 feet down the cable with a splice at 75 feet.
The Pro400“Wire Radar”
Examples
The key information appears in this area.
Once the cable correction factor ‘Vp’ is set, you can read distances down the cable by
moving the cursor
Short circuit 50 feet down the cable.
Cable open at 100 feet,
splice visible at 75 feet.
Demo Videos are on DVD and can Be Seen at www.armadatech.com
Armada Technologies on the Internet of Things
Main web site training videoshttp://armadatech.com/training-videos
The Armada YouTube Channel for Videoshttps://www.youtube.com/user/ArmadaTech
Armada on Facebookhttps://www.facebook.com/ArmadaTech
Armada blog with downloadable application noteshttp://armadaupdate.wordpress.com/
Questions.
2-wire Data+Power
Water Supply
Decoder
Valve Solenoid
Super Splices
Watering Zone
TYPICAL 2-WIRE VALVE BOX
Splices are the weakest link in the field system.
Hunter