troubleshooting 2-wire controlled irrigation systems introduction to a training series for...

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