{"id":4167,"date":"2019-01-08T06:00:46","date_gmt":"2019-01-08T11:00:46","guid":{"rendered":"https:\/\/innovativepixel.com\/IGIN\/?post_type=features&p=4167"},"modified":"2021-12-29T15:45:43","modified_gmt":"2021-12-29T20:45:43","slug":"detectives-of-irrigation","status":"publish","type":"features","link":"https:\/\/innovativepixel.com\/IGIN\/features\/detectives-of-irrigation\/","title":{"rendered":"Detectives of irrigation"},"content":{"rendered":"

When I was in high school, I read all the Sherlock Holmes stories I could get my hands on. It was fascinating how the great detective eliminated first one possibility, then the next, and the next, until he figured out exactly what happened and \u201cwhodunit.\u201d How, from a cigar ash, Holmes could deduce what type of cigar produced it, where it was bought, and even some of the smoker\u2019s personality traits.<\/p>\n

It may never become the source material for a major motion picture, but an irrigation troubleshooter is also a detective. He looks at the clues he\u2019s seeing at the \u201ccrime scene,\u201d and, calling on his experience and knowledge, pieces together the puzzle. He checks out one probable cause, rules it out, then moves on to the next possibility.<\/p>\n

Simple and logical. If only that were true. But there are \u201cwild cards\u201d out there in the field that can throw you for a loop. As Holmes once said, \u201cOnce you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.\u201d<\/p>\n

In general, with irrigation systems, the truth will fall into one of three main categories: mechanical, electrical or hydraulic.<\/p>\n

For Tim Black, CIC, CID, CLIA, CIT, owner of Irrigation Tech<\/a>, Rochester, New York, the investigation begins with skepticism about the first eyewitness account. \u201cEvery time I show up to a troubleshooting call, I know that what the person tells me the problem is, isn\u2019t really the problem,\u201d he says. \u201cFor instance, a person will say, \u2018I have a leaking head\u2019 but there\u2019s really no such thing; what they really have is a leaking valve.\u201d<\/p>\n

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\u201cEvery time I\u00a0<\/span>show up to a\u00a0troubleshooting call, I know\u00a0that what the\u00a0person tells me the problem is,\u00a0isn\u2019t really the\u00a0problem.\u201d\u00a0\u2013 Tim Black, Irrigation Tech<\/p><\/blockquote>\n

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In fact, this sort of thing happens so often that it\u2019s become an inside joke. \u201cThat\u2019s one of those things we laugh about \u2014 what we refer to as a \u2018Mr. or Ms. Homeowner\u2019 call. What they mean is that it\u2019s slow-leaking, and the only way for that to happen is if water is dribbling by the control valve,\u201d says Black. \u201cThat is always a mechanical problem.\u201d<\/p>\n

But these investigations can be so complex that even experts will disagree. Craig Otto, CIC, CID, CIT, CLIA, CLWM, owner of Irrigation Otto<\/a>, Big Lake, Minnesota, and a technical trainer for the Rain Bird Academy, says \u201cI\u2019m not sure that I would agree 100 percent that a leaky head is really a valve problem. Sometimes sprinklers will lose a nozzle. Another thing that\u2019s fairly common with rotors is you can get a weepy seal, especially if they\u2019re older rotors.\u201d<\/p>\n

\u201cAnytime we do a troubleshooting class, we emphasize that there\u2019s a strategy to this,\u201d says Chris Pine, CID, CIC, CLWM, CLIA, CIT, MCLP, CLVLT and president of BluGreen Solutions<\/a> and a partner in IrriTech Training, Pocasset, Massachusetts.<\/p>\n

\u201cYou isolate exactly where the problem is through a process of elimination. It\u2019s the same process, whether it\u2019s a traditional irrigation system or a two-wire.\u201d<\/p>\n

Pine says he\u2019s one of the people who gets called when a contractor is completely stumped. \u201cA guy called me a couple weeks ago saying, \u2018I\u2019ve been in this business for 25 years, but I just can\u2019t figure this out.\u2019 I took him through the process and it turned out that the problem was in the controller. Almost every time, if you narrow it down using this process, you\u2019ll find the source of the malfunction.\u201d<\/p>\n

You start with the easiest thing to eliminate first, says Black. \u201cLet\u2019s say you have a zone or multiple zones that will not activate. That could be the controller, the wire path, a valve or more than one valve.\u201d<\/p>\n

Once you determine that it\u2019s zone A that has the problem, you next need to find the valve and activate it to verify that it does, indeed, belong to zone A. Once you think you\u2019ve isolated exactly what\u2019s causing the problem, you confirm it with a test so you don\u2019t end up fixing something that isn\u2019t broken.<\/p>\n

\"troubleshoot
A 1 1\/2-inch valve and pipe. The pipe was broken as a result of a piece of large equipment having placed its outrigger on the valve box. While broken pipes are a common source of problems with irrigation systems, it isn\u2019t always easy to determine that; it can still take some detective work. (Photo: Tim Black, Irrigation Tech)<\/figcaption><\/figure>\n

The ohmmeter tells (almost) all<\/h2>\n

When David Clarke, CIT, CIC, CLIA, CLWM, a commercial irrigation service tech at JB Lawn Sprinklers Inc.<\/a>, Wilmington, North Carolina, goes on a call, he makes sure his ohmmeter goes with him.<\/p>\n

\u201cThe first time I visit a site with a traditional, non-two-wire system, before turning anything on, I go right to the controller, take ohm readings and write them down. Very quickly, it\u2019ll give me little clues before I start trying to run the system and end up driving laps around the neighborhood chasing after ghosts.\u201d<\/p>\n

The ohmmeter readings can tell him, among other things, that there might be two valves that have been wired together. That could explain a pressure problem before he even starts counting the number of heads or figuring out the gallonage. Maybe a wire became disconnected or damaged in a place where nobody could find it so someone just jumped that valve\u2019s connection over to the next one.<\/p>\n

\u201cOften, valves end up wired together for just that reason,\u201d says Clarke. \u201cWe\u2019ve seen a lot of two-valve combinations that were done in an attempt to keep a pump from short cycling. That almost never works.\u201d<\/p>\n

Pine says the simplest way to determine if a problem is electrical is to remove the electricity. If the problem stops or doesn\u2019t exist at the point, you can assume that it\u2019s an electrical problem and begin isolating it.<\/p>\n

Let\u2019s look at a common problem, a zone that\u2019s not coming on. Following the method of starting with the easiest thing, Black first finds the number of that zone on the controller, activates it and checks the voltage. \u201c60 seconds later, I\u2019ll know if the controller is the source of the problem or not.\u201d<\/p>\n

\u201cNow, let\u2019s say the controller is working properly,\u201d says Black. \u201cThe next thing I\u2019m going to test is the wire path. I\u2019m going to turn the controller back off, and then I\u2019m going to get my ohmmeter and take a resistance reading from that point, at the controller, out to the field. A proper resistance reading will be between 30 and 60 ohms. It can be slightly below that or slightly above, but it needs to be darned close to that.\u201d<\/p>\n

\u201cIf it\u2019s good, then I know I\u2019m going to have to find the valve, and that may mean I\u2019ve got to break out my tracking equipment because usually I don\u2019t know where it is. I may have to spend a good chunk of time tracking down that valve.\u201d<\/p>\n

If, on the other hand, he\u2019d gotten a resistance reading that was too high or too low that would give him a clue as to where he should start looking next. An ohmmeter reading of infinity could mean that the solenoid on the valve is totally shot, maybe from a lightning strike, or that the wires out to that zone or zones were cut by a shovel. He\u2019d get the same result from both, but in either case, he\u2019s at least narrowed down what the problem is likely to be.<\/p>\n

Black says if you know where the valve is, you can eliminate one possibility fast. \u201cYou go to the valve, turn on the voltage again and pull the wires off the solenoid. See if it\u2019s getting voltage and read what the resistance is through that solenoid. If it still doesn\u2019t work, now you\u2019ve narrowed it down to the wire path, somewhere between the valve and the controller.\u201d Then, you may have to pull out some of what Black calls \u201cthe cool toys we have in our industry,\u201d a wire tracker and a fault finder. If a wire path is leaking voltage to ground, these tools will tell you exactly where it is.<\/p>\n

If a zone keeps running and running and won\u2019t shut off, it could be that a valve is stuck in the on position, according to Black. That can be either electrical or mechanical, so once again you start with the easiest thing and test that the controller is sending voltage to that valve.<\/p>\n

\u201cA voltage spike or lighting hit can scramble a controller,\u201d Black says. \u201cI\u2019ve come across some that have been zapped, and they were sending voltage out to all the zones. That\u2019s a problem. In that case, turn all the power off to the controller, including the backup battery, then power it back up again and it\u2019ll probably be fine.\u201d<\/p>\n

If you\u2019re pretty sure it\u2019s a valve problem, start by analyzing the symptoms, Black says \u2014 not opening, not closing or leaking \u2014 to figure out what\u2019s going on inside the valve. It\u2019ll often be some type of a problem with the diaphragm not opening or closing.
\nA valve could be stuck on because a bit of debris got wedged under the diaphragm. \u201cYou can make the diaphragm lift higher than it normally does by turning the solenoid open or by using the bleeder screw,\u201d says Black. \u201cBy doing that and then closing it again, it\u2019ll wash out whatever the object was. If you get away with that, you\u2019ve just saved yourself gobs of labor.\u201d<\/p>\n

\u201cUsually that problem has something to do with the water on top of the diaphragm, what we call the pressure chamber,\u201d says Black. \u201cBut let\u2019s say that\u2019s not the problem \u2014 then you probably have a mechanical problem at the valve, which means now you\u2019ve got to find the valve, turn off the water, open the valve and see if something\u2019s stuck in it that you can just remove. But if it\u2019s damaged the valve, you\u2019ll have to replace all or part of it.\u201d<\/p>\n

The goal here is to be able to repair the valve without having to replace it. If you can analyze the symptoms, you can often avoid that outcome.<\/p>\n

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TECH TIP:\u00a0Check the controller with an ohmmeter before you do anything else and write down the readings. They will give you clues that can save you lots of time.<\/p><\/blockquote>\n

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Hydraulics or do the math<\/h2>\n

If the problem isn\u2019t electrical or mechanical, it\u2019s hydraulic. \u201cA hydraulic problem, such as a real leak, has to be ruled out first,\u201d says Clarke. \u201cIf you verify that you don\u2019t have a leak, then you have to figure out how many heads and how many gallons per minute the zone is trying to use and compare that to what size pipe it\u2019s built out of and how far away from the source it is.\u201d<\/p>\n

What you\u2019re looking for, according to Clarke, is a design flaw, or some change that might\u2019ve occurred after installation that made the zone not function properly anymore \u2014 things like adding too many heads to a zone or using oversized nozzles during a repair. This is very common especially on properties that have had many different irrigation caretakers over the years.<\/p>\n

He says, \u201cYou have to learn the limits of the way that it\u2019s piped and see if you can get it back to full pressure functionality before trying to analyze coverage or before you think about adding heads, adding a valve, or whether you need to add a \u2018hold zone\u2019 or split a zone in half. That\u2019s a challenge without a map because once you get past the valves, you can\u2019t use a wire tracker. You have no idea where that pipe is, other than the fact that it\u2019s connected to those heads.\u201d<\/p>\n

\"troubleshoot
An irrigation professional on a troubleshooting call sometimes has to, quite literally, dig for clues to find the source of a problem. (Photo: Rain Bird)<\/figcaption><\/figure>\n

Hydraulic problems can also be caused by too much flow through a pipe resulting in too much volume. Or too little flow because of some restriction of the pipe.<\/p>\n

Black will sometimes put his ear to the ground, like someone in a western film, to hear restricted flow. \u201cI\u2019ll listen somewhere between the heads that work and the heads that don\u2019t. You can hear where the flow is being restricted; it can be quite loud.\u201d<\/p>\n

\u201cWhat I\u2019ll often find is a big, nasty wad of roots. They\u2019ll get so fat that there\u2019s no void space between them and they\u2019re like a solid mass of wood, crushing the pipe. All our service trucks have a battery-powered reciprocating saw and lots of long blades. You just stab them into the ground and start cutting.\u201d<\/p>\n

Once you\u2019ve learned the system, you can stop asking the client questions and start telling him what his options are, Clarke says. \u201cThe beauty of hydraulics is that two plus two always equals four. If you can\u2019t add any more heads to the zone, and you\u2019re confident in your math, then you can simply tell people that.\u201d<\/p>\n

\u201cOne of the best ways to determine that is by measuring pressure differences in the system, but not a lot of contractors do it,\u201d says Pine. \u201cYou need to have either a tool that measures pressure at the sprinkler or at another connection to the pipe to determine how much pressure loss occurs over a certain section of pipe. That\u2019s an easy way to isolate, specifically, where the problem exists.\u201d<\/p>\n

Clarke catalogs the hydraulics of a system he\u2019s working with. \u201cI start by figuring out what the yield of the water source is, what size the main line is and how far away from the assignment it is because distance affects the pressure that I have to work with.<\/p>\n

Then as I\u2019m running the zone or zones I\u2019m looking at, I\u2019ll do a basic head count and estimate how big the zone is in gallons per minute. I compare that to the water source and the mainline size and start getting an idea of how much water I have to work with, and what I can get away with.\u201d<\/p>\n

Clarke adds that \u201ca lot of installers don\u2019t know much about design hydraulics. They won\u2019t take into account the pressure loss over distance that friction causes and that throws off their piping calculations.\u201d<\/p>\n

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DON\u2019T FORGET: There are only three areas that can go electrically wrong in a conventional, non-two wire system: the controller, the solenoid or the field wiring.<\/p><\/blockquote>\n

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Electrical problems<\/h2>\n

When Chris Pine teaches troubleshooting classes for the Irrigation Association, he explains that there are only three areas that can go electrically wrong in a conventional, non-two wire system: the controller, the solenoid or the field wiring. \u201cTo isolate which one of those it is, we test the power as it moves from the source all the way out to the solenoid. We check to see whether the controller is producing power output for each one of the valves.\u201d<\/p>\n

\u201cIf it is, next we look at the field wiring and the solenoid,\u201d continues Pine. \u201cWith a multimeter, we test the resistance of both. If there\u2019s a fault, and both the field wiring and the solenoid test bad, at that point we\u2019ll go to the solenoid and see if that\u2019s really the source of the problem. If the solenoid really is bad, then we know it isn\u2019t the field wiring. But if the solenoid is okay, then we know it is the field wiring.\u201d<\/p>\n

Clarke says, if you don\u2019t have a funny ohmmeter reading and you know for certain that a wire goes to the area you\u2019re working on, then you need to figure out what happened to that wire. It could be a bad splice or damage to multiple wires.<\/p>\n

The next thing, Pine says, is to look at context clues. Are other wires also giving zero readings? Or are there wires running valves that are in that same area? Sometimes it\u2019s easier to find the next closest valve and try and pick up some clues from the wiring in that valve box or manifold; that\u2019s often simpler than hooking up a tracker from the controller and seeing what happens from there.<\/p>\n

Clarke says, \u201cSometimes, you have to kind of break things into pieces. If you\u2019re far enough away from the controller to where you\u2019re losing signal, there might be a splice or junction box between the controller and the zone you\u2019re working on where you can identify the wire you\u2019re looking for and hook your equipment up to it to improve your tracking signal, or just take your readings from there.\u201d<\/p>\n

Troubleshooting irrigation systems isn\u2019t easy, but if you\u2019re a person with an investigative mindset and a bent for problem-solving, it can be a very satisfying and challenging task. And the kinds of skills involved in it are very much needed. Armed with education, certification and experience, you can be excited every day to shout, \u201cthe game\u2019s afoot!\u201d<\/p>\n

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A knowledge base worthy of Holmes<\/h3>\n

After decades of working in the industry, these professionals have learned about hundreds of irrigation products and their histories. They also know how installers in their area typically put things together, making them able to look at a system and tell you exactly who installed it.<\/p>\n

\u201cThere are some companies in our area that I\u2019ve followed long enough to know that they only use 1- or 2-inch pipe, and nothing in between,\u201d says Clarke. \u201cIf I recognize that a system\u2019s been built by them, I can make some pretty good guesses about it.\u201d<\/p>\n

He cites as a for-instance a few installers in his area that he describes as \u201cseparatists.\u201d \u201cThese guys won\u2019t listen to anyone,\u201d he says. \u201cSo, I\u2019ll see the same problems, over and over again, things that would be easy to avoid if anyone at those companies knew how to do math.\u201d<\/p>\n

Certain products have distinctive types of failures that are seen repeatedly in the field. \u201cThere\u2019ve been times where a pressure problem that seems unexplainable is really just a valve malfunction,\u201d Clarke says. \u201cSome valves nearly always fail in the partially closed position as opposed to being stuck open. But you have to know which model valves do that particular thing.\u201d<\/p>\n<\/div>\n

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The troubleshooters\u2019 toolbox<\/h3>\n

There are, indeed, some very cool tools the irrigation industry has developed to aid in troubleshooting. Companies like Greenlee, Rockford, Illinois, Armada Technologies, Caledonia, Michigan, and others make everything from multimeters and tracing probes to very advanced suites of devices. They include things that can make solenoids rapidly open and close, producing a \u201cchattering\u201d sound that helps in locating valves.<\/p>\n

Underground wire and valve locators are valuable tools if you do not have an as-built drawing of the system and you need to find the wire path and the control valves. Ground fault locators can help you find wires that have been nicked or broken and are leaking current into the earth. These tools have sensitive wands that one sweeps over the earth similar to a metal detector to trace wire, find valves and locate faults.<\/p>\n

While by no means a comprehensive list, some of the other tools irrigation technicians and contractors keep on their trucks include:<\/p>\n