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Precision
03-24-2007, 03:43 PM
I do irrigation maintenance on a commercial system. 12 zone with a Rainbird ESP-12 LX plus controller and an electrical pump relay. The pump (3 hp / 240 volt) runs. System is a remote selonoid valve system (not an index valve system).

Primarily I adjust the timer for the seasons, fix broken or clogged heads, fix the spray pattern or whatever. But I also do first line of defense when something else goes wrong.

I think I know what the problem is but I want to double check and make sure I didn't forget something simple.

Problem:

At first glance it appears that no water is exiting the heads on any zones. I checked the pump to make sure it worked. At first it didn't, but there is a switch between the relay and the pump and someone had switched that to off. I switched that to on and I fired the pump, I could hear and feel water in the pump but no visible water coming out from any sprinklers, regardless of which zone I tried.

I tried multiple zones in case one had a sticking valve. I also went to a remote box and manually opened the valve. When I did this, I was right next to one of the head on that zone and noticed water flowing from the head, just enough to spray past the nozzle of the pop-up (1 inch max) then it surged up to (3 inch spread) then fell back down to 1 Inch.
I checked for prime at the pump and re-primed it. No significant change.

I went to each of the well heads (1 1/2 inch pvc 13 feet apart) and checked for flow vibration and didn't really feel or see any. So I shut down the pump then removed the "priming cap" and filled the furthest one from the pump with city water and capped it, then filled the nearer one with water and capped it shut.

Still no significant flow at the heads, but now I can hear and feel water in the well pipes. then I reprimed at the pump. Still no volume increase.



My thoughts:

1. the impeller is broken and isn't pumping water properly
2. the circuit lost a leg and my pump is only running on 120 and doesn't have enough power to push the water
3. We have had almost no rain in the past 2 months and maybe the wells are fairly close to dry.

I will be checking #1 and #2 tomorrow. I didn't have the correct tools to do that today. Usually it is just some genius turns off the controller box.

Really hoping it isn't #3

Anyone have any other ideas of what I can check or what it might be.

Thanks in advance for any suggestions.

And this is florida and it is most likely a shallow well system.

Mike Leary
03-24-2007, 03:55 PM
Does the system have a master valve? Did the backflow boys leave the
the ball valves closed after testing?

Precision
03-24-2007, 04:09 PM
Does the system have a master valve? Did the backflow boys leave the
the ball valves closed after testing?

In florida, we don't have to worry about freeze issues, so no blowing and shutting off the system. We run irrigation all year long.

I can't think where a master valve would be. No ball valves at all (above ground) between the two wells and the pump. Each well has an in-line one way valve to stop back flow but that's it.

This is an existing system and worked fine 3 weeks ago when I adjusted for spray pattern. Damn UPS and FED-EX trucks always running over a couple of sprinklers (on the other side of a 6 inch concrete curb).

Wet_Boots
03-24-2007, 04:31 PM
A vacuum gauge would come in handy here. See what's happening on the suction side of the pump.

Precision
03-24-2007, 04:48 PM
A vacuum gauge would come in handy here. See what's happening on the suction side of the pump.

ok, how would I utilize that assuming I can get my hands on one?

Do i need to break the pipe really close to the pump or anywhere between the well and the pump.

I assume it is just like a pressure gauge but works in reverse.

Mike Leary
03-24-2007, 04:51 PM
Have you checked to see if've you've got 24 volts @ the pump start/master
valve output @ the clock? You're right about the vacuum gauge Boots.

Mike Leary
03-24-2007, 04:53 PM
Sorry...did not read your thread enough, if you're firing from the clock,
pump start is fine.

Wet_Boots
03-24-2007, 04:58 PM
Pumps have a small plug on the suction side. Connect the gauge there. (buy one at Grainger) ~ In feet of water, you won't likely read higher than 25, before cavitation begins. You are concerned with suction leaks here, for one thing. Low water table is something else entirely. Can you measure it in either point?

Precision
03-24-2007, 05:14 PM
Pumps have a small plug on the suction side. Connect the gauge there. (buy one at Grainger) ~ In feet of water, you won't likely read higher than 25, before cavitation begins. You are concerned with suction leaks here, for one thing. Low water table is something else entirely. Can you measure it in either point?


Ok the plug is there. I saw that when I was looking for the priming plug (doesn't have one).

Can I measure it in either point? Not sure what you mean.

the plug is there. I can put the gauge on there, should be room in the pump house. Where would the other point be?

Low water table is the issue I don't have any clue how to check for other than by eliminating everything else.

I am still hoping it is running on 120 instead of 240. Easy fix.

Wet_Boots
03-24-2007, 05:22 PM
By 'point' I mean well point - do you know what your water table is? You may be near a depth beyond what your pump can work with.

Precision
03-24-2007, 05:54 PM
oh, I thought you meant point as in location, oops. But no I really don't know. I was not involved in the install. It was done a few years before I started on the property. In truth, I don't even know if it is a shallow well or a deep well. Most of them around here are shallow, but you never know.

If I understand what you are saying, you mean that the well is 25ft but normally the water table is at 10' but now due to dryness the table is down to 20' and that is causing suction issues.

We are so close to sea level that most places where you dig deeper than 4 feet you begin to get water intrusion and I don't think many shallow wells go much lower than 25'

Mike Leary
03-24-2007, 06:02 PM
Boots, you're thinking the water table has dropped in the past three weeks
& he's pulling nada....The sound he's hearing is the pump, not water?

Wet_Boots
03-24-2007, 06:12 PM
Water tables do drop, and this is a shallow well by the details given here. How close to the area of poor/non performance the water table is, is a detail I'd want to know, if it's a system I care for. Besides lowered water tables, there could be a clogged well point. Those just kind of sneak up on you. I would still be looking for a suction leak, though. That's a good starting point.

Once you have a vacuum gauge, there's some sense in getting suction readings on any shallow well pump you care for, just to have the numbers on hand, to aid in diagnosing future problems.

Mike Leary
03-24-2007, 06:22 PM
We do carry a vacuum gauge also, if you're dealing with pumps, it's better
than sex,almost. Will be interesting to see if it's a suction leak. Time for a
draw-down test after that.

Precision
03-25-2007, 09:21 AM
We do carry a vacuum gauge also, if you're dealing with pumps, it's better
than sex,almost. Will be interesting to see if it's a suction leak. Time for a
draw-down test after that.

both of you guys, thanks.

Can't get a vaccuum guage until tomorrow (monday).

will be checking the impellor (disassembly) and checking the power issue today.

I thought about a clogged well point, but having 2 wells should reduce the likelihood of that, although if one doesn't supply enough water for the system, I guess that would be enough of a problem if one got clogged.

Aside from drilling a new well, what do you do with a clogged well point? How do you fix that?

Wet_Boots
03-25-2007, 09:37 AM
Clogged points get water forced back through the screen, then pumped again. If you have a fine mesh strainer on the outlet of the pump, you can see some of the material you're freeing up, and about when you've freed all you're going to. A two-point setup would be more work.

If you learn what the water table is, you can see whether you're in a situation where a newer, deeper well is in order. At around 20 feet of lift, a shallow well pump's performance drops, and a deep well setup becomes more efficient.

PurpHaze
03-25-2007, 10:33 AM
I can't think where a master valve would be. No ball valves at all (above ground) between the two wells and the pump. Each well has an in-line one way valve to stop back flow but that's it.

The master valve would be an automatic valve that is installed on the main line prior to any of your zone valves. It is fired by the clock anytime the clock is on and allows main line water to reach all the zone valves. When the clock is off the master valve is shut down and doesn't allow water to the zone valves... kind of a safety feature in the event one of the zone valves hangs up and doesn't shut down.

You can check for the presence of a master valve at the controller as it needs a common and control wire going to it just like a zone valve. Most newer controllers have a connection point on the controller bus board or module marked "MV" and if you see a wire on that one you will have a master valve in place.

I'm not good on pumps and haven't read the entire thread thoroughly but have you checked the outlet side of the pump to make sure you're actually getting water through it to eliminate pump/well problems?

Dirty Water
03-25-2007, 01:02 PM
You can check for the presence of a master valve at the controller as it needs a common and control wire going to it just like a zone valve. Most newer controllers have a connection point on the controller bus board or module marked "MV" and if you see a wire on that one you will have a master valve in place.

Or in his case, a Pump start relay :)

PurpHaze
03-25-2007, 03:37 PM
Then he'll have two control wires... one to the pump relay and one to the MV. :)

Mike Leary
03-25-2007, 04:01 PM
I see you guys have returned to the master valve question, not using R.B.
clocks, should it show a fault on the m.v./p.s. circuit if the solenoid is going
south? Wait a minute, he is south.

Precision
03-25-2007, 07:31 PM
Or in his case, a Pump start relay :)
My electrician and I went out today and tackled all the possible electrical problems.

Not a problem with the 240 having dropped a leg.
The relay switch is fine. The circuit is fine.

Got to talk with the POLICE because my client forgot to disable the alarm before I got there. But they let me go "this time". :)

Not a problem with the actual pump impeller, in fine shape. The bearing is showing a tiny bit of wear (side load) Inner pump bearings may be starting to show their age.

with a good priming of the pump, it moves water quite well but not up from the well in any quantity.


In talking with my client, to get the police to chill. I went over what we had done and what I thought the likely remaining issues were and he told me not to worry about it, I had gone way beyond what was specified in my contract and he would call someone on Monday and to send him a bill for the electrician and my extra work.

Hopefully, I will get a report on what it turns out to be, then I can look smart or shame faced about what it was, but at least I will learn something.

Thanks for all the help.

Mike Leary
03-25-2007, 07:37 PM
Don't fret, you went the distance, you blew alot of (unbilled?) time talkin'
with us, you cared...good for you! The hard core would STILL like to know!

PurpHaze
03-26-2007, 09:14 AM
... with a good priming of the pump, it moves water quite well but not up from the well in any quantity.

Sounds like you've done a good job of narrowing down where the problem is. Boots appears to be spot on that either the water table has dropped or there is something wrong on the intake end. I'd leave it to a pump specialist now.

Precision
03-26-2007, 11:04 PM
Don't fret, you went the distance, you blew alot of (unbilled?) time talkin'
with us, you cared...good for you! The hard core would STILL like to know!
I am one of those hardcore. I will update when I know. Hopefully, (for the grass's sake) by friday.
It is billed time, just not extra billing. But all and all, I get paid ok to work on their irrigation.

Precision
03-30-2007, 03:42 PM
client called today.

took the Irrigation guy 2 days and 3 trips to figure it out and fix it.

Seems I was right about the pump needing a new seal and membrane, but the main problem was 3 yes THREE remote valves all got stock OPEN.

I never would have thought of that, not to mention I don't have the wand to locate them.

Client is happy and the system is running, so it is all good.

Question. What (other than dumb luck) would cause 3 zone valves to freeze open in the two weeks since I last checked the system?

Mike Leary
03-30-2007, 06:11 PM
Dumb luck, coincidence? That's what I love about this biz..so many possibilities about what caused what. The valves were installed at the same
time, I assume..normal wear, diaphrams worn out..remaining valves suspect
& should be checked, dirt somehow getting into the system, solenoid ports
plugged..only a couple of ways to fail, what did the sprinkler boys tell you?
You've got more valves in the field & they could be planning their escape.

Wet_Boots
03-30-2007, 06:18 PM
All it takes is one valve, and others can follow, since you can't bring up enough water pressure to close them.

This points up the need to isolate the system from the supply, when considering the pump operation. There should be a shutoff valve after the pump, so the system can be removed the equation, and an outlet between pump and shutoff, so you can see the pump operate on its own.

That the valves should be in boxes with access covers is obvious, and even more obvious is the need for the control valves to have flow controls, throttled down, to insure more reliable closing.

Mike Leary
03-30-2007, 07:15 PM
Let's not have the pups using the flow controls as a shut-off, tho; We've
replaced a ton of guts that way. Throttle the flow control down until you see
a decrease in application...throttle-up 1 turn & the valve should have no
problem closing.

Wet_Boots
03-30-2007, 07:27 PM
That is one nice thing about the screwdriver valve throttles, nothing to tempt the meddlers. The old Richdel AS valves had removeable throttle handles, so they weren't easy to fiddle with.

Mike Leary
03-30-2007, 07:44 PM
"Fiddle" is the word..they made us a ton of work, same with controllers.
Plus, we gained a client!

bicmudpuppy
03-30-2007, 11:30 PM
hmmm, dumb luck....................like bad karma is never just "luck" good or bad.

What could have cause near simultaneous failure of 3 zones? I tell customers all the time that they don't usually need to panic when the first one goes, but when the second one goes, be ready to fix them all. Did you see the failed valves? A shallow well that sucked a batch of sand or silt could have caused many vales to stick, and could have left enough trash in the system to cause many more to stick later. A quick jump in pressure for any reason (valve was slow to open or a valve was slow to close and then hammered off) could have caused some weak diaphrams to fail. And the list could go on and on and on and on and on and on and on :) :) :)

And btw, with the new golf gig, I probably had 20 weeping and stuck valves at start up this year. I cleaned and changed diaphrams on 2 valves so far. The rest have been cured by a miracle from God (or you could give me credit for staggering the clocks and cycling the crap out of each of them to clean them out). I still have 4 that weep. Holding off leaving the system presurized till I find time to rebuild those.

Precision
03-31-2007, 12:13 PM
Thanks guys.

I did not get to talk to the sprinkler tech. I only got to talk to the Ops manager of the site and he said the tech was not too verbose over what he did.

This system does not have a master valve at least that is obvious. I really think this system was put in on an extreme budget. There are lots of things that just don't make sense and it definately does not have head to head coverage in many places, nor (in my opinion) large enough diameter pipe on the longer runs. Also many of the rotors originally had WAY too large of nozzles on them. Some running 6 or 8GPM with others on the same zone running 2 GPM with the same coverage area. Some heads an inch above grade, others 2 inches below grade (I fixed all those problems) and almost all of them on cutoff risers. No flex pipe or swing joints. I fix that as I replace sprinklers.

But most of the time the system works. And as far as the owner of the building is concerned, it's in and failures are my client's responsibility.

Considering our drought situation, I have to believe it must have been sucked in sand. Or it could just be time. these are the first 3 valve failures.

Thanks again.

Mike Leary
03-31-2007, 06:42 PM
"Cut-off risers" says it all. It's like showing up at a new site & opening up
the clock.....if it's a rats nest w/the wiring, it 's not going to get any better in
the field!