I guess I don't understand Rain Bird panel - valve hum & transformer hot

Discussion in 'Irrigation' started by gdeangel, May 20, 2013.

  1. gdeangel

    gdeangel LawnSite Member
    Messages: 37

    So the system I am going to be working on is all Rain Bird valves (8 zones) & panel, with short (< 3 ft.) underground run from house to manifold box. It was winterized and during the process one of the zones was noticed to be leaking, so the valve had to be manually opened and some debris was found and cleaned out - while I was at it I checked out all the valves for debris, and reinstalled them. Nothing electrical was messed with.

    As is my normal procedure, the master shutoff was closed in the house, but the panel was left on normal schedule so the valves would open and close for a few weeks and clear any residual water before the fall freeze. The owner turned off the control box sometime in December / January, but left it plugged in as usual.

    Anyway, now during spring pre-activation inspection, it was discovered that three of the eight zone valves are humming / hot, and the transformer at the control box is really hot. Confirmed the control panel was set to off. Unplugged the control panel and humming stopped (obviously no surprise there). I don't suspect any damage to the underground control wires.

    I though OFF meant no current to valves. I'm guessing that's not right. #1 what's the best way to deal with this? Should I just tell them, opps, I overtightened the valves and they've been trying to close all winter so your motors and transformers have been slowly frying, or what? Is it likely realistically that this could be from some other problem? #2, do you advise your customers to unplug the control box over the winter?

    Thanks in advance for all help and information!
  2. Mike Leary

    Mike Leary LawnSite Fanatic
    Messages: 23,174

    "Tighten valves" :dizzy: You want to explain the above sentence before the thread continues? To answer another question, I left all my clocks, after winterize, in "OFF", but powered-up to provide a residual amount of heat over the winter,
  3. gdeangel

    gdeangel LawnSite Member
    Messages: 37

    So actually I didn't have to open the whole valve, just remove the solenoid and there was a piece of rubber debris where the solenoid sealing disk would normally shut off the zone. When I cleared the debris I then put the solenoid back in by hand tight until just a little resistance, the flow issue was gone. I'm pretty sure I tested the zone on and off and didn't notice any unusual humming, but honestly I'm not all that up on the electronics of solenoids.)

    The only thing I came up with when I try to think why the solenoids were humming / getting hot was the solenoids were screwed down too tight, so when the motor tried to actuate the disk, there was nowhere for it to go, and it started to draw current and get hot (that's part I'm not so clear on myself, but seemed to fit the circumstances).

    Now of course there could be a short somewhere, but just seems unlikely, probably even less likely than a bad transformer..
  4. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,764

    Solenoids have no motors, and you can't cause electrical issues by over-tightening them.
  5. 1idejim

    1idejim LawnSite Fanatic
    Messages: 11,358

    1) what is the resistance measurement of each zone?
    2) what is the resistance measurement of each solenoid when isolated?
    3) what is the line voltage?
    4) what is the transformer output?
    5) what is the amperage draw?
    Posted via Mobile Device
  6. gdeangel

    gdeangel LawnSite Member
    Messages: 37

    Don't know what all the images are about, but seriously, like I said, I'm not so up on solenoids, but I understand they aren't motors... more electromagnets, and I get now that as they are activated then they draw current -> heat. OK, so normal operation, only one would be activated at a time, that explains why the transformer was hot as hell... too much current running three solenoids at once.

    The idea that the solenoid wouldn't close / open / whatever triggers it to shut was based on the theory of: I remember something done differently last year, so that's probably what caused of the problem. Sounds like it's probably not from the debris issue.... but if you have a solenoid that can't pop open, wouldn't that still cause the magnet to get hot or something like that because it keeps trying to move the plunger?

    But like I said in the thread title, I just don't get why the panel would be activating THREE zones at once (and, incidentally, apparently not the main control valve - which wasn't humming / hot), all while set to "Off". What gives?
  7. 1idejim

    1idejim LawnSite Fanatic
    Messages: 11,358

    answer my questions and you will answer your own.

    until you do, one can only guess.
    Posted via Mobile Device
  8. windflower

    windflower LawnSite Bronze Member
    Messages: 1,111

    What rain bird timer are you working with? You are right "off" means no power to any zone. If 3 zones are getting power at once, especially in the off position it sounds like the timer needs replaced.
  9. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,764

    A damaged controller might well be powering multiple zones, and drawing maximum current from its power transformer.

    Just remember that a controller is a small bundle of processor-controlled electronics, and that the dials and pushbuttons are not themselves switching power on or off, so a dial set to off means nothing, if the processor is zorched.
  10. AI Inc

    AI Inc LawnSite Fanatic
    Messages: 27,060

    What motor are you talking about? A solonoid is nothing more then an electro magnet. Like any other solonoid.

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