Irrigation System Blowing Fuses

Discussion in 'Homeowner Assistance Forum' started by laubo, Nov 23, 2005.

  1. laubo

    laubo LawnSite Member
    Posts: 8

    I have an irrigation system that has a RainBird ESP-6TM controller with 3 DV-100 electric control valves. It worked fine for the first 18 months of its life, and then started blowing fuses. This is what I've done to try to correct the problem:

    1. I rewired the electric control valve connections using water-resistant wire nuts. The system worked fine for a while and then started blowing fuses.

    2. I replaced the electric control valve for zone 1. (I had disconnected the valves and reconnected them one by one -- zone 1 blew a fuse as soon as I turned it on from the controller.) The system worked fine for a week and then blew a fuse.

    3. I replaced the fuse, ran all three zones for at least five minutes from the controller's manual button, with no problem. I let the system run that next day through a normal cycle -- 1 hour each zone, with no problem. The next normal cycle it appears that zone 1 ran OK, and the fuse blew either at the start of zone 2 or during zone 2, but I'm not sure.

    I can put a good fuse in and run each zone for at least 5 minutes from the controller using the manual button, with no problem, but I've decided to not waste any more fuses trying to run the normal cycles.

    I'm using 1/2 amp, 250v, fast-acting fuses that I picked up a Radio Shack.

    After writing this, it occurred to me that perhaps the controller could be causing the problem when I'm letting it run the system on a normal cycle, or should I focus on the electric control valve?

    Here's something else that may have a bearing on the problem, but I'm not sure. In the past, when it rained, the control valves were submerged for at least two days after the rain. I figure they must be designed to be water-proof, but who knows? I've done some work to prevent this from happening, in the hopes it might help.

    Thanks for your help,
    Bob Morris
     
  2. 402-676-Lawn The answer

    402-676-Lawn The answer LawnSite Member
    from omaha
    Posts: 5

    Did you replace the solenoid with the valve
     
  3. laubo

    laubo LawnSite Member
    Posts: 8

    I replaced the whole valve including the solenoid.
     
  4. YardPro

    YardPro LawnSite Gold Member
    Posts: 3,563

    nick in the wire somewhere..

    i have seen controllers have a "bad zone" but yours sounds like a bad wire..
     
  5. laubo

    laubo LawnSite Member
    Posts: 8

    You know, I thought a nick in the wire, too, but wouldn't the nicked wire have to be underwater to go to ground and cause a short? The thing that bugs me is that the system ran fine for the first 18 months. I'll be checking the wiring in the "hole" using a magnifying glass. Is there a problem using fast-acting fuses?
     
  6. Az Gardener

    Az Gardener LawnSite Gold Member
    Posts: 3,899

    I would go to a pin-tight or some other water proof connector as opposed to a water resistant connector. I would also take the face of the controller back to the distributer Ewing, John Deere who ever, and tell them this thing keeps blowing fuses, they will most likely give you another. Most controllers have a 5-yr warranty. I had the same thing happen with a 24 station total control last year after the 2nd time it happened I took it in and got a new one, no questions asked. If you want to continue to troubleshoot disconnect the wires to the valves and run the auto cycle and see what happens. That should tell you if its a valve issue or the clock. Or a power side problem, possible power surges? Just throwing things up to see what sticks.
     
  7. laubo

    laubo LawnSite Member
    Posts: 8

    Thanks for all the help. At least I think I've been able to eliminate some things. I disconnected the wires to the valves and ran the controller through a couple of cycles with no problems. When disconnecting the leads I discovered the hot wire from the transformer was loose in its socket. Eureka, I thought, I've found the problem.

    I reconnected the valve wires, set the controller to run every day, and turned on the controller. It ran fine for three days and blew a fuse on the fourth day. I've replaced the fuse, disconnected the rain control lead, just in case that's the problem, and will try again.

    I'll probably end up replacing everything trying to solve the problem.

    By the way, does anybody know if fast-acting fuses might be the problem?
     
  8. Nick in the wire would be my guess....there is always moisture present in the "earth" causing the wire to go to ground.....

    Look in the manual that came w/ the timer for the proper fuse and only use that fuse.

    Check your connections in your common wire.....if it is doing it on different stations, then it must be a common or ground wire problem.

    Good Luck.

    If you know how to use an ohmeter, maybe I could help you a bit more.
     
  9. Critical Care

    Critical Care LawnSite Bronze Member
    Posts: 1,654

    With a month having gone by, I’m wondering what became of this situation?

    FWIW, the ESP TM controllers aren’t real hefty and don’t offer the current handling capabilities as some of the other controllers have. The max output per zone is around .6 amps, fused at .5, and your DV-100 valves are drawing roughly .3 amps when powered up. It would be interesting to put an ammeter in line with one of the zones to see the actual current being drawn.

    Wire size, wire length, poor connections, and damaged wires could all lead to problems – especially in a smaller controller. The controller runs for a while, things start to get wet – perhaps around where the cable and valves are – and then suddenly the controller is looking at a load that it doesn’t like. The resistance of the load has now dropped and extra current is being drawn from the controller. One zone in operation teeters on the edge of blowing the fuse but then shuts off. The next zone powers up, but with the extra inrush of current required to activate the solenoid the controller throws up it’s arms and says, “Dude, that’s it! Consider me on strike.” Poof.
     
  10. Critical Care

    Critical Care LawnSite Bronze Member
    Posts: 1,654

    Oh... the question about fast acting fuses. Well, I doubt that would be a problem as long as you are well below that threshold limit.

    When your solenoids latch, you're talking an extra .1 amps inrush current. Not a whole lot compared to what happens when some compressors or motors start up. Sure, because of problems or system limits, it could be the straw that breaks the camel's back. But lets face it, a slow blow .5 amp fuse probably isn't going to help if the constant current flowing through it is in excess of that amount.
     

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