Station breaker Randomly Trips

Discussion in 'Irrigation' started by Richie1, Jul 2, 2007.

  1. Richie1

    Richie1 LawnSite Member
    Messages: 37

    Hi folks,

    This is my first post and I'm happy to be part of this forum.

    I'm having issues with my 10 station sprinkler system. It was originally installed in 1967. Some of the valves are brass with Moody solenoids, some are plastic cup valves that I can't identify.

    The original controller was upgraded in 1974 to a Weather Matic SSR-10 and recently stopped working in automatic mode. So I installed a new electronic controller I had on hand that was purchased from Home Depot. It's a WaterMaster 12 Station model 57112 along with one of the station valves that had a bad solenoid. I think this controller is really cheaply made.

    As soon as this new controller was up and running, the electronic breaker would trip radomly on several of the stations. This NEVER happened with the original controller. Sometimes it would trip, sometimes it wouldn't. So I opened the outdoor valve boxes and re-spliced all the station wires and commons. It made no difference.

    This morning, I took Ohm readings from all the stations directly from the control box which is 70 feet away from the valves. All wiring is original as installed in 1967 with 14 gauge solid wire, which is in excellent condition. The majority of the valve wiring is run through the basement of the house. I removed the single common wire from the controller and then individually each station wire. Below are the Ohm readings.

    Station 1 - 15 Ohms
    Station 2 - 15.7 Ohms
    Station 3 - 13.8 Ohms
    Station 4 - 13 Ohms
    Station 5 - 25.6 Ohms (replaced two days ago with 1" Toro Jar top model 53708)

    Station 6 - 9.1 Ohms
    Station 7 - 19.8 Ohms
    Station 8 - 15.4 Ohms
    Station 9 - 20 Ohms
    Station 10 - 15.4 Ohms

    Any help or opinions would really be appreciated. Thanks folks.

    BTW....I have on order a new controller from Irritrol. It's the PC12-INT - PC control system
  2. Mike Leary

    Mike Leary LawnSite Fanatic
    Messages: 23,174

    A normal solenoid is good from 15 to 50 ohms. I've never heard of the clock
    you bought...sound like a low-ender, tho. A going south solenoid will appear to be fine until it heats up, then will start to fry. Given the age of the valves,
    sounds like a re-do is in order. Does it trip off the new valve?
  3. Richie1

    Richie1 LawnSite Member
    Messages: 37

    Hi Mike,

    Thank you for your response. Yes, that new valve sometimes trips randomly too. It makes me wonder if there's another common buried close to the valve boxes that I missed or something. Also, I agree with your thoughts on the controller. I believe it was a company that simply put their name on it and isn't really in the irrigation business. That's why I hate purchasing from Home Depot. I did find a link to the same looking controller that Orbit sells. Mine does not have a remote and is a 12 station controller. But from the link below, you'll be able to see what I have.
  4. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    Good move getting rid of that junk controller!

    I personally don't much care for Irritrol controllers, but that PC model is a start in the right direction. Personally I would like to see a residential/light commercial controller that allows an irrigation tech to access the controller from his couch, but maybe that is just a pipe dream. There are some home automation systems that could achieve my pipe dream, but that is altogether another topic.

    For your readings, I believe the accepted range for control wiring is 20-60 ohms. For all the valves that read below or above that I would test the solenoid and replace where necessary, otherwise you probably have a problem with the control wire.
  5. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,764

    Try to read the actual operating current on the various zones. Current is what trips overload circuits.
  6. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    Did a quick search and found this on the Rainbird site that might help you step through the troubleshooting process.

    Boots makes a good point. Problem with the transformer or house wiring at the box/controller?
  7. Richie1

    Richie1 LawnSite Member
    Messages: 37

    Hi Kiril,

    Thanks for the link to the Rainbird tech site. Great information and I've printed it out for reference. Yeah, I can't wait to get rid of this controller. The Irritrol should be here in a few days. I'll get it installed and see how the system works. However, from the information you and Mike have given me, from some of those Ohm readings, new valves or solenoids is in order, especially seeing the reading from station #6. I really wish I could simply purchase new solenoids and not have to replace all the valves. I can't find the Moody solenoids anywhere, likely due to the age of them. The other solenoids I'll have to remove and see if a replacement is still made. I think I'm going to start by unearthing the complete wiring and valves so I can actually see everything clearly. Thanks folks.

    Wet Boots....where would you recommend I take that reading from, inside the valve boxes or from the controller valve wiring connections? Thanks.
  8. Mike Leary

    Mike Leary LawnSite Fanatic
    Messages: 23,174

    One do-dad we carry in the "first-aid" kit is a spare indoor transformer,
    handy for getting the transformer out of the picture, tho I've very seldom
    had transformer problems. I say that clock is going to drive you nuts. Since
    it's random may luck out & find the problem with your VOM, but
    remember when you take a car to a mechanic & it runs fine!:cry:
  9. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,764

    You could disconnect the common wire, and hook up the current meter there. AC current measuring might not be available from a cheapo multimeter. Better yet, but more 'old school', is a clamp-around current meter, if you can find one with low current capability.

    Old solenoids drew more current. Some old valve solenoids will trip most modern controllers, even though the valve is just fine. You end up needing a high-end controller, like a Hunter ICC, just to get the power required.
  10. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    It is also possible the GFCI or AFCI breaker (whichever is appropriate) is going bad.

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