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Troubleshooting Zone Wire(s)

Discussion in 'Irrigation' started by MEXANDME, Aug 14, 2013.


    MEXANDME LawnSite Senior Member
    Messages: 396

    Last valve on the run, i.e., only the common and one zone wire gets to this valve.

    Getting 16 volts to the valve so valve will not open.

    Valve opens fine with valve activator.

    27.3 volts leaving the clock.

    Is the problem more likely to be in the common or the zone wire or is there anyway to tell?

    The irrigation wires parallel the electrical wires feeding the house all the way to the valve so I am getting a lot of static from the electrical. I was able to find the valve but cannot distinguish where the fault may be.


  2. Cape Atlantic Landscaping

    Cape Atlantic Landscaping LawnSite Member
    Messages: 37

    you need to do a resistance test (Ohms) at the controller you should see 20- 60 ohms
    second go out to valve solenoid and ohm that out to the correct numbers above

    my guess would be bad splice at solenoid wire connection to field wiring

    cut and trim new ends and reconnect splice then check numbers again

    to actuate a valve 24-27 volts is preferred

    when trimming wires check for corrosion in wire itself, it should be clean like a new penny
  3. Cape Atlantic Landscaping

    Cape Atlantic Landscaping LawnSite Member
    Messages: 37

    I should add when you test field wiring at controller its best to test wires with controller unplugged and battery out of controller or disconnect common and zone wire from panel
    like I said before, bad splices are all to common. That is probably one of my biggest complaint's is crappy splices, interior wire nuts no grease, black tape and so on.
  4. Cape Atlantic Landscaping

    Cape Atlantic Landscaping LawnSite Member
    Messages: 37

    how long of a run is it to controller ? if under lets say 50 ft. run a single wire out to valve from controller and hook up to solenoid one at a time. replacing one for the other and turn it on a see what happens.
    that would tell you what wire is possible bad.
  5. 1idejim

    1idejim LawnSite Fanatic
    Messages: 11,318

    Mex, you have another goober here.

    This all depends on how you take your measurements.

    I kinda make it a rule to check the common at the last working valve before getting too wound up.

    If you didn't get lucky then go to the clock and take resistance measurements of all zones.

    Next remove the first zone wire and measure the static voltage of the zone.

    Put the zone wire back and measure voltage on it and all of the zones under load (dynamic).

    If you have the ability to measure the current draws on all stations, do it and write all of these measurements down for future reference.

    If your resistance measurement is 150 or above then you look at loose connections.

    If the resistance is below 7 ohms look for a short.

    To find ground faults, use a short to earth measurement. Greater than 700,000 ohms and you are ok, below 700,000 you have earth contact. Way below up to and including 0, you see the severity of the compromise.

    When you took the in field voltage measurement did you exclude the common or did you measure the voltage to ground?

    If the valve wire was measured to ground, look at the zone wire.

    If the common was included you can confuse yourself Mex, read the simplest numbers.

    I don't like to guess so i won't - you have my number anyhow. Call me if you need some help.
  6. CAPT Stream Rotar

    CAPT Stream Rotar LawnSite Fanatic
    Messages: 6,193

    Is it multi strand or single strand?
    as said before ohms.
    STE- on both com and field wire.

    good luck gotta love someone who doesn't quit! play on player.

    MEXANDME LawnSite Senior Member
    Messages: 396


    Thanks for your feedback/help!

    We have had three days of solid rain here so I have not been back yet.

    Homeowner lives out of town and will all the rain....no rush to get back.

    I will keep you posted.



    MEXANDME LawnSite Senior Member
    Messages: 396


    Thanks again for your help!

    With the zone turned on at the clock, and the wires disconnected from the solenoid at the non-working valve, I read 16 volts across the zone wire and the common.

    I read 21 volts across the zone wire and a ground probe. So, I assumed it was the common that was the problem.

    I located the next working valve back toward the clock which was only 45 feet from the non-working valve. I laid out a temp common on the ground between the two locations and the valve then worked from the clock.

    Since the existing wiring was in the same trench with the power and I was getting lots and lots of static from the power and the entire areas was full of 30-year old shrubs and trees, I "wimped out" and just replaced the last 45 feet of wire rather than trying to find/fix the fault.

    Do I get an "F" or maybe just a "D-"?

    Thanks again for your help!

  9. ArTurf

    ArTurf LawnSite Platinum Member
    Male, from Ark
    Messages: 4,397

    I'm not the expert Jim and some others are but I'll give you an b+. I think you understand the principles and it would be difficult to locate the compromise without a fault finder.
  10. 1idejim

    1idejim LawnSite Fanatic
    Messages: 11,318

    It is working and that is what you were after. I would be wondering about a 6.3 vac loss if the system is ave residential size though.

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