pump start relay bad? (hunter sprinklers)

Discussion in 'Irrigation / Sprinkler Forum' started by insane_drummer, Oct 4, 2011.

  1. insane_drummer

    insane_drummer New Member

    Messages:
    5
    Location:
    wichita, ks
    I have a hunter sprinkler system for my lawn. One day it was working great, the next it won't turn on. I set the controller to 'manual all zones' and turn it on. The display shows its running, but the sprinklers never come on and I never hear the pump start relay click like I usually do. I have checked all the breakers and nothing has been tripped.

    Is my pump start relay bad? Is there a way I can manually force the pump on or troubleshoot the psr?
  2. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Messages:
    1,328
    Location:
    Columbus, OH
    You could check continuity across its contacts when its made. If it tests good, open the breaker, jumper the contacts and see if it starts up when the breaker is closed.
  3. BRD

    BRD New Member

    Messages:
    53
    Location:
    northeast
    It could also be a simple matter of the rain sensor having you shut down. Do you have a sensor and did it rain?
  4. insane_drummer

    insane_drummer New Member

    Messages:
    5
    Location:
    wichita, ks
    I do not have a rain sensor.

    Here is my controller:
    [​IMG]

    Here is my pump start relay:
    [​IMG]

    In the above picture I measured voltage on each of the wires marked with a yellow arrow. These wires are the wires coming from the controller. I did not see any change in voltage from when the controller was off to when the controller was set to 'run'. Should I see a change in voltage or would it just be a quick spike to turn on the pump and then return to normal?

    [​IMG]

    What contacts are you referring to?
  5. BobL43

    BobL43 DIY Senior Member

    Messages:
    1,783
    Location:
    Long Island, NY
    the voltage to the coil of the pump relay should measure 24Volts AC when the pump should be running. That voltage is supposed to come from the sprinkler controller when any zone is supposed to be running. When a zone is on, the voltage to that zone solenoid valve should be 24 volts AC as well. Have you measered the voltages to the zone valves at the controller? On the controller, if Zone one is on, you should measure 24 volts from the C (common) terminal of the controller to the zone 1 terminal of the controller. Same for any other zone. And, at the same time, the 24 volts should be between C and the P terminal of the controller. The fuse in your photo is OK, I assume? Is there 24 volts AC coming into the controller from the transformer (measure the actual voltage).
  6. insane_drummer

    insane_drummer New Member

    Messages:
    5
    Location:
    wichita, ks
    The fuse is totally clear.

    I measured the leads coming into the controller from the outlet on the wall (volt meter set @ 20VDC) and the readings bounced around from .07 to .09.
    I turned the controller on and it didn't change the input readings.

    With the controller on and set to zone 1, I measured from the common (C) to zone 1 and the reading was 0.00.
    With the controller on and set to zone 1, I measured from the common (C) to the pump start relay (MV) and the reading was 0.00.

    I beginning to think that something is wrong with the controller. Does this sound right?
  7. BobL43

    BobL43 DIY Senior Member

    Messages:
    1,783
    Location:
    Long Island, NY
    Fuse is Clear?


    First of all, you need to have your meter set to read AC volts, not DC volts.

    You say the fuse is completely clear; you mean there is no fine wire in it going from one end to the other? Its best to remove the fuse and check it for continuity with your meter set to ohms or continuity testing. It should measure 0 ohms. If it is blown, it will not make the meter move or beep. If it is blown, something shorted out and caused the fuse to blow.
    Fuses are very cheap. Try another fuse and see if it blows. I would think that the controller would not be the "likely" cause of blowing the fuse, but it is possible. If the new fuse blows, try disconnecting all the wires from the controller to each zone and the pump relay, then put another new fuse in. If it blows, then yes, I think the controller is bad. If not, reconnect each zone one at a time, and then the pump relay wire (all done at the controller) and see what happens. If all is OK for instance untill you reconect zone 3, then the wiring to zone 3 or its valve solenoid is shorted. As I said these fuses are cheap, just do NOT install a larger amerage fuse than what should be there!!!!!
  8. insane_drummer

    insane_drummer New Member

    Messages:
    5
    Location:
    wichita, ks
    heh heh..... yeah there was no wire..... I was looking for something black or burnt for some reason. I replaced the fuse and the system started again. I went through each zone and started it successfully without blowing the fuse, so i don't know what could have done it.

    I appreciate all the assistance - it was good information.
  9. BobL43

    BobL43 DIY Senior Member

    Messages:
    1,783
    Location:
    Long Island, NY
    You are welcome. I am not a sprinkler tech, but have been an Industrial automation controls tech for over 30 years and have my own sprinkler system. Glad to have helped. Now that I am semi- retired, I do tech support over the phone, so this was kinda like what I do, but on a "much more basic" system.
  10. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Glad you are back running. Here is a more straightforward description of how to test that.

    Measure between the two top terminals....should be you 120 volts. In this case, you would have had zero and that told you to check the fuse.
    If you had the 120 there, turn on the sprinklers and check across the two "load" terminals. That should be 120. If it IS, pump bad, if not, then check for 24 volts between the red and white. If you have 24 volts, relay bad. If not , timer bad.

    Be careful about checking voltage to other reference points, because you have to really understand the circuit diagram to intrepret those readings. Always start by checking for power where it should be.
  11. BobL43

    BobL43 DIY Senior Member

    Messages:
    1,783
    Location:
    Long Island, NY
    But the problem was not in the relay (contactor box). Nor was the controller itself bad. I am not familiar enough with that controller to know if the fuse is only for the loads on the controller or actually is used to protect the controller itself. I personally believe that it is for the loads, like the zone valves and the pump relay, and one of those caused the low amperage glass fuse to blow. A sticking plunger in a valve solenoid will actually cause the solenoid to pull too much current. When the plunger fully enters the solenoid, it draws less current than when the plunger does not enter fully into the coil, a function/effect of magnetic saturation.
    Your description of how to trouble shoot the relay box is exactly correct, except that the 120 volts comes from the box to the right of the relay box and the fuse or circuit breaker in that box feeds the 120vac to the relay box top 2 terminals.

    Edit: The original post says the controller shows it's running, so the fuse is only for the loads, and the controller will have power for its logic and display even with a blown fuse
    Last edited: Oct 7, 2011
  12. insane_drummer

    insane_drummer New Member

    Messages:
    5
    Location:
    wichita, ks
    This is why I didn't give more thought to the fuse in the first place. I figured that since the controller was 'working', that it must be something else. A perfect example of over complicating something by not checking the basics first. Thanks again for everyone's input.
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