12V Pump Wiring

Discussion in 'The Projects Forum' started by Cabin_Crazy, Feb 1, 2011.

  1. Cabin_Crazy

    Thread Starter New Member

    Feb 1, 2011
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    I am trying to wire up a 12V pump. I need the pump to turn on when water hits the top sensor and turn off when there is no water at the bottom sensor.

    I have successfully made a circuit work (Deep Well Pump Wiring.jpg) with a Omron MY4 relay. Unfortunately the 4-wire sensors (http://www.smarthomeusa.com/ShopByManufacturer/gri/Item/GRI-2500/) are not submersible and I ended up burning up my pump.

    I have now purchased new sensors (http://www.aartech.ca/vip1000-h2o-flair-waterguard-water-detector-5-24vdc-white.html) which I hope will be submersible but I don't know how to change my circuit from the above 4-wire contacts to my new 2-wire contacts. Can anyone help me out? I've attached a sample drawing (Deep Well Pump Wiring03.jpg)

    I'm not an electrician. Please explain it to me like I was 5 years old. Thanks!
     
  2. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    Maybe someone will be along who has prior knowledge of these sensors, but if not, you will need to obtain more technical detail about the sensors and publish the info on this thread. For example, the manufacturer of the new sensor (Flair) has a datasheet available on their website, but I was unable to download the datasheet without registering. I did find a datasheet on the Grisk sensor, but I don't know which version of the sensor you are using. In addition, please attach the .jpg file to a post so we can see it.

    I will say that at first glance, it looks to me like the new sensor will still use four wires: two for power and two to the pump. But the datasheet will tell for sure.

    One final note. The contacts on the sensor must have sufficient current handling capability to power the pump. The Grisk datasheet seems to indicate that the contacts there are rated at only 500 ma, which may not be enough. You need to also provide a datasheet for the pump to know for sure.

    Someone here can and will help, but in order to get the right answer, more information on your setup is necessary.
     
    Last edited: Feb 2, 2011
  3. Cabin_Crazy

    Thread Starter New Member

    Feb 1, 2011
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    I was having troubles uploading my pictures. I'll try again here (I couldn't find a help page). Ahh, I think I figured out my error. I didn't hit the "Upload" button.

    OK...

    Deep Well Wiring.jpg - Working circuit but switches broke and are always closed now. With the comments from tracecom I'm now thinking maybe it wasn't because the switches were submersed but maybe because they were overloaded.

    Deep Well Wiring02.jpg - Working circuit but top switch was discovered as broken and always closed. Need to change out switch to new 2-wire switch and try that one.

    Deep Well Wiring03.jpg - Blank wiring diagram for edit

    VIP1000-H20.pdf - New switch specs

    RuleIL500P_Pump - Pump specs

    Grisk Water Sensor - Original sensors used

    Yes, now that I know how to upload. Perfect!

    Maybe the new switches will still require the four wires but they only do have the two contacts (one is "+" and the other "-").

    Your help is much appreciated!!
     
  4. marshallf3

    Well-Known Member

    Jul 26, 2010
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    Quite honestly you need better sensors, there are a lot of them out there.

    Haven't quite figured out why you'd want to do this: "I am trying to wire up a 12V pump. I need the pump to turn on when water hits the top sensor and turn off when there is no water at the bottom sensor.

    If it's for a water well it should be doing the reverse, if it's for a sump pump then it should be doing to opposite. A simple sealed float switch should work well in either occasion and they're all waterproof by design. Most are little more than a mercury switch that floats and the orientation in which you mount them determines how they operate.

    I lived in the country a lot of times and we simply used a pressure switch on the tank.
     
  5. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    It has been a very long time since I worked with relay logic (and I was never an expert) but I think I understand the basic operation of the circuit. It does seem like it would have been easier to use a different method (float switch, e.g.) but that rationale was perhaps clear in the mind of the designer.

    The most serious problem that I see (from the datasheets) is that the contacts in the relay are not up to the job of switching the pump motor. According to the relay datasheet (see attachment,) the rated load of a 4-pole relay is only 1.5A for an inductive load (which the pump motor is.) According to the datasheet for the iL500P, it requires 6A at 12V.

    While you may be correct that the sensors have failed and the pump motor has "burned up," my suspicion is that the contacts in the relay have failed. I would get that checked and corrected before replacing anything else. And because the relay is at the heart of the switching logic, changing it may require a major redesign of the entire system.

    I would also check the pump motor (by applying power to it directly) to know for sure whether it is damaged. While it is possible that the relay contacts welded shut causing the pump motor to run continuously and burn out, it's also possible that only the relay is damaged.

    I hope someone else here on the forum will chime in here because I'm no expert. Good luck to you.
     
    Last edited: Feb 3, 2011
  6. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    So, this was working as you wanted, but quit...right?

    Was this circuit ever tried and did it work?

    So, here you want a design that uses two of the VIP1000-H2O sensors...right?

    Did you design this system, or are you the homeowner who is just trying to get it to work? Is this for a deep well, shallow well, sump pump, or what? This seems like a lot of questions, but I'm asking them in order to try to understand more about your situation.
     
  7. Cabin_Crazy

    Thread Starter New Member

    Feb 1, 2011
    5
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    To answer some questions:

    1. "The pump is burnt up"....the pump motor works. Because the original 4-wire switches stuck on, the pump ran dry for a very long time and wore the impeller so it no longer pumps the 30 or so vertical feet required. I've since replaced the pump with new and have it wired in.
    2. The original circuit with two 4-wire sensors works, the sensors just fused closed or something and no longer open and close (Deep Well Wiring.jpg). The second circuit (Deep Well Wiring02.jpg) also works. I shop tested it and it works. I haven't field tested it because I found in the shop test that the top 4-wire sensor was also not opening. I have since bought the second 2-wire sensor.
    3. Yes, I'm just a homeowner trying to make this work. I didn't design any of these circuits. The electrician that did is gone for a month and I'd just like to get my water pumping. I don't care how we get it working, whether we use these sensors, whether I use the Omron MY4 relay. All I care about is that the system works in the end.
    4. If there are other better sensors out there, please suggest. The reason I have chosen not to go with a float sensor is because I have limited space and I haven't found a float sensor that would work. The deep well is 40' deep, the hole is 3" in diameter and the hole isn't straight (so an open float switch would just rest against the side wall). The pump is just under 2" in diameter so that leaves realistically less then 1" for the sensor. If I could find an encapsulated float sensor that is less then 1" in diameter, it might work. I couldn't find that but I did find these security sensors that seemed like they would fit the job (at the time). Now I don't know.
    5. The system function is simple. The deep well produces a trickle of water, which is all I need. The well fills to a certain level (about 15' below ground level). When the well water hits the top sensor (at about 15' below ground level) I want the pump to turn on and pump the water out until just above the pump level where I want the bottom sensor to turn the pump off so it doesn't run the pump dry and burn the impeller up. The water that is being pumped out of the well gravity feeds into a storage tank for later use. There is a completely separate pump system that supplies the pressure water system.
    6. The contacts in the relay appear to be working fine. That said, I have another relay (new) but the system appears to be working fine. It's just the top relay, now, that doesn't work. I can hear the relay open, now, when there is no water at the bottom contact (the new 2-wire). The pump does stop running. To me, that means the relay is working.

    Hope this helps and answers all questions.

    Thanks in advance!
     
  8. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    I had hoped that someone with some expertise would give you the answer you need, but since that hasn't happened, I decided I would make one more post.

    There is a way to use use two normally open contact sensors to accomplish turning your pump on and off in the manner which you describe. It involves using one set of contacts on the relay to latch the relay in the operated mode. Here is how it works.

    When the water level reaches the lower sensor (L), it closes, but until the water reaches the upper sensor (U), the relay doesn't receive power. This is because the power is routed through both L and U. When the water level reaches U, the relay operates and then power for the relay passes through one set of contacts to the coil of the relay and the relay is latched in the operated position. At this point, it is no longer dependent upon receiving power through U.

    Power to the pump is switched through another set of contacts in the same relay, but there is no electrical connection between the sensors and the pump. Thus, the pump motor is powered and the pump is pumping water; it continues to do so until the water level falls below L, at which time power to the coil of the relay is interrupted. The relay is deenergized and the power to the pump is shut off until the water rises again to U and the cycle repeats.

    A diagram is attached which shows this latching circuit. Note that the contacts which switch the power to the pump motor are not included in the diagram.

    I know this doesn't really provide you with the exact information you requested, but I don't feel competent to try to tell you exactly how to wire this up. If I was working on my own well, I could do it, but it might involve some trial and error. For example, the coil of the relay may need a diode across it to protect the sensor contacts. In addition, I still am not convinced that the relay contacts have the current capacity to handle the pump power. I don't want to make things worse for you than they already are.

    Good luck. I am sorry I can't help more.
     
    Last edited: Feb 4, 2011
  9. Cabin_Crazy

    Thread Starter New Member

    Feb 1, 2011
    5
    1
    Tracecom, I have reviewed your comments about the current handling of the contacts and the solenoid. You've brought up some good points. I've ordered some new enclosed float switches (see attached) and now I need to source a better relay to handle the current as you've suggested. So, in essence, I've changed my schematic requirements again. The new float switches have THREE wires which I need to determine a latch-in circuit for.

    Thanks for your help.
     
  10. Cabin_Crazy

    Thread Starter New Member

    Feb 1, 2011
    5
    1
    When my regular electrician finally returned I had all my questions answered. I am posting the results of all my different scenarios for anyone searching in the future. This includes schematics for the JLD612 and JLD614 temperature controllers and my deep well pump wiring.
     
    Long_p1 likes this.
  11. williamj

    Active Member

    Sep 3, 2009
    180
    32
    Cabin_Crazy

    Just a suggestion...

    In the quote below it can assumed that you intend to place the lower sensor alongside of the pump. Don't. The sensor should be some distance "above" the pump to keep the pump from running dry and burning up again.

    williamj
     
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