[JEG in Raleigh]

Newbie here, and first post. OK, here's the story: My water is supplied by a well. I have a water softener and 2 backwash filters on the system to treat the water. I did all the installation, so I'm knowledgeable about the system. Those filters and softeners do a good job of treating the water, but we also have sulfur smell problem with our water. To remedy that problem, I bought a hydrogen peroxide injection system to inject a metered amount of H2O2 into the water flow after the pressure tank. This oxidizes the sulfur and removes the smell. There is a 15 gallon tank that I will with a diluted hydrogen peroxide solution. There is a small diaphragm dosing pump that is attached to the top of the peroxide tank and it has a tube coming out of it that is connected to the house water piping and injects the peroxide solution into the water flow. The pump runs on 120 voltage. Then, I have a flow meter installed after the pressure tank and before the backwash filters. This flow meter has a reed switch that is part of it that sends very low voltage signals to the dosing pump when water is flowing through the flow meter....for example, when you turn on a faucet in the house. The dosing pump has a connector plugged into it that receives this signal, and there are electronics inside the pump that are supposed to trigger the pump to stroke 3 times per gallon of water flowing through the flow meter. This makes the pump a proportional pump that increases the number of strokes per minute depending on the volume of water flowing through the flow meter. So, for example, if you have one sink faucet on, it will pump 3 strokes every 15 seconds or so. But, if you have a couple of sinks running and the shower running, then it should pump 3 strokes maybe every 5 seconds, etc. The number of strokes that the dosing pump pumps per gallon of water was programmed by me, following the directions of the manufacturer, and the number of strokes can be programmed up or down.

My problem is that the pump loses the program and does not pump proportionally. Once you turn on the water....even just a bathroom sink faucet....or flush the toilet, the pump takes off and starts pumping non-stop, regardless of the volume of water running through the flow meter. So, I'm burning through 15 gallons of my peroxide solution every couple of weeks, where it should be lasting me a couple of months, based on our typical water usage. Now...the dosing pump also has a manual setting, and when you put it in the manual setting, you can set it so that it pumps 3 strokes, every 15 seconds, or some other time interval of your choosing. The only thing is, that when the pump is plugged into the wall receptacle, and you have set it in manual mode, it starts pumping that 3 strokes every 15 seconds, for as long as it is powered on, regardless of whether you are using water or not....it just starts pumping to that interval, and keeps pumping.

OK, that's the background. Now, one other thing....the pump is designed to be turned on and off repeatedly, without damaging the pump. So what I want to do is have the pump power up, in manual mode, only when water is flowing through the flow meter, and then power off when water is no longer flowing. I'll lose the proportional feature, where the pump strokes increase in frequency when more water if flowing through the flow meter, but that's a compromise I can live with. To implement this new strategy, I want to use a relay to turn on power to the pump (and the pump would be in manual mode) and have that relay activated by the reed switch that is in the flow meter.

This is where I need help from the forum members. I can do basic house wiring....receptacles, switches, run new circuits to the panel, etc., but I have no idea what kind of relay I need to use or how to hook it up to the power going to the dosing pump. The pump is plugged into a conventional GFCI receptacle.

QUESTION 1: Do I make up some kind of j-box that contains the relay and has a cord coming out of it with a male plug end on it to plug into the GFCI receptacle, and then have another short cord with a female cord end on it to receive the male plug from the pump so the pump is actuated by the relay?

QUESTION 2: When I was trying to troubleshoot the original problem, I took a volt meter and put it on the wires coming from the reed switch and it registered 0.001 volts when the switch fired. So I'm guessing the relay would need to have enough sensitivity to be triggered by that voltage, is that correct.

QUESTION 3: Any advice on the relay to use and how to wire it up would be greatly appreciated. If what I suggested as a setup in QUESTION 1 is a good idea, please let me know. If it's a bone-headed idea, please also let me know. I don't even know what the relay would look like, or how big it would be, so I'm clueless on how to set this up.

I've reprogrammed the pump dozens of times, and it works as it should for 20 minutes and then loses the program. I give up. It's too late to return it and it was $300-$400. I want to try this idea. Any help would be most appreciated. Thanks!

 

[ServiceCall]

Too much to read. Can you do a readers digest condensed version?

 

[RAL238]

Are you sure the flow meter puts out a voltage, rather than simply being a dry switch contact that opens and closes?

There are relays that are designed to control AC loads using a low voltage control signal. I don't know of one that will operate from a voltage of 0.001V, though. But it might be possible to use yet another relay that will work with the low voltage from the flow meter to operate something like a RIB relay from Functional Devices.

Do you have links to the manuals for the controller and flow meter that you can post? Knowing more about what it is and how it operates would make finding a solution easier.

 

[Nickd83]

More than likely that flow meter is a dry contact, easy way to test is take the wires from the switch, put your meter to resistance(ohms), one lead on each wire. Flow water, it should change, one way it will be OL, one will be 0.1 or so ohms (assuming digital meter). One we know which is which, we can go from there with some other suggestions.

Also, have you tried contacting the manufacturer? It seems like there is an issue with the memory chip for the system, it should be non-volatile, meaning once it's programmed it should stay programmed, regardless of power cycles. I couldn't imagine having to reprogram this every time there's a power failure.

 

[surferdude2]

You can do what you are proposing but not with the flow switch you now have. It's likely a propertioning device and not really a switch. If so, it changes resistance based on flow volume. You could measure that resistance by disconnecting it and checking it with flow off and one to see how it reacts resistance wise.

Anyway, here's a rough and dirty way to do the job:

You will need the following components:

normally open (NO) flow switch (rated 75 mA or above)
relay in a box model RIBU1C
120 - 24 vac box mount transformer
Two 4X4 electrical j-boxes with lids to enclose all line voltage connections.
misc wire nuts and/or crimp connectors, line cord with plug, random length of line cord, five 2-screw cord connectors,

Wire that all up so the new flow switch controls the low voltage transformer connection to the low voltage relay coil wires (series loop). Then interrupt the present pumps power from its present source by connecting the normally open contacts of the new relay in series with the hot leg now serving the pump. Nut off all unused relay wires safely from shorting.

Keep all low voltage and line voltage connections separate and apart. Exit the relay low voltage coil leads immediately out of the junction box the relay and transformer are mounted on and make all low voltage connection as open wiring. Also enclose the line cord interrupt junction to the pump in a j-box.

Now you should be able to leave the system in manual mode and it will only run the pump when water is flowing.

This seems like a kludge but you asked for it so there it is. You can use a different relay and transformer if you have something suitable.

 

[JEG in Raleigh]

Thanks everyone. RAL238 and Nickd83, I guess it isn't putting out voltage. I looked at the spec sheet on the flow meter and it gives no technical information about the reed switch, but it does mention "pulse output" coming from the meter, so now I'm thinking it is what you're describing. And after reading Surferdude2's description of what would be needed to do what I want to do, he cured me of that idea and I guess I ought to first look for a new pump from a different manufacturer that will work and be reliable

 

[rdy2go]

Thanks everyone. RAL238 and Nickd83, I guess it isn't putting out voltage. I looked at the spec sheet on the flow meter and it gives no technical information about the reed switch, but it does mention "pulse output" coming from the meter, so now I'm thinking it is what you're describing. And after reading Surferdude2's description of what would be needed to do what I want to do, he cured me of that idea and I guess I ought to first look for a new pump from a different manufacturer that will work and be reliable

Do you have any friends that are into micro computers as hobby? It sounds like an easy project for something like ARDUINO, ESP32 or Raspberry PI.

 

[JEG in Raleigh]

No, I don't. The pump does work in what they call manual mode. In that mode, you can set a time interval for the pump to pump 1 time, and that function is working properly. Right now, when the thing takes off and starts pumping, it is pumping 100 times per minute. So, in manual mode, I could set it to pump...say....once every 10 seconds, and as long as it has power, it will keep pumping at that interval. I now think my goal when I started this thread, of using a relay activated by the reed switch on the flow meter as a workaround to the defective pump that would still achieve proportional dosing, is a waste of time, based on points that others have brought up. I think I'm going to try using a flow switch to turn on the pump when water is flowing and then just jigger around with the pumping interval in manual mode until I get the right amount of peroxide injected to remove the sulfur smell, and if that doesn't work, I'll look for a new pump. Thanks for your help.