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Participant

Join Date: Sep 2006
Posts: 3

Automatic Water Pump Switch

09/16/2006 5:28 PM

Here is my current setup:

I have a six foot barrel with a six foot long pole sticking up from thecenter of the barrel. Two buoys areattached by strings to a switch located on the top of the six foot barrel. Onebuoy hangs one foot from the bottom of the barrel and the other buoy is rightbelow the top of the barrel.

When each buoy is floating, both switches are in the on position and thepump pumps.

The pump stops when either of the buoys is no longer hanging.

The problem is that the water is always around the six foot mark. WhatI would like is for the pump to turn on at the six foot mark and then off againat the one foot mark.

Are there any suggestions how this can be arranged with the setup I have nowwith a few modifications?

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#1

Re: Automatic Water Pump Switch

09/16/2006 8:52 PM

Your explanation seems to contain some errors.

In any event, the system seems to pump as soon as the water drops below 6 feet = it stays at 6 feet.

This means you have a constant head of water in the barrel and a low duty cycle for the pump = good.

If you want it to stop at 6 feet and wait for the water to drop to one foot before it starts to pump again, you would need some type of sliding linkage in the form of a loop to introduce that 5 foot variation.

If I was you, I would leave it as it is.

Why do you want the wide range of 1 foot to 6 feet?

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Participant

Join Date: Sep 2006
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#2
In reply to #1

Re: Automatic Water Pump Switch

09/16/2006 9:38 PM

My goal is to have no water in the barrel once the pump begins to pump.

If things were the way I wanted, the pump would turn on when the water reached the 6 foot mark and turn off when the barrel was empty, turn on again once the water reached the 6 foot mark and continue on this pattern.

I am working with two buoys attaced to two switches. The switches are in series. Each switch is activated when its respective buoy floats.


Does that clear things up?

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#3
In reply to #2

Re: Automatic Water Pump Switch

09/16/2006 9:50 PM

Yes, it looked as if you were pumping water into the barrel to keep it full and as soon as it dropped to one foot you filled it again.

Now you want the pump emptying the barrel as soon as it gets 6 feet deep and going off as soon as it drops to 1 foot, much like a standard sump pump.

Try these:

http://www.discovercircuits.com/W/water-level.htm

https://hometips.com/cs-protected/guides/sumps.html

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Member

Join Date: Sep 2006
Location: Reading Pa.
Posts: 5
#4
In reply to #2

Re: Automatic Water Pump Switch

09/16/2006 10:14 PM

The problem is in the configuration of your floats.

1- Do not series the floats. By putting the floats in series what happens is the float that turns the pump on also turns it back off. The lower float does nothing once the water level is above it.

2- There are two ways to achieve your goal that are inexpensive.

A-Install an inexpensive timer that the upper float will activate to run the pump for the required time to empty the barrel with lower float being used to stop the pump at the required level.

B- Install a latching relay that is activated by the upper float and deactivated by the lower float.

I am not sure what type of pump you are using,(ie Self priming or primed pump) in any case i recommend that you maintain a water level slightly above the pump so set your lower float at a level to maintain a slight head on the pump.

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Participant

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#5

Re: Automatic Water Pump Switch

09/17/2006 1:53 PM

Thanks for all the help!

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Guru

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#6
In reply to #5

Re: Automatic Water Pump Switch

09/17/2006 11:31 PM

The relay idea is a good one and simple. Use a double pole double throw relay. Wire the lower switch to turn on the pump through the normally open contacts of one pole. Use the upper switch to turn on the relay coil. Use the other set of contacts to control the pump. The upper switch will turn on the relay that will turn on the pump and latch on due to the lower switch until the lower switch drops out and disables the relay.

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Power-User

Join Date: Apr 2006
Location: Calgary, Alberta
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#7

Re: Automatic Water Pump Switch

09/18/2006 1:54 AM

I used to make electronics that did that sort of thing. Usually more reliable than mechanical things like floats, and not overly pricey. We did it for very expensive industrial carpet cleaners which can't have foam in their vacuums so floats - which are usually heavier than bubbles - didn't do it. Touchy electronics does it pretty well.

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Anonymous Poster
#8

Re: Automatic Water Pump Switch

09/18/2006 10:32 AM

Use an Omron floatless level switch - it has 3 probes which you set to the heights you want, and it operates exactly as you require.

It plugs into a relay base, runs on your control voltage and can switch a contactor for your pump.

Regards,

Simon.

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Member

Join Date: Dec 2005
Posts: 5
#9

Re: Automatic Water Pump Switch

09/18/2006 10:40 AM

Sounds like what your looking for is a pump latch/unlatch circuit.

You probably will need a simple relay and some rewiring. Wire the float circuit in series with the high level switch being N/O and the low level switch N/C. When the tank level goes high the high switch closes and the relay is wired so that its coil is now latched into the pwer circuit and is being held in. When the N/C low level switch is tripped it will unlatch the circuit.

This is the same type of circuit used for a simple motor start and stop circuit.

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Anonymous Poster
#10

Re: Automatic Water Pump Switch

09/18/2006 1:35 PM

I used to maintain sewage pumping stations, our system was controlled by NoFlote switches, these were long rods, set at different heights to start up on full and stop at the desired level, NOFLOTE I believe is the trade name for the system manufacturer

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Participant

Join Date: Jul 2006
Posts: 2
#11

Re: Automatic Water Pump Switch

09/18/2006 5:05 PM

It sounds like you've made your application more complicated then what it needs to be. Here at Remote Control Technology, we've had provided wireless systems for several pump/tank applications.

Firstly, instead of buoys, float or pressure switches are commonly installed in the tank to get more precision with the levels in the tank, which then can be inserted into one of the dry contact closures of the transmitter. This would definitely relieve the concern with the water always being at the six foot mark. Two float switches would be preferrable for you application. One at the top where the 6 FT mark is and one at the base of the tank where the 1' FT mark is. That way the transmitter would send a signal to the pump to activate or deactivate at either of the float switches.

What's nice about wireless systems is that it completely automates the whole precess for you without things floating around in the tank and the best part is - it's instantaneous.

Check out our website ... Remote Control Technology

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Active Contributor

Join Date: Dec 2005
Posts: 18
#12

Re: Automatic Water Pump Switch

09/18/2006 8:53 PM

The two buoys should be on a single string, one near the top of the barrel, one near the bottom. The switch should turn the pump on when both buoys are floating, leave it on while only one buoy (the lower buoy) is floating then turn the pump off when both buoys are hanging, (i.e. more weight) This requires a switch that operates at a set down load, between both weights. I have several of these installations, and they work O.K. A Chinese company makes the system I use.

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