Automatic Switch-Off of Water Pump

Look at a standard pushbutton start/stop circuit for a motor. Replace the stop pushbutton with the normally closed contacts of your level switch.

L1----o (NO "start" pushbutton) o------------------------------A

L1----o (NC level switch) o----o (NO motor starter contact) o---A---o (motor starter coil) o----L2

Connect both L1's together, and both A's together; L1 and L2 are control power.

P1----o (NO motor starter contact) o----o (motor) o----P2; P1 and P2 are motor power (repeated for as many phases as the motor)

My scanner is on another computer, or I would do a sketch. Sorry about the kludgy attempt with typography.

I think OP can put a motor starter between controller and motor, So once motor is switched off by controller it will not restart even if controller try to do it so. He will have to reset starter manually.

Use a motor starter (or combo-starter depending on application requirements), a single float (at low level position) for auto off, a second single float (at high level position) for auto on, an HOA (Hand-Off-Auto) to disable the high level float, and a NO (normally open) E1PB (pushbutton) to take over the duty of the high level float manually when the HOA is in the "hand" position.

The high level float is not required based on your description but we usually install them anyway due to low cost and the possibility that the client may want fully automatic operation for different applications or maintenance.

Depending on your local, try checking with Square-D and GE. Both companies offer pre-wired pump panels to this configuration. In either case, both stock the parts to build a controller if you want to do it yourself.

Hi KJK,

yes.. thats the type I want.. I do not want the motor to be switched on automatically,... but it should switch off under the conditions where there is no water in the well and once the over head tank is full.

Here when I checked with a manufacturer of water level controller (V-Guard), the they said it is not feasible in their system..

Hi, Raj.

Use Somar's INTEGRA motor-regulators. They have a programmable feature that automatically switches off motors after a set time of low-load operation (for example, when sump pumps operate with their sumps empty of water).

These are perfect protection of vertical sump-pumps whose rotor is cooled by sump water. These pumps burn out if they're left running when there's no waster in their sumps, and INTEGRA units are often used to protect against precisely that.

http://www.somars.com/energy-saving-products/somar-technology.php

Cheers! DZ

Hi DZ

Is this available in India.. if yes, whats the cost?

rgrds

Hi RAJ,

If you cannot find a ready made system or something like Tornado's (Simple and easy), you can stil build your own:

The existing Floats (O/head and Feed tank) are supposed to be working as you said, driving the pump On / Off automatically.

Then, add a start p/button with a N.O. contact in series to all of these, at the beginning of your power supply circuit to the floats etc...

Then, if the motor is directly supplied, without a contactor, replace the motor with a contactor having the suitable coil voltage, and an extra contact N.O.

The extra N.O.contact should be wired in parallel to the start P/Button contact.

The contactor will drive the motor. When any condition(full tank or empty supply) causes the contactor to drop, you will need to restart manually.

You need this kind of Contactor (undirect control) scheme to add your required semi-auto control.

Hi, Raj.

I'd be surprised if it weren't available in India. Go to the Somar website and request info concerning who to get them from ...

http://www.somars.com/download-prospectus.php

Good luck! DZ

Hello rajkochi

There is a simple solution to managing most low yield wells. I would advise that the well be equipped with a submersible pump though. If the well runs dry, a centrifugal pump will require priming whereas the submersible will auto start.

Add a device called a pumptec to the submersible pump (works for single phase two or three wire) and there is another for three phase situations. The connection I indicated is for a QD-pumptec for retrofitting a system with three wire control, other configurations are available. The device monitors the amperage and when the well runs dry the amperage or load on the pump drops. The well pump shuts off within 4 seconds. A timer on the pumptec allows variable settings. For example, you could set it to come on every 30 minutes. The pump will rest and the well will recover for 30 minutes and then start to dump whatever water has recovered from the well to your reservoir. The pumptec will shut the pump off if the well runs dry and start another cycle-all automatically.

To control the fill of the reservoir use a reverse float switch similar to most sump pumps except it shuts everything down when reservoir is full. As the float drops it restarts the system automatically.

The reservoir switch will control the pumptec and the well pump so the system is all connected. I have installed many such systems and they work very well for a long time at minimum cost.

Kevin ... good one!

This Pumptec thing is exactly what Raj needs. Powerboss Integras are great for motor regulation and control, but they're overkill for simple submersible- or vertical-pump protection.

I'll recommend these Pumptecs to various customers of mine. Many of them are inthe mining sector, which has sumps all over the place both in mines and concentrators. Even better, submersible pumps burn out all the time because of control failures (level swicthes, etc.); this is a constant headache for mining firms.

Thanks for the info. Much appreciated, fellow Canadian!

And Raj ... go for what Kevin recommends or something similar. There must things like it available in India. Also, like Kevin says, make sure your pumps are either submersible, in which case they'll be in the sump/well, or vertical ones, in which case the motor will be at the surface or top of the sump and the impeller inside the sump/well with a shft linking the two.

Cheers! DZ

Why would you need automatic shut off and manual start ?

why not have switch that turns it off and on ?

Please explain

Peter

My system has been installed many times and is completely automatic. We sometimes install alarms on the reservoir supporting low yield wells to warn of impending problem. Otherwise it is fully hands off. A manual restart defeats the whole purpose and adds poor utilization of the water supply. These pumptec devices are very low cost and quite reliable in protecting the submersible pump. You could build your own but I think it would be more costly. In Ontario we would have an added cost of approval by the utility. The pumptec already is approved as CAS or UL.

Storage is always the best solution to low yield wells. We have designed subdivisions using wells with these systems so that neighbouring wells will not interfere with each other during peak usage.

http://www.google.co.uk/search?q=water+level+switch+circuit&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-GB:official&client=firefox-a

http://electroschematics.com/2153/water-level-indicator-sensor/

http://www.fluidswitch.com/

hi.

i am aditya, i hv made a 4- channel distribution control using real time clock with memory feedback. it has 4 channels all r set to different times and dates, once set , it runs for months, very easy to handle ,.

so, u want to make ur motor switch on and off for regular time interval, it really helps u out. real time clock is very easy to handle, it make motor to run for periods as once set,.

if any more query or information , please reply me.

thanx

aditya maurya