Do-it-yourself water pump control device. A simple submersible pump control circuit

Pumping units used to normalize the water supply have a certain warranty period, but in order to extend it, it is advisable to use automatic control of the water pump. Such equipment is an installation that prevents the breakdown of the injection device when the water level in the source is insufficient.

If the pumping substation operates without an appropriate sensor, the risk of its failure increases, since they are not designed to work "dry". In conditions of fluid deficiency, equipment begins to deteriorate and burn out. If you install a water level sensor, you can prevent such troubles. This article is devoted to solving the issue of choosing a protective device, its principle of operation and features.

The selection of a relay to protect the pumping station from idle and maintain the optimal water level at home requires no less attention than. First of all, you should take into account the characteristics of your own well, as well as use indirect advice:

• installation should be convenient and accessible. Therefore, you should not purchase too massive installations. They must also correspond to the characteristics of the pump itself;
• ideal if your sensor has a simplified automatic adjustment. In other words, the device has the ability to independently disconnect from the network until the water in the well returns to the previous level;
• make sure that the protective relay is well waterproofed, since moisture on the housing will disable the mechanism if the liquid level rises;
• check with the seller how durable and reliable the pump part is. It does not hurt to find out how the frequent loss of the water level in the well affects the operation of the protection;
• the price should correspond to the optimal parameters, regardless of the manufacturer. The cost may vary due to the different pressure range and general technical characteristics.

Important! If you made the right choice and carried out the installation, the relay will be able to stop the device on its own without harm to the working mechanism of the pumping equipment.

The working mechanism of the sensor. How does the structure behave when turned on?

A typical idle switch for a pump is set to work in the pressure range from 1 to 8 bar, while it is guided by the level of the liquid. The internal mechanism of the sensor is a block with tuned springs that are responsible for the two-way pressure limits. They are regulated by special installed nuts. The pressure indicator is controlled by a membrane plate, with the help of which the spring is weakened at a minimum pressure and strained when it reaches a maximum value.

The pressure sensor spring is activated when the circuit contacts open and close. If the pressure drops, the contacts close, which is carried out by the protection sensor and the pump comes into working position. Otherwise, the pump turns off and does not operate until the pressure returns to the optimum levels.

To set up the correct operation of the sensor, you need a pump control circuit. In order to fine-tune, it is necessary to bring the pumping unit into working condition - this will increase the water pressure in the well. It is possible to regulate the operability of the installation with the help of specially removed screws under the cover, which protects the sensor automation.

You can set the trip limits of the protective device yourself. To do this, perform the following steps in sequence.

1. We fix the maximum and minimum pressure limits by the liquid level in the tank, at which the pump is in working condition. Be sure to take readings from the manometer.
2. We disconnect the pumping unit from electricity and disassemble the protective device.
3. Remove the housing cover and slightly loosen the nut holding the small spring.
4. Then we set the minimum pressure: we tighten or release the large spring also with the help of the fixing nut.
5. We open the valve in order to reduce the pressure in the pipeline system. At the same time, do not forget to control the operation of the pump.
6. We pay attention to the pressure gauge readings, if they are optimal for your case, leave the relay in this state, if not, we adjust further.

Attention! When setting up the idle speed control sensor, you must take into account the capabilities of the pump unit. For example, if its factory value with losses is about 3.5 bar, the relay should be set to 3 bar. Otherwise, there is a possibility of equipment overload.

A few words about the automatic control of the water pump

Devices based on the “automatic” scheme can be useful at home and on farms. It is especially important to have such equipment in systems where it is necessary to control the water level and its pressure.

Sensors based on an automatic control scheme are considered useful and do not require constant monitoring of the equipment of a well, well or other source of water supply. Also, such structures are often used multifunctionally.

Pay attention to the automatic control circuit of the pump, it is in no way connected with the common tank, from where water comes through the pump.

Often it is not enough to have only a pump for pumping out or replenishing water, it is also necessary to manage it, that is, turn it on and turn it on on time. Everything would be fine if you have such processes planned, and if not, then what to do? Let's say you have a cellar where water comes in... Or the reverse situation. There is a tank, which should always be full, ready for watering. During the day, the water is warmed up, and in the evening you water. So, you need to constantly monitor both, and this is all the time, worries, your work. But in our age, such tasks are already being solved once or twice, that is, it is possible to automate the process. As a result, automation will do everything for you, pump or pump out water, and you will only have to very rarely follow it. Check its performance. Well, my article will just be devoted to such a topic as the implementation of a scheme for pumping out or pumping water by level, then I will talk about this in more detail and in detail.

Scheme of control (shutdown) of the pump for pumping water by level

I'll start with the water pumping scheme, that is, when you are faced with the task of pumping water to a certain level, and then turning off the pump so that it does not idle. Take a look at the diagram below.

It is such a circuit diagram that is capable of pumping water to a predetermined level. Let's look at the principle of its work, what is here and why.

So, let's imagine that water replenishes our tank, it doesn't matter if it's your room, cellar or tank ... As a result, when the water reaches the upper reed switch SV1, voltage is applied to the coil of the control relay P1. Its contacts are closed, and a reed switch is connected in parallel through them. Thus the relay is self-caught. The power relay P2 is also turned on, which switches the contacts of the pump, that is, the pump is turned on for pumping out. Further, the water level begins to drop and reaches the reed switch SV2, in this case it closes and supplies a positive potential to the coil winding. As a result, there is a positive potential on the coil on both sides, the current does not flow, the magnetic field of the relay weakens - relay P1 turns off. When P1 is turned off, the power supply for relay P2 is also turned off, that is, the pump also stops pumping water. Depending on the power of the pump, you can choose a relay for the current you need.
I didn't say anything about the 200 ohm resistor. It is necessary so that during the switching on of the reed switch SV2 there is no short circuit with a minus through the relay contacts. It is best to choose a resistor such that it allows relay P1 to work confidently, but at the same time it has the highest possible potential. In my case it was 200 ohms. Another feature of the scheme is the use of reed switches. Their advantage when used is obvious, they do not come into contact with water, which means that the electrical circuit will not be affected by possible changes in currents and potentials in various life situations, whether it is salty or dirty water ... The circuit will always work stably and “without misfires”. No circuit configuration is required, everything works right away, with the right connection.

After 2 months...

Now about what was done a couple of months later, based on the requirement to reduce standby power consumption. That is, this is the second version of everything that I talked about above.
You understand that according to the diagram above, a 12-volt power supply will be constantly turned on, which, by the way, also consumes not free electricity! And based on this, it was decided to make a circuit for triggering a pump for pumping or filling water with a current in standby mode equal to 0 mA. In fact, it turned out to be easy to implement. Take a look at the diagram below.

Initially, in the circuit, all circuits are open, which means that it consumes our declared 0 mA, that is, nothing. When the upper reed switch closes, the voltage through the transformer and the diode bridge turns on relay P1. Thus, the relay switches power through its contacts and a 36 Ohm resistor to the power supply and again to itself, that is, it picks itself up. The pump turns on. Further, when the water level reaches the bottom and relay P2 is activated, it breaks the very self-catch circuit of relay P1, thus de-energizing the entire circuit and putting it into standby mode. The 36 ohm resistor is used to limit the current to the pump, at least a little, when the upper reed switch is turned on. Thus, reducing the induction current on the reed switch and extending its life. When the power supply is already powered through relay P1, after it is triggered, such resistance will easily provide voltage to hold the relay, that is, it will not be critical, and secondly, it will not heat up, since an insignificant current will flow through it. This is only the current from losses in the winding and the current to power the relay P1. Therefore, the requirements for the resistor are not critical, except to take it more powerfully!
It remains to be said that in any of these schemes, not only a reed switch, but simply end sensors can be used.

Well, now let's look at the reverse situation, when it is necessary to pump water into the tank and turn it off at a high level in it. That is, the pump turns on when the water level is low, and turns off when it is high.

"+" - ease of assembly and does not require adjustment. Does not consume current in standby mode!
"-" - The system has a limit sensor operating with high voltage, so it is better to take it out of the water

Scheme of control (shutdown) of the pump for loading water by level

If you cover our article all fluently and at once with your eyes, you will notice that we simply simply did not give the second scheme in the article, except for the one above.

In fact, this is a self-evident fact, because what is the difference between the pumping scheme and the pumping scheme, except that the reed switches are located one from the bottom of the second from the bottom. That is, if you rearrange the reed switches, or reconnect the contacts to them, then one circuit will turn into another.

I summarize that in order to convert the above scheme into a water pumping scheme, swap the reed switches. As a result, the pump will turn on from the lower sensor - reed switch SV1, and turn off at the upper level from reed switch SV2.

Implementation of the installation of reed switches as end sensors for pump operation depending on the water level

In addition to the electrical circuit, you will also need to make a design that ensures the closure of the reed switches, depending on the water level. For my part, I can offer you a couple of options that will satisfy such conditions. Take a look at them below.

In the first case, a design is implemented using a thread, a cable. In the second, a rigid construction, when the magnets are mounted on a rod floating on a float. It makes no sense to describe the elements of each of the structures; here, in principle, everything is very clear.

Connecting the pump according to the operation scheme depending on the water level in the tank - summing up

The most important thing is that this circuit is very simple, does not require adjustment, and almost anyone can repeat it, even without experience with electronics. Secondly, the circuit is very reliable and consumes minimal power in standby mode (1st option) or nothing at all (2nd option), since all its circuits are open. This means that consumption will be limited only by current losses in the power supply (option 1) or even less!

Video about the operation of level sensors for pumping and pumping water

The goal of this development is to design a simple but effective water pump control circuit to fill or empty a water tank. Pump control circuit built on an integrated circuit K561LE5, consisting of four logic elements.

The device uses two sensors: a short steel bar is the maximum water level sensor and a long one is the minimum level sensor. The container itself is metal and is connected to the minus of the circuit. If the container is not metal, then you can use an additional steel bar with a length equal to the depth of the container.

The circuit is designed so that when water comes into contact with a long sensor, as well as with a short sensor, the logic level, respectively, at pins 9 and 1.2 of the DD1 chip changes from high to low, causing changes in the operation of the pump.

When the water level is below both sensors, at pin 10 of the DD1 chip, a logical zero. With a gradual increase in the water level, even when the water is in contact with the long sensor, pin 10 will also be a logical zero. As soon as the water level rises to the short sensor, a logical unit will appear at pin 10, as a result of which transistor VT1 turns on the pump control relay, which in turn pumps water out of the tank.

Now, the water level is decreasing and the short probe will no longer be in contact with water, but pin 10 will still be a logic one, so the pump continues to run. But when the water level drops below the long sensor, a logic zero will appear at pin 10 and the pump will stop.

Switch S1 provides reverse action. When the resistor R3 is connected to pin 11 of the DD1. the pump will run when the tank is empty and stop when the tank is full, i.e. in this case the pump will be used to fill and not to empty the tank.

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It often happens that it is not enough to have only a pump for pumping out or replenishing water, it is also necessary to correct it, that is, turn it on and turn it on on time. Everything would be fine if you have such processes planned, and if not, then what to do? Let's say you have a cellar where water arrives ... Or the reverse situation. There is a tank, which should always be full, ready for watering. During the day, the water is warmed, and in the evening you water. So, you need to constantly monitor both, and this is all the time, worries, your work. But our age, such tasks are already being solved once or twice, that is, it is possible to automate the process. As a result, automation will do everything for you, pump or pump out water, and you will only rarely have to monitor it, check its performance. Well, our article will just be given to such a topic as the implementation of a scheme for pumping or pumping water, then we will talk about this in more detail and in detail.

Scheme of control (shutdown) of the pump for pumping water by degree

We'll start with a water pumping scheme, that is, when you are faced with the task of pumping water to a certain extent, and then turning off the pump so that it does not idle. Take a look at the diagram below.

Actually, such a circuit diagram is capable of pumping water to a predetermined degree. Let's look at the principle of its work, what is here and why. So, let's imagine that water replenishes our tank, it doesn't matter if it is your room, cellar or tank ... As a result, when water reaches the upper reed switch SV1, voltage is applied to the coil of the great relay P1. Its contacts are closed, and a reed switch is connected in parallel through them. In this manner, the relay is self-caught. The power relay P2 is also turned on, which switches the contacts of the pump, that is, the pump is turned on for pumping out. Further, the water level begins to drop and reaches the reed switch SV2, in this case it closes and supplies a positive potential to the coil winding. As a result, there is a positive potential on the coil on both sides, the current does not flow, the magnetic field of the relay weakens - relay P1 turns off. When P1 is turned off, the supply of tables for relay P2 is also turned off, that is, the pump also stops pumping water. In bondage to the power of the pump, you can pick up a relay for the current you need.
We didn't say anything about the 200 ohm resistor. It is necessary so that during the switching on of the SV2 reed switch there is no short circuit with a minus through the relay contacts. It is better to choose a resistor in total so that it allows relay P1 to work confidently, but at the same time it has the highest possible potential. In our case, it was 200 ohms. Another feature of the scheme is the use of reed switches. Their advantage in application is obvious, they do not come into contact with water, which means that the electrical circuit will not be affected by possible changes in currents and potentials in various life situations, whether it is salty or impure water ... The circuit will always work stably and “without misfires”.
Well, now let's analyze the reverse situation, when it is necessary to pump water into the tank on the contrary and turn it off when the level rises.

Scheme of control (shutdown) of the pump for loading water by degree

If you cover our article all fluently and at once with your eyes, you will notice that we simply simply did not give the second scheme in the article, except for the one that is taller. In fact, this is a self-evident fact, because what essentially distinguishes the pumping circuit from the pumping circuit, except perhaps by the fact that the reed switches are located one at the bottom of the second at the bottom. That is, if you rearrange the reed switches, or reconnect the contacts to them, then one circuit will turn into another. That is, we summarize that in order to convert the above scheme into a scheme for pumping water, change the reed switches in points. As a result, the pump will turn on from the lower sensor - reed switch SV1, and turn off at the upper level from reed switch SV2.

Implementation of the installation of reed switches as end sensors for actuating the pump in bondage from the water level

In addition to the electrical circuit, you will also need to make a design that ensures the closure of the reed switches, in bondage to the water level. For our part, we can offer you a couple of options that will satisfy such conditions. Take a look at them below.

In the first case, a design is implemented using a thread, a cable. In the second, a rigid construction, when the magnets are introduced on a rod floating on a float. To describe the elements of each of the structures of a special reason neti, here, in principle, and so everything is very clear.

Connecting the pump according to the triggering scheme in bondage from the water level in the tank - summing up

The most important thing is that these circuits are very simple, do not require adjustment and anyone can repeat it utilitarian, even without experience with electronics. Secondly, the circuit is very reliable and consumes minimal power in standby mode, since all its circuits are open. This means that consumption will be limited only by current losses in the power supply, no more.

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If for financial reasons or for some other reason you do not want to purchase a ready-made pump control device, then the "Master KIT NF250" kit will help you, which allows you to assemble a simple electronic device to maintain the required water level in the storage tank.

The principle of operation of the "smart assistant" is as follows. When the water level in the shower tank drops below a certain level "L", the pump turns on and starts pumping water into the tank. When the water level reaches the set level "H", the device switches off the pump (Fig. 1). The general view of the device is shown in Fig.2.

Rice. 1. The principle of operation of the device for controlling the country pump.

Rice. 2. General view of the device.

Rice. 3. Schematic electrical circuit.

Device Specifications
Supply voltage, V - 12
Current in rest mode, mA - 1
Current in relay operation mode, mA Switching power, W - 1300
PCB dimensions, mm - 61x41
The electrical circuit diagram is shown in Fig.3.

Operating principle

Water has electrical conductivity. While there is no water in the tank, transistors T1 and T2 are closed, a high voltage is present on the collector of transistor T1. This high voltage, flowing through the diode D1 to the base of the transistor TK, opens it and the transistor T4, which leads to the activation of the executive relay, to the power contacts of which the pump is connected.

The pump starts pumping water into the tank. The LED indicator turns on, indicating the operation of the pump. When the water level reaches the sensor "L", the transistor T1 opens, the voltage on its collector disappears. However, the pump continues to work, because the base of the transistor TK is energized through the resistor R8 and maintains the TK-T4 key in the open state.

When the water level reaches the "H" sensor, transistor T2 opens and a low level enters the base of transistor TK. The TZ-T4 key closes - the relay turns off. Only when the water level falls below level "L" again will the relay switch on again.
The list of elements is given in the table.

Rice. 4. The appearance of the printed circuit board from the side of the parts and from the side of the conductive tracks.

Design

Structurally, the device is made on a printed circuit board made of foil fiberglass with dimensions of 61x41 mm (Fig. 4). As sensors "L" and "H" you can use improvised materials, for example, copper plumbing half-inch nuts, firmly attached to insulated wires.

Turning on the device

Connect the wires of the sensors to the board and place them in the experimental tank of the same height as the used tank in such a way that the positions correspond to:
"COM" - at the bottom (if the container is iron, then you can connect this wire to the container body);
"L" - at the desired lower water level (pump activation level),
"H" - at the pump shutdown level.

Connect the device to a power source, observing the polarity. Do not connect mains voltage and pump yet. Turn on the power. The indicator LED should light up and "click" the relay, connecting the pump. Pour water into a container. When the water level reaches the "H" sensor, the relay should turn off. Pour out the water from the container. When the water level falls just below the "L" sensor, the relay should turn on.

Now you can finally mount the sensors on a real object and, being careful, connect 220 V and a pump to the contacts of the circuit.

Y. SADIKOV, Moscow