Submersible pump control circuit with level sensor. Homemade pump control device. LED indication scheme

A do-it-yourself device on a single transistor can be made by almost anyone who wants it and makes little effort to purchase very inexpensive and not numerous components and solder them into a circuit. It is used for automatic replenishment of water in supply tanks at home, in the country and wherever there is water, without restrictions. And there are many such places. First, consider the scheme of this device. It just doesn't get easier.

Water level control in automatic mode using the simplest electronic circuit water level control.
The whole water level control circuit consists of a few simple parts and if assembled without errors from good parts, it does not need to be adjusted and will immediately work as planned. I have had a similar scheme without failures for almost three years, and I am very pleased with it.

Automatic water level control scheme

Parts list

• The transistor can apply any of these: KT815A or B. TIP29A. TIP61A. BD139. BD167. BD815.
• GK1 - lower level reed switch.
• GK2 - upper level reed switch.
• GK3 - emergency level reed switch.
• D1 - any red LED.
• R1 - resistor 3Kom 0.25 watts.
• R2 is a 300 ohm 0.125 watt resistor.
• K1 - any 12 volt relay with two pairs of normally open contacts.
• K2 - any 12 volt relay with one pair of normally open contacts.
• As signal sources for replenishing water in the tank, I used reed float contacts. The scheme is designated GK1, GK2 and GK3. Made in China but very good quality. I can't say a single bad word. In the tank where they stand, I have ozone treatment of water and over the years of work on them there has not been the slightest damage. Ozone is an extremely aggressive chemical element and it dissolves many plastics completely without residue.

Now consider the operation of the circuit in automatic mode.
When power is applied to the circuit, the GK1 low level float is activated and power is supplied to the base of the transistor through its contact and resistors R1 and R2. The transistor opens and thereby supplies power to the coil of relay K1. The relay turns on and with its contact K1.1 blocks GK1 (lower level), and with contact K1.2 it supplies power to the coil of relay K2, which is an executive one and turns on the actuator with its contact K2.1. The actuator may be a water pump or an electric valve that supplies water to the tank.
Water is replenished and when it exceeds the lower level, GK1 will turn off, thereby preparing the next cycle of work. Having reached the upper level, the water will raise the float and turn on the GK2 (upper level), thereby closing the chain through R1, K1.1, GK2. The power to the base of the transistor will be interrupted, and it will close, turning off relay K1, which will open K1.1 with its contacts and turn off relay K2. The relay, in turn, will turn off the actuator. The scheme is prepared for a new cycle of work. GK3 is an emergency level float and serves as insurance if the upper level float suddenly does not work. Diode D1 is an indicator of the operation of the device in the water filling mode.
And now let's start making this very useful device.

We place the details on the board.

We place all the details on the breadboard so as not to make a printed one. When placing parts, you need to consider to solder as few jumpers as possible. It is necessary to use the conductors of the elements themselves for installation as much as possible.

Final look. The imperfection of our rural housing and communal services - namely, the problem with water supply - prompted the manufacture of the pump control unit. Either the pipes break through, or the pump at the pumping station burns out, and so on. As a result, a well was drilled near the house and a vibration pump of the "Kid" type was placed in it, and a 250-liter stainless steel tank and a compressor station were installed in the basement of the house, maintaining pressure in the house's water supply. But there was a problem - to maintain the water level in the tank. I did not find anything I liked on the Internet and began to make the device according to my needs. I began to look for level sensors and found these (see photo of the sensor).

As an option for controlling the pump in the well, I decided to come up with something on the controller, and at the same time master it a little, since I needed multi-mode. The ATtiy2313 microcontroller was taken as a basis and such a circuit was developed (for better quality, see the attachment in splan7 format). Pump control scheme:

It was written in assembler, you can download it here in the archive. This scheme allows you to control the pump in 3 modes (selected by the "Mode" button):
1) "Bath" mode - turning on the pump from the "On / Off" button - this is in order to pour water directly from the well into the bath, well, or wash the car.
2) "Summer" mode - maintaining the water level in the tank using level sensors (when the level is reached, the sensor contacts close)
3) "Winter" mode - adding water (on/off button) to the tank up to the "Max" level when the level is below "Min". The mode was introduced so that during winter frosts the water in the hose freezes and in order to turn on the pump in the well, the hose must first be thawed with hot water.

I screwed the display for reasons of convenience, at first I wanted LEDs, but you can’t explain to your family what kind of light it means, there won’t be enough memory). The first line of the display shows information with the name of the mode, the second - such information as "Pump running", "Pump off" and "Minimum level" for winter regime. As a result, the assembled pump control device looks like this:

For convenience, I added the display backlight to turn on for about 8 seconds when any button is pressed. 12 volt power supply and repeater relays are not particularly needed here. I installed them because of the large length of cables (almost 15 meters) to the level sensors. Scheme author: skateman.

Discuss the article PUMP CONTROL

Reliable water supply is an integral part of a residential building, public building, production premises. But the issue of water disposal is no less important. In order to maintain an appropriate level of comfort at the facility and increase the durability of building structures, it is necessary to perform emergency pumping of water, as well as ensure the operability of the drainage and sewerage system in any conditions, preventing flooding and overflows. It is for this that the “fighters of the invisible front” work - fecal and drainage pumps, which independently work somewhere in a personal plot or in the bowels utility rooms. Automation for drainage pump makes the equipment truly practical and as efficient as possible.

The drainage pump is also called the "pump for dirty water”, as it can pump liquids containing a large amount of solid particles. In surface or submersible versions, this equipment is indispensable for pumping water from tanks that need to maintain a “level”: pits, pits, wells, storage tanks, collectors, large sewers, drain pits, etc.

Cascade of two pumps with float switches and control panel

Such devices will help protect vulnerable premises that are periodically flooded (basements, cellars, basement floors). Also, drainage pumps are used for maintenance (clean, remove excess water) artificial reservoirs with a soil bottom, they allow you to easily pump water for irrigation of farmland from natural sources - rivers and lakes.

Important! The ability to pump and transport liquids with mechanical inclusions does not mean at all that the drainage pump will not pump clean water. Often it is used to fill storage tanks, for example, when implementing a two-stage autonomous water supply system for a cottage.

Basic functions of automation

The main task of automation for drainage pumps is to turn the pump on and off when the specified conditions are reached, which makes it possible not only to forcibly drain and fill containers, but to maintain the required safe level of liquid without the participation of the homeowner.

Pumps are expensive devices. They "do not like" to work without water, which, being a pumped working medium, also plays an important role in lubricating some moving parts and cooling equipment. Dry running for a drainage pump is just as harmful as for any other device. Practice shows that it is impossible to be one hundred percent sure that this will not happen, even if the level in the source / reservoir is actively replenished. To avoid such situations allows automation, which at the right time turns off the power.

Drainage pump control station configuration option

Automation for a drainage pump is not just a switch. It should be considered as a complex multi-component device, the so-called "control panel", which, among other things, protects power equipment from:

• short circuit;
• voltage drop (from high and too low);
• leakage current (including human from electric shock);
• phase wire breaks and phase imbalance (for 380 volt devices);
• increasing the current strength (when the impellers are jammed);
• burning / sticking of contacts and terminals.

Ready-made remotes are available for sale, to which you only need to connect the necessary sensors and program them. If you have experience, you can assemble a functional control unit on the DIN rail of a separate shield yourself.

Important! Devices that control the operation of drainage pumps allow you to turn on / off other electrically dependent devices, such as heating elements, as well as using an audible buzzer or lamp to signal the status of the equipment and emergency situations.

How to automate the operation of a drainage pump

Drainage pumping equipment is always controlled by a change in the liquid level. There are several options for devices, but they all function by applying or disconnecting power (the circuit breaks or closes). Consider the most common solutions for drainage devices.

Ways to use float switches

A universal device that allows you to control pumps when it is necessary to pump out liquid or fill tanks. The float switch is a small sealed plastic box with a permanently connected three- or four-wire cable up to 10 meters long. It is this type of automation that simple household pumps, but the "float" can be bought separately.

The float switch is installed by immersion in the pumped liquid, it is attached to the tank wall or fixed on the pump power cable. To more accurately set the operating level range, a sliding weight is put on and fixed on the switch wire. By changing the length of the cable between the switch and the load, the optimal moments of the float operation are set.

In fact, the float switch is both a level sensor and a switching device. It works very simply. Inside the body with positive buoyancy, a metal ball moves freely through a special channel. When the float is raised/lowered at an angle of about 45 degrees, the ball goes to its extreme position and hits the on/off microswitch key, which, in turn, powers the circuit or breaks it.

Important! A drain pump automation with a microswitch in the float is an inexpensive solution, but it cannot provide high level control accuracy. In addition, the float switch does not allow the tanks to be completely drained. It also has problems with sticking contacts, which, however, is solved by using an auxiliary contactor.

Diagram of an automation device with three conductometric sensors

Conductometric level sensors

The principle of operation of such a control system is based on the electrical conductivity of the pumped liquids. Stainless steel electrodes are immersed in water. One of them, the control one, must always be in the water, while the others, the signal ones, are mounted at their levels. Between them, small currents are constantly transmitted through the working medium. If the water reaches the lower signal sensor, then a layer of air (which does not conduct electricity) appears between it and the control electrode, which immediately catches the control unit. And when the water rises to the upper sensor, the air, on the contrary, is displaced by the liquid, and the signal circuit is closed.

Important! The metal wall of the tank or a grounded pump housing can be used as a reference electrode.

If the floats can work both with a remote control and independently, then such automation is necessarily equipped with a remote control unit. It is to him that signals are received about the state of low-current circuits inside the tank, and then the controller gives a command to operate a switching device (for example, a magnetic starter) to turn the pump on / off. By the way, multi-electrode sensors can control several pumps that operate simultaneously or in turn, including those installed in different tanks.

Conductivity probes with multiple electrodes can be used in the system (to monitor a large number of levels), but configurations where only one electrode is functional are also possible. This variability allows you to assemble automation for a drainage pump with your own hands, which will be most effective for specific conditions. In any case, conductometric control devices are more reliable and much more accurate than control systems with float switches.

Video: pump automation

An important component for a comfortable pastime in country house is the availability of autonomous water supply. However, it is not always possible to connect to centralized water supply networks. In this case, you will have to drill a well or dig a well on the site. But this is not enough to fully provide the house with water. After all, you are not going to carry water in buckets. To create a fully automatic water supply, you will need pump equipment and additional automation, as well as a specific pump control scheme. For smooth operation of the pump, a control system is used, which can be assembled according to different schemes. It is them that we will consider in our article.

So that the water supply system country house was automatic and worked without your intervention, you need an automatic machine (automation system) that will maintain a certain pressure in the system and control the start and stop of pumping equipment.

To make pump control simple and reliable, in addition to standard general-purpose equipment (contactors, magnetic starters, switches and intermediate relays), special monitoring and control devices are used. These include the following products:

• jet relays;
• pressure and liquid level control sensors;
• electrode relays;
• capacitive sensors;
• manometers;
• float level sensors.

Pump equipment control options

The following types of devices are used to control a submersible pump:

• control panel, consisting of a block of necessary mechanisms;
• press control;
• automatic control that maintains a certain pressure in the water supply system.

The control panel is a fairly simple unit that allows you to protect the pump product from power surges and short circuits. Automatic operation mode can be obtained by connecting the control unit to a pressure and liquid level switch. In some cases, the control panel is attached to the float sensor. The price of such a control unit is low, but its effectiveness without the use of pump protection against dry operation and a pressure switch is in doubt.

Tip: for self-assembly it is better to use a block with a built-in system.

The control unit in the form of a press control has a built-in passive protection against dry running, as well as equipment for automated operation of the pump. To control the system, it is necessary to control a number of parameters, namely fluid pressure and flow rate. For example, if the water flow exceeds 50 liters per minute, then the pumping equipment under the control of the press control works without stopping. The machine operates and turns off the pump if the water flow decreases and the pressure in the system rises. If the fluid flow is less than 50 liters per minute, then the pump product starts when the pressure in the system drops to 1.5 bar. Such operation of the machine is especially important during sudden pressure surges, when it is necessary to reduce the number of starts and stops of the pump at a minimum flow rate.

An automatic control unit that allows you to maintain a constant pressure in the system must be used where any pressure surges are highly undesirable.

Attention: if the pressure indicators are constantly overestimated, then the energy consumption will increase, and the efficiency of the pump, on the contrary, will decrease.

Control cabinet

The most advanced machine for controlling the operation of pumping equipment is the control cabinet. All the necessary components and safety blocks for controlling a submersible pump are built into this device.

With the help of such a cabinet, you can solve many problems:

1. The equipment provides safe smooth start of the engine.
2. The operation of the frequency converter is being adjusted.
3. The device monitors the operational parameters of the autonomous water supply system, namely pressure, fluid temperature, water level in the well.
4. The machine equalizes the characteristics of the current supplied to the motor terminals, and also regulates the speed of the shaft of the pumping equipment.

There are also control cabinets that can serve multiple pumps. These products can solve even more problems:

1. They will control the frequency of operation of the pumps, which will increase the service life of the units, because thanks to the control unit, uniform wear of the mechanical parts can be ensured.
2. Special relays will monitor the continuous operation of pumping products. If one unit fails, the work will be shifted to the second product.
3. Also, the automation system can independently monitor the health of pumping equipment. During prolonged inactivity of the pumps, silting will be prevented.

The following components and elements are included in the standard package of the control cabinet:

• Case in the form of a steel box with doors.
• The front panel is made on the basis of the housing cover. It has built in start and stop buttons. The panel is equipped with indicators of the operation of the pump and sensors, as well as a relay for selecting automatic and manual modes of operation.
• Near the entrance to the equipment compartment of the cabinet, a phase control device is installed, which consists of 3 sensors. This block monitors the load by phase.
• The contactor is a product for supplying electric current to the pump terminals and disconnect the unit from the mains.
• Safety relay for short circuit protection. In the event of a short circuit, the fuse will be damaged, and not the winding of the pump motor or the components and parts of the cabinet.
• To control the operation of the unit, there is a control unit in the cabinet. There are sensors for overflow, start and stop of the pump. In this case, the terminals of these sensors are brought into the well or hydraulic tank.
• To control the rotation of the motor shaft, a frequency converter is used. It allows you to smoothly reset and increase the engine speed when starting and stopping pumping equipment.
• Temperature and pressure sensors are attached to the contactor and prevent the pump from starting under unsuitable conditions.

The simplest control scheme

The use of a simple scheme is justified for arranging water supply for a small country house. In this case, it is better to place the water collection tank on a slight elevation. Water will be supplied from the storage tank through a pipeline system to different places. personal plot and into the house.

Tip: as a storage container, you can use metal, plastic or wooden barrel or tank.

most a simple circuit control of pumping equipment is easy to implement independently, since it consists of a small number of elements. The main advantage of such a scheme is reliability and ease of installation.

The principle of operation of this control scheme is as follows:

1. To turn on and off the pumping equipment, a contact relay (K 1.1) of a normally closed type is used.
2. The scheme implies two modes of operation - the rise of water from the well and drainage. The choice of this or that mode is carried out by means of the switch (S2).
3. Relays F 1 and 2 are used to control the water level in the storage tank.
4. When the water in the tank drops below the level of the F1 sensor, the power is turned on through the switch S. In this case, the relay coil will be de-energized. The pumping equipment is started when the contacts on the K1.1 relay are closed.
5. After the liquid level rises to the sensor F1, the transistor VT1 will open and the relay K1 will turn on. In this case, the contacts of the normally closed type on relay K1.1 will open and the pumping equipment will turn off.

This control system uses a low-power transformer, which can be taken in a rotary receiver. When assembling the system, it is important that a voltage of at least 24 V is applied to capacitor C1. If you do not have KD 212 A diodes, then instead of them you can use any diodes with a rectified current within 1 A, while the reverse voltage should be more than 100 V.

wiring diagram pumping stations consists of general-purpose electric devices and specialized devices used in automatic control and protection circuits. In the electrical circuits of pumping stations, magnetic starters and automata, contactors and pump motors, alarm devices, control buttons, surge protection devices, and other equipment are widely used.

Specialized devices that help to implement the automatic control system of a pumping station include:

1. Pressure switch and liquid level control (float switch);
2. Pressure gauges and sensors;
3. Relays controlling the filling of centrifugal pumps.

The simplest electrical circuit for controlling a pumping unit.

Fig.1 Scheme of control of electrical units of the pumping station.

The simplest control scheme for a pumping unit can provide for two modes of operation of electric pumps:

1. Auto mode;
2. Manual control.

The current control mode is selected by the KU key.

Manual control:

1. The KU switch selects the manual mode.
2. To start the pumping unit, close the SBC power button and apply voltage to the KM magnetic starter.
3. The magnetic starter turns on and through the contacts KM1 becomes self-holding.
4. The power contacts of the starter supply voltage to the electric motor, the pump unit starts to work.
5. The pump is turned off with the SBT button.
The operator controls the operation of the equipment manually.

Automatic control

1. The KU switch is set to the automatic control position, the SB contact is closed and shunts the self-holding circuit.
2. Contact KK of the float switch is open when the liquid level in the tank is low. The pump is not working.
3. If the liquid level reaches a certain level, the float switch contact closes, the magnetic starter turns on, the pump starts pumping liquid from the tank.
4. When the liquid level in the tank decreases, the KK contacts open, the pump stops.

Motor protection

To protect electric motors against overload and short circuit currents, a QF circuit breaker with a combined release is used. Protection of the electric motor against voltage failure (zero protection) is carried out by a magnetic starter coil.
Control circuit for two hydraulic units of a pumping station.

Fig.2 Scheme of automatic control of two pumps.

The control scheme for two pumping units of a pumping station allows organizing automatic control of a pumping station without the participation of on-duty personnel. The electrical circuit of the pumping station includes 2 hydraulic pumps. One pump is operating normally. The second pump is on standby and is automatically switched on if the first one fails to cope with the load or fails. Which of the pumps is currently operating in the operating mode, and which is the standby one, is determined by the software pumping mode switch:

1. the first position of the switch - in the operating mode pump 1;
2. second position - pump 2 is in operating mode.

The scheme allows you to automatically control the electric motors of hydraulic units with permanently open outlet plugs. To determine the water level in the tank, the circuit uses a four-level electronic level sensor DU. Its contacts E1, E2, E3, E4 give control commands to start and turn off the engines of the water supply system.
Consider the operation of the circuit in automatic mode, with a working pump 1 with an engine M1. Software switch in 1 position. Contacts 1, 3 of the cut-off switch are closed, but relays RU1, RU2 do not work, since their circuit is open by contacts E2, E3 of the remote control sensor. If the liquid level rises to the level of sensor E2, the relay coil circuit RU1 closes. The relay is activated. Its contact RU1 closes, which supplies voltage to the coil of the magnetic starter. The magnetic starter with its contacts KM1.1 supplies power to the pump motor M1. The electric pump H1 starts and starts pumping.

In normal mode, the water level in the tank drops, the E2 contact circuit breaks, but the engine continues to run. It will turn off only when the water level drops below contact E1. This is done in order to avoid frequent on-off cycles of the engine with a slight fluctuation in the liquid level near the level of contact E2.
If the performance of the pump H1 is not enough or it is out of order, the liquid level will rise and close the contacts of the sensor E3, which will supply power to the relay coil circuit RU2. As a result, voltage will be applied to the magnetic starter PM2, the contacts of which will ensure the start of the electric motor M2 of the backup unit. The backup pump will turn off when the level drops below contact E1.

If the liquid level for any reason reaches the maximum allowable level, contact E4 closes. This will activate the alarm relay PA, which will notify personnel of the abnormal condition. Voltage control in the circuit is carried out using the RKN relay. Signaling circuits are powered by guaranteed power buses. The HL lamp indicates the presence of voltage in the pump control circuits. If necessary, you can transfer the pumps to manual control and control the processes of switching on and off manually.

Pump station valve control scheme

Consider the scheme of a pump valve, which is controlled through a gearbox by a small-sized asynchronous electric motor. When the voltage is applied to the circuit, the green lamp starts to glow halfway. It signals the closed position of the plug. The pumping unit is started by the level switch RU. One of the contacts of the switchgear gives a command to start the electric motor M1 of the pumping unit, and the second closes the circuit of the relay coil RP1, management work plug motor M2.

After starting the pump and increasing the pressure in the plumbing system to a normal level, the contact of the pressure switch RD is closed, connected in series with the contact switchgear in the RP1 coil circuit. Relay RP1 pulls up, closes the normally open contact and energizes the valve opening contactor KO. The contactor starts the M2 motor to open the valve. The valve opening process is controlled by the VK2 limit switch, as well as by a bright red lamp. After the valve is fully opened, the VK2 contacts will open, the KO will turn off, the valve control motor will stop. The red lamp will burn half-heartedly, and the green lamp will go out completely. The valve closing scheme works similarly. For emergency shutdown of the control circuit, the VKA emergency switch is used. When the switch is activated, both signal lamps go out.