The operation of pumps is controlled using various devices, and one of the most common is a water level float switch. It can simultaneously perform the task of a water level sensor and be an actuator for controlling the pump. Floats for the pump are placed in containers.
One tank can accommodate several such switches, and they can solve different problems:
- Monitor the operation of the main pump.
- Serve as an overflow sensor.
- Ensure the operation of the auxiliary pump.
- Serve as an emergency level sensor.
With the help of such devices, the pumping apparatus is protected from the “dry running” mode. When filling different tanks, this element protects them from overflowing. Float switches for pumps come in light and heavy sizes. The former are more often used in drainage and water supply systems; the second - in drainage, rain and fecal wastewater. In stores, devices are sold with a cable length of 2, 3, 5, 10 m.
Float Connection Diagram
Plumbers recommend thoroughly rinsing the float with a hose at least once a month to prevent it from sticking to the pressure pipe or pump walls during daily operation.
In such a situation, installation is performed using a special rod. It is worth noting that the ability to provide reliable protection for pumping systems during dry-running operation is not the only positive quality of such devices.
The tilt at which the ball moves from one position to another is most often 70 degrees, but you should check this when purchasing the device. Water level sensor in the container (tank) // Automatic filling of the container // In addition to this, a considerable amount of electricity is saved, since the float switch allows you to use the pump only when necessary. Light elements attract customers with a low price, but can only work in clean water intended for drinking and domestic needs. Due to the lack of pores on plastic cases, dirt appears on them.
They should be located on the sides of the body inside, so that the ball, falling between them, makes contact.
If the difference is more than a meter, two separate sensors are used, installed at the required heights. This type of sensor is most effective when working with bulk solids.
The voltage level is usually V.
Tackle for summer fishing rod. Sliding float and weight. My fishing.
Connecting and repairing a float for a pump
The fecal pumping equipment is switched on when the main control device is raised. As the amount of water in the tank decreases, the float will begin to fall, but until it takes the lower position and closes the NU contact, the pump will not turn on. Our response: Hello.
Inside the insulated cavity of the cable entry there is a polymer resin that protects against water ingress. Where to start doing your own repairs?
When the float is lowered in the storage tank, the contacts of the control circuit of the magnetic starter close. The most important thing to look for when choosing a unit is the insulation of the wire and the tightness of the plastic box.
The strip is attached to the handle through holes drilled in it with the appropriate screws. Hydrostatic sensors use the principle of measuring the pressure of a column of matter. If the float is used when working with dirty water and a large amount of solid fractions, then it, like the entire system, must be washed under running clean water. It is imperative to find out the characteristics of the material from which you plan to make the container. If the equipment is regularly rinsed with a stream of water, it will last much longer and will not lose its functionality even over time. Submersible pump repair. Replacing the cable.
Malfunctions and ways to eliminate them
There are a number of opportunities to repair the equipment yourself, provided that the broken part can be replaced with a new one or a simple technical procedure can be performed (for example, cleaning). To do this, you will have to disassemble the case, perform diagnostics, identify the problem and select an identical part.
Available actions include replacing the capacitor, impeller or float, repairing the electrical cable, fixing the shock absorber, and removing large pieces of clay and sand stuck inside the housing.
Advantages of the device
This procedure will prevent the float from sticking or sticking to the pump or discharge pipe. When the preparatory work is done, the float is connected to the pumping system.
Then the floats are mounted on the rod base. After this, the cable itself must be firmly fixed on the outside of the tank.
It is better to contact a specialized service center and purchase a branded certified part with documents that fully meets all the requirements for equipment of this type. They should be located on the sides of the body inside, so that the ball, falling between them, makes contact. It is the change in the indicators of this signal that makes it possible to assess the level of the substance in the container being used.
The cable of each switch is secured using clamps. Depending on the pressure value, the amount of water in the tank is determined. Thus, they can be easily adjusted manually to prevent overflow or dry running.
Equipment classification
This must be done at least once a month.
Three-core copper wire with a wire cross-section of 0.5 mm2. The fecal pumping equipment is switched on when the main control device is raised. I am involved in water supply and heating. It is adapted to work in high-density liquids and easily copes with the assigned tasks. It functions reliably and efficiently even in an aggressive environment and is not afraid of intense loads.
Their wires differ in color. Conclusions and useful video on the topic Rules for installing a mechanical float valve-switch to protect the storage tank from overfilling. The switch can be an element as part of the equipment during the construction of sewer communications. Water level indicator and simple warning circuit, construction site
Inexpensive industrial devices
There are also inexpensive models of liquid level control sensors, which can be purchased in stores for about 2 thousand rubles
Various modifications of ARS
Such float sensors are usually used in reservoirs. The measuring head in devices of this type is small, which makes the device compact. The load capacity, according to the operating instructions, can reach 1 ampere. The wire entry into the devices is sealed. The body is made of plastic. The operating differential is 45 degrees. The maximum pressure for correct operation of devices is 3 bar. The cost is about 2 thousand rubles, depending on the modification.
“Crystal” container filling control devices
These float type sensors can be used in harsh environments. Very compact. The measuring head is 2.3 centimeters in diameter. The maximum pressure for correct operation reaches 3.3 bar. The wire input is made in the form of a plastic seal. The devices are equipped with a spark protection barrier. Can work in hot environments. The price is slightly higher than 2 thousand rubles, depending on the modification.
Burkle devices
These devices are designed for contaminated environments, but can also be used in clean ponds and clean water tanks. The maximum pressure for correct operation is 4.1 bar. The maximum possible load is 1A. It is possible to work in environments heated to 170 degrees, in liquids with a density of up to 3 kg per square meter. cm. The average price of the device is 2,200 rubles and depends on minor modifications made by the manufacturer.
Fine Tek and Wilo sensors
These float type devices can be used in harsh environments. They are used for drainage purposes and can also be installed in wells. The sensors can withstand loads up to 2 amperes. The measuring heads are compact and measure 2.5 cm. The wire inputs are made in a specialized seal. The cases are made of heat-resistant plastic. The devices are equipped with fuel probes, which allows their use in flammable environments. The price ranges from 2 thousand to 2500 rubles and also depends on the modification.
Wilo float-type devices are the cheapest, but are not functionally designed for aggressive environments and can only be used in clean water. The sensors have small measuring heads and are compact in appearance. The maximum temperature of use is 140 degrees. The operating differential is only 30 degrees. The maximum operating pressure does not exceed 2 bar. The price of such sensors fluctuates around 1900 rubles.
Device design
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Heavy switches. Depending on where the unit is used, the functions of the float may differ.
The use of float sensors with a vertical rod arrangement is much more common than horizontal indicators.
They must be on different sides of the housing so that the ball between them can make contact. Such a breakdown occurs quite often, and not only on drainage equipment, the wire is soft and flexible, but not durable, it is very easy to break it accidentally, but it is also not difficult to repair. The switch is then connected to the pump, and the device can be used for its intended purpose.
Operating principle of a float sensor
The float changes its position because there is air inside. The second label should correspond to the top one. It is necessary to provide the following pump operation algorithm.
If the water level has dropped, the float lowers, opening the valve and access to the water supply. The most common breakdowns of the unit include burnout of contacts in the electrical cable, damage to the insulating layer, violation of the seal of the housing and penetration of moisture into it.
As an intermediate relay P - Intermediate relay MY3, 3A ACB: Like 0 Dislike 0 Ask your question Answer the question Source: about water level sensors To regulate and control the level of liquid or solid sand or gravel in production, at home, use a special device . The brand is unknown and there is no way to find out. One will begin to fill the container when the float is in the lower position, and the second will start working when the switch is at the top. It is designed to regulate the liquid level in the container and protect the pump from dry running. Further work is as follows: First, wires with a cross-section of no more than 2 mm are soldered to the contacts; Next, the wires need to be insulated and placed in the housing; It is also necessary to carefully insulate the inside of the case; You will need to pour polyurethane foam into the float cavity and insulate the outer side of the housing; After this, you need to install loops at the ends of the case and connect the cord.
The wiring that is connected to the float switches is carried out using clamps. Installing a submersible pump with a float in a well Depending on the length of the wire from the load to the float, the values at which the pump turns on or off will change. How to choose a float level sensor for wastewater?
Source
Types of fill level monitoring products
Liquid level monitoring devices are divided into two main types: contact and non-contact.
Proximity sensors: description
They are used mainly in industrial processes and are divided into ultrasonic devices, capacitive, electrode, operating on the hydrostatic principle, and so on.
Such devices are used not only in water, but also in other environments, including aggressive ones. The circuit includes, in addition to the sensor itself, which is immersed or installed on the walls of the tank, a control controller, which is installed in a separate control unit outside the tank. Such systems are complex and expensive, and, therefore, unprofitable for use in domestic conditions. To control the filling level of the tank with water necessary for irrigation or plumbing, it is more advisable to use simpler and cheaper devices.
Characteristics of contact devices
The most common devices for monitoring the filling of tanks in this type are float-type contact sensors assembled on the basis of reed switches. The devices are simple, reliable and cheap. They are divided according to their location in a container with liquid:
- Vertical arrangement. A rod with a float and a magnet moves along a vertical tube on which the reed switches for turning the pump on and off are located.
- Horizontal placement. Installed in the upper or lower part of the tank wall. As the tank is filled, the float with a magnet attached to it rises on a transverse rod to the reed switch, which switches off the power supply to the pump.
Float sensors for filling control with various design features can be purchased in stores. The choice depends on the specific installation location of the device and operating conditions.
Floats on mounting rod
One tank can contain up to several switches, each of which has its own function: one controls the auxiliary pump, another controls the main pump, the third acts as an emergency water level sensor, and the fourth monitors overflow. In any case, the number of floats is determined by the number of connected pumps, as well as the need for protective devices in the system. Several floats are mounted on a special mounting rod. In its role, you can successfully use a plastic pipe securely fixed in the tank. The float switches are fixed on the rod at a distance from each other so as not to interfere with the work of the neighbor. The cable of each switch is secured using clamps. There are situations when necessity dictates the use of several rods at once for attaching floats. Taking into account operating conditions and project features, the number of float switches required to organize the work of a particular system is determined.
Rating of switches of the middle valuable segment
WATTS IGD
A high-quality product from a German manufacturer that can function for ten years without requiring complex maintenance. Supplied in a plastic case that is well sealed and does not allow water and dust to pass through.
The maximum operating temperature is 60 degrees. Thanks to the high-quality material, the product can be used even when pumping gasoline, without the outer layer being destroyed.
The average price is 1,900 rubles.
float switch ]WATTS IGD
Advantages:
- Durable housing;
- Durability;
- Easy to use;
- Efficiency;
- Switching angle – 95o.
Flaws:
- Not found.
Marco AS2
A good product made in Italy, which has a high service life and reliability. The main advantage of the device is the ability to control a small water level (from 20 to 50 mm). This is not found in every design, which makes the product unique.
The body is smooth and has no irregularities, which allows it to be used in any system. The outer part is made of impact-resistant plastic, which is also a good solution. Operating current – 10 A.
Sold at price: 1,900 rubles.
float switch Marco AS2
Advantages:
- Efficiency;
- Durability;
- Appearance;
- Strength indicators;
- Able to monitor low water levels;
- Wide range of applications.
Flaws:
- Not found.
Wilo WA 65
A quality product with a 5 meter cable that is suitable for installation in a variety of tanks. The insulation is performed at a high level, which prevents accidental breakage and depressurization. The body is made of durable material that can function at 55-60 degrees. The kit includes a special weight.
The average price is 2,000 rubles.
float switch Wilo WA 65
Advantages:
- Length of cable;
- Universal application;
- Convenience;
- Easy to clean;
- Efficiency.
Flaws:
- Not found.
Float in the pump device description of the element
Both the sump pump and the submersible float pump operate in conditions where debris can get into the fluid or it can run out. In the first case, solid waste fractions can severely damage the system. In order to avoid this, pumps are equipped with shut-off floats, which are activated when there is no water or when there is a large amount of debris in it.
Pumps can be placed and operated in various containers, wells or wells. Depending on where the unit is used, the functions of the float may differ. However, in all cases, the tasks of floats include:
- Adjusting the operation of the main pump;
- Adjusting the operation of the auxiliary pump and increasing its efficiency;
- Water level alarm;
- Overflow alarm.
A liquid level indicator is required to prevent the pump from running dry. An overflow alarm is necessary to eliminate the possibility of overfilling the tank in which the pump is located. This often leads to a short circuit in the device.
Devices with built-in submersible floats
In the case of a submersible pump, its housing is completely sealed, which allows it to be completely enclosed in liquid without causing damage to the device itself or performance. Such pumps are characterized by much greater power, since in addition to simple pumping, they also must raise the liquid to a certain height. And for this you need high pressure. If we compare them with surface-type pumps, submersible ones have the following advantages:
- Complete versatility. They are capable of pumping out contaminated water containing large elements.
- Considerable level of productivity.
- During operation, the device makes virtually no noise.
Flaws:
- Limitations regarding the immersion depth, which will be 30 cm. In addition, the motors of such equipment require constant cooling, and for this the device must be surrounded by liquid.
- The device needs to be cleaned from time to time, as does the float switch. Constantly being in dirty liquid, they become dirty very quickly.
- Repair work is difficult since the body of the float drainage pump is completely sealed.
Equipment classification
Float sensors can independently monitor the liquid level or send a signal to the control circuit. According to this principle, they can be divided into two large groups: mechanical and electrical.
Mechanical devices
Mechanical valves include a wide variety of float valves for the water level in the tank. The principle of their operation is that the float is connected to a lever; when the liquid level changes, the float moves this lever up or down, and it, in turn, acts on the valve, which shuts off (opens) the water supply. Such valves can be seen in toilet flush tanks. They are very convenient to use where you need to constantly add water from the central water supply system.
Mechanical sensors have a number of advantages:
- simplicity of design;
- compactness;
- safety;
- autonomy - do not require any sources of electricity;
- reliability;
- cheapness;
- ease of installation and configuration.
But these sensors have one significant drawback: they can control only one (upper) level, which depends on the installation location, and regulate it, if possible, then within very small limits. On sale, such a valve may be called a “float valve for containers.”
Electrical sensors
An electric liquid level sensor (float) differs from a mechanical one in that it itself does not shut off the water. The float, moving when the amount of liquid changes, affects the electrical contacts that are included in the control circuit. Based on these signals, the automatic control system makes a decision on the need for certain actions. In the simplest case, such a sensor has a float. This float acts on the contact through which the pump is turned on.
Reed switches are most often used as contacts. A reed switch is a sealed glass bulb with contacts inside. Switching of these contacts occurs under the influence of a magnetic field. Reed switches are miniature in size and can be easily placed inside a thin tube made of non-magnetic material (plastic, aluminum). A float with a magnet moves freely along the tube under the influence of liquid, and when it approaches, the contacts are activated. This entire system is installed vertically in the tank. By changing the position of the reed switch inside the tube, you can adjust the moment the automation operates.
If you need to monitor the upper level in the tank, then the sensor is installed at the top. As soon as the level drops below the set level, the contact closes and the pump turns on. The water will begin to increase, and when the water level reaches the upper limit, the float will return to its original state and the pump will turn off. However, in practice such a scheme cannot be used. The fact is that the sensor is triggered by the slightest change in the level, after which the pump turns on, the level rises, and the pump turns off. If the water flow from the tank is less than the supply, a situation arises when the pump constantly turns on and off, and it quickly overheats and fails.
Therefore, water level sensors for pump control work differently. There are at least two contacts in the container. One is responsible for the upper level; it turns off the pump. The second determines the position of the lower level, upon reaching which the pump turns on. Thus, the number of starts is significantly reduced, which ensures reliable operation of the entire system. If the level difference is small, then it is convenient to use a tube with two reed switches inside and one float that connects them. If the difference is more than a meter, two separate sensors are used, installed at the required heights.
Despite their more complex design and the need for a control circuit, electric float sensors allow fully automated liquid level control.
If you connect light bulbs through such sensors, they can be used to visually monitor the amount of liquid in the tank.
How does the switch work?
Despite the clear design, devices may differ in their method of operation:
- Device for water supply systems. This is the simplest and most common way to use the product. The principle of operation is simple: when the product is on the surface, the pump begins to pump water from the container. The sensor automatically sends an electrical signal to the water pumping equipment. The station switches off when the switch reaches the bottom.
- The principle of operation in the sewer system. The electric fecal pump is turned on when the main control device rises to the surface. The auxiliary equipment begins to function when the sensor sinks to the bottom. It is important to know that one such float is capable of working with two pumping devices at once. At the same time, this does not affect the quality in any way; performance remains at the same level. In addition, the two-pump design is highly efficient because there is no problem with fluid delivery.
Float maintenance and repair
Subject to the operating rules, the float to turn on the pump will work for a long time and properly. If the element is used in conditions of working with clean water, then it does not require special maintenance. If the float is used when working with dirty water and a large amount of solid fractions, then it, like the entire system, must be washed under running clean water. This must be done at least once a month. This will prevent the part from sticking to the pressure pipe or pump.
If water gets inside the float, its contacts burn, or the integrity of the cable insulation is damaged, all faulty elements must be replaced, since they cannot be repaired. If the electronic float itself is completely out of order, then it must be changed at special service centers.
How to connect a float switch to a pump
Installation of the float can be done in different ways. Before installation, make sure that the current consumed by the pump is less than the maximum permissible current specified in the system operating manual.
The easiest way to install a float is to install it in a container using a cable and a special sinker, which is included with the unit. Installation of the float is carried out according to the following algorithm:
- First, the sinker must be put on the cable and the free play of the float must be determined;
- After this, the sinker must be secured to the cable using a latch;
- Next you will need to fix the cable on the outside of the container.
After installing the element, you should connect the float switch to the pump. Before setting up the float, you need to carefully study the diagrams that come with the device.
Once connected, you will need to check if the system is working. To do this, start the pump and wait a couple of hours. If the device pumps out water stably, it means that the installation and connection were carried out correctly.
Float switch in action
Before connecting a newly purchased float switch to a pump, it is advisable to ensure that their technical characteristics are compatible. An elementary way to set up the operation of a switch for electric pumps is inside a water tank.
Serial connection diagram for float switch:
- A special sinker (from the kit) is attached to the float cable.
- The cable is securely fixed at the edge of the tank.
- The amplitude of the free movement of the float switch is adjusted to set the highest and lowest levels at which the float switch will operate.
- The float switch is connected to the pump last.
The main functions performed by a float switch:
- The float connected to the pump that performs the task of filling the tank will turn off when ascending and connect when it reaches the bottom mark.
- For an automatic station: switching on when the upper liquid level mark is reached and switching off at the lower mark (reaching the bottom of the container).
- Valves or valves with a servo drive: the switch will give a signal to close when it is in the upper position (full capacity) and will open the way for water when it reaches the lower position.
- Control room: monitoring of excess and shortage of water.
It is possible to connect two pumping devices to one float: the function of the first pump is to fill the tank when the float is located at the bottom, the mission of the second is to pump out water when it is at the top. The scheme is effective only if there is an uninterrupted supply of water to the tank. Some options for connecting switches to prevent pumps from running dry.
Design and principle of operation of the switch
Float design: electric switch and steel ball placed in the internal cavity of a plastic housing. The cable length varies from 3 to 10 m. When the float switch reaches the upper mark, the switch contacts close, turning on the pump. As soon as the float descends to the lower mark, the steel ball acts on the switch lever, changing its location. The circuit opens and the system turns off.
Float switch connection diagram: a cable with three wires is connected to the switch. They vary in color, often being black, blue and brown. The common wire is marked in black. In the upper location of the float switch, the contacts of the common wire and the normally closed wire, indicated in brown, are closed. At the minimum mark, the circuit is closed with the participation of a common wire and a normally open wire, indicated in blue. The insulation of wires not currently used in the circuit must be very reliable. It is understood that in an aquatic environment the cable must have sufficient moisture resistance, and the plastic case must be leak-tight. The cable outlet is equipped to relieve mechanical stress and is reliably sealed. The polymer resin filling the cavity of the cable glands prevents moisture from getting inside. And the last word in favor of the float switch is the price, which usually varies from 300 to 500 rubles. The combination of a reasonable price and reliability makes the purchase of a float switch the best option for providing protection against unwanted breakdowns of expensive equipment, such as household and industrial pumps.
The role of alarms in drainage pumps
A drainage pump with a float switch is widely used both in industry and in everyday life. Its scope of use is cleaning wells, removing dirty liquid, etc. In a drainage pump, the float is equipped with the function of turning the drive on and off automatically. The switch is lowered into the wastewater via an extended cable along with a pipe for collecting liquid. The vertical type drain pump kit includes a vertical float switch with the function of pumping liquid out of a confined space. Such a drainage pump can, for example, drain inactive pipelines.
Calculator of the required performance of a drainage pump used for watering a garden
Not every pump creates a pressure greater than 1.0-1.5 atm. The pressure is often not enough for irrigation, so liquid intake points are brought as close to the site as possible. This is possible if you place several containers in which the water settles and then is collected. Under such conditions, the performance of the drainage equipment is sufficient for irrigation.
Each plant needs its own amount of water per 1 m². Knowing the norm, they calculate how much liquid will be needed for irrigation. The calculator takes into account all the conditions to calculate what pump performance is needed and pump the required amount of water in a limited time.
Pump for watering a garden with a float.
Making a float switch with your own hands
To make a part yourself, you will need to prepare:
- Metal ball;
- 2 buildings;
- 2 small magnets;
- Contact plates.
The plates can be made of brass or copper. They must be on different sides of the housing so that the ball between them can make contact. To make the metal strips more springy, they can be placed on a file and beaten with a hammer.
The magnets should lift the ball and hold it at an angle of 65 degrees. The housing itself can be made of any material that does not conduct electricity. Further work looks like this:
- First, wires with a cross-section of no more than 2 mm are soldered to the contacts;
- Next, the wires need to be insulated and placed in the housing;
- It is also necessary to carefully insulate the inside of the case;
- You will need to pour polyurethane foam into the float cavity and insulate the outer side of the housing;
- After this, you need to install loops at the ends of the case and connect the cord.
The manufactured float will last quite a long time, and you will save a lot of money on the purchase of equipment.
Design and principle of operation of the drainage pump
The design of the drainage pump is quite simple; its main elements are:
Rice. 3 Internal structure of the drainage electric pump
Frame
A typical drainage system has two bodies: external and internal. The internal casing houses the main unit of the device - an electric motor, which is cooled by the water flow washing it, flowing between the casings to the outlet located at the top.
The outer body of the device is equipped with a convenient handle for carrying or hanging in the water column; it also contains an outlet pipe (pipe) to which hoses are connected.
The inner case is made of metal to organize better cooling; the outer case is usually metal (stainless steel) or impact-resistant plastic.
Electric motor
In the internal, completely insulated pump casing, there is an electric motor consisting of a stator with a winding and a rotor, the shaft of which rotates on the upper and lower bearings. Power is supplied to the electric motor using a cable through a sealed input unit; a capacitor is built in for starting.
To lubricate and cool the bearings, special chambers are provided in the lower part of the inner housing, filled with technical oil. There are also O-rings there that prevent water from penetrating into the engine.
Working wheel
The disk-shaped impeller, on which curved blades are placed, is fixed to the motor shaft. The usual material for its manufacture is metal, sometimes it is made of high-strength plastic.
At the bottom of the pump body there is a stand with legs on which the pump is usually placed. A little higher is a cover with water intake holes (filter), eliminating the possibility of particles with sizes exceeding its technical characteristics from penetrating into the electric pump.
What material is used to make devices
Often, modern models of float drainage pumps are made from cast iron and stainless steel in combination with other materials that will be needed to assemble the device body and other necessary parts. They are subject to a fairly simple comparison:
- stainless steel. A fairly reliable and time-tested material with a service life of decades;
- cast iron. The strength of a device made from this material will be amazing, but its weight will be enormous, and the cost will be quite high;
- plastic. It is the cheapest material, the durability of which is low.
Equipment whose body is made of plastic, while the wheel itself is made of steel, is in considerable demand. It is excellent and the best value for money. Relatively recently, several models of these units entered the market, the working blades of which are made of technical polymer. They are cheaper than their high-tech counterparts. They are characterized by durability, strength and practicality.
