A pressure switch is equipment that is used to maintain the set pressure on the pumping equipment and in the line to which it is connected. What is a pressure switch for a pump, how to choose, install it? You can find out the answers to these questions from this article.
The design provides for the presence of sensors and controllers acting as sensitive elements. They measure the readings of the controlled parameter, after which they are converted into a form convenient for processing and transferred to the relay. Based on this information, the relay fulfills the programmed operations and restores the normal operation of the system.
Destination
The water pressure switch for the pump (the connection diagram is shown below) is used to automate the procedure for saving the set parameters. What makes this device in demand in all systems in which control is providedclosed-loop control processes.
Classification
Today, the pressure switch is classified according to the following indicators:
- Limits for measurement and control.
- Availability of additional contacts.
- Installation method.
- Degree of protection.
- Input signal type and level.
- Power type (external or autonomous).
Design Features
The water pressure switch for the pump (the connection diagram is given below) is an electronic-mechanical equipment that turns off and starts the pumping unit at certain pressures in the water supply network.
Devices produced by different manufacturers are structurally similar, the differences are only in minor details. Switching off and supplying power to the pumping unit is carried out by opening and closing the contact group - the main element of the relay. The equipment also includes two springs and a piston with a membrane.
After connecting to a special station adapter, fluid pressure begins to act on the membrane, which, in turn, acts on the piston, which is connected to the contact group.
A large spring acts on the contact group from the opposite side, the compression of which is regulated by means of the corresponding nut. If due to water intake in the systemwater supply pressure drops, the spring overcomes the impact on the piston side, and the contact group closes, supplying power to the pump.
When the pressure in the pipeline increases, the piston will carry out a gradual displacement of the platform with contacts, overcoming the resistance of the spring. However, the contacts do not immediately open, this only happens as a result of moving a certain distance, depending on the degree of compression of the small spring. Like a large spring, it is seated on a stem with a nut. As a result of contact opening, the pump unit is switched off.
Station operation principle
The water supply system automatically supplies water to the tap under a certain pressure. The design of the station provides for: a hydraulic accumulator, a pump, as well as a water pressure switch for the pump. The connection scheme involves the pumping of liquid, which moves through the pipeline and passes into the accumulator, which is a kind of reservoir for the accumulation of liquid.
Inside the accumulator there is a membrane, which, when liquid enters, compresses the air and increases in size. After that, when the tap is opened, water begins to flow out of it with a certain pressure, when it is closed, the movement of water stops.
At this moment, the pressure becomes less than the set parameter, and the relay automatically activates the pump and water begins to flow into the tank again. It comes until the filling limiter is activated and the pump stops using the relay.
Water pressure switch for pump: connection diagram,working principle
The relay is a block with springs that are responsible for the dimensions of the maximum and minimum fluid pressure values. The springs are adjusted using special nuts.
The force of water pressure is directed to the membrane, and when it drops to a minimum value, the spring is weakened. When the maximum pressure is reached, the diaphragm overcomes the resistance of the spring. This behavior of the membrane causes either the inclusion or deactivation of water. That is, as a result of the action of the membrane on the spring, the contacts under the housing cover close or open.
As soon as the liquid level indicator reaches the minimum value, the electrical circuit closes, energizes the pump, which starts to work.
Pumping equipment pumps water to the maximum level, after which the electrical circuit closes, the voltage supply ends and the unit stops working.
Connection
Let's consider how to connect a pressure switch (see wiring diagrams below). These blocks for connecting water have a non-standard input. Household relays typically have a four-inch input, while professional devices may have a larger input. For this reason, it is advisable to take care of the adapter in the first place.
Until a certain time, in the manufacture of pumping equipment, a standard part was used, called inpeople "herringbone". This adapter is a brass piece of pipeline 100-120 mm in size and 25 mm in diameter. One end is connected to the pump inlet. The outlets at the adapter are taps for connecting the water line, pressure switch and other equipment.
Currently things are looking a bit more complicated. For modern pumping units, the relay is screwed directly into the equipment, or into places that at first glance are the least suitable for this.
First of all, the pump is connected to the water source, then to the power supply. Adjustment and tuning is already the final, third stage of work.
Need adjustment
Adjusting the pressure switch for the pump (how to set it up will be discussed below) may be required for the following reasons:
- If for some reason you are not satisfied with the factory settings.
- If the pumping station is assembled on site.
DIY adjustment
If for some reason the factory settings of the pumping station did not suit you, then the connection and adjustment of the water pressure switch are carried out independently. This will require a screwdriver or wrench. You will also need a wrench to tighten (unscrew) the nuts of the regulators. Do not forget that if the components of the station fail, the product loses its warranty. If the result of the violation was an incorrect connection diagram of the submersible pump, the connection as a whole was performed incorrectly - all this is not a valid reason formanufacturer.
Start setting should be disconnected from the voltage relay. After that, the cover covering the relay is removed and adjustment is carried out as desired, for example, to increase pressure, measure or reduce the response range.
Decreasing or increasing pressure
Based on the above, to decrease or increase pressure without changing the range at which the relay operates, it is only necessary to tighten or unscrew the nut on the large regulator.
Changes in response range
If, for example, you are satisfied with the lower threshold, and you only need to increase or decrease the upper threshold, then a smaller regulator is used.
In the process of tightening the nut of this regulator to the right, the upper threshold will increase, without changing the lower one. When weakened, the process will occur exactly the opposite, that is, the difference between them will increase or decrease.
After adjustment, the voltage is turned on, the pressure gauge marks the moment when the pump was turned off (upper pressure).
It happens that the value of the switching torque and the response range are not suitable, then in this case the adjustment must be performed with a large regulator, and then with a smaller one, monitoring the process on a pressure gauge.
Pressure switch for water pump: connection, price, reviews
According to reviewsconsumers, today the relay of the Danish company Danfoss is more popular, its pressure range is 0.2-8 bar. The cost of such equipment is about 3000 rubles. A device from the German manufacturer Grundfos with similar characteristics already costs 4,500 rubles. Italian It altecnica equipment with standard settings will cost about 500 rubles.
Domestic devices of the company "Dzhileks" are almost identical to Italian ones, but their cost is about 300 rubles. Thus, domestic products turn out to be much less expensive, and in terms of their characteristics, they are practically not inferior to Western models.
Experts recommend installing equipment from one manufacturer, that is, if you purchased a German pump, then the pressure switch must be from the same manufacturer.
Now you know what the connection diagram of the pressure switch looks like, how to connect it correctly will no longer cause you any special questions.
