Pump diagram and pump connection diagram. Which pump to choose? With built-in or remote ROM

Water pressure stabilizers

There are many reasons to turn on domestic pumps through a soft starter.

Usually, a submersible or surface pump is connected through an electromechanical or electronic relay, an automation unit or a magnetic starter. In all these cases, mains voltage is supplied to the pump by closing the contacts, that is, through a direct connection. This means that we apply full mains voltage to the stator windings of the electric motor, and the rotor does not yet rotate at this time. This leads to the appearance of an instant powerful torque on the rotor of the pump motor.

This connection scheme is characterized by the following phenomena when starting the pump:

Current surges through the stator (respectively, through the supply wires), since the rotor is short-circuited.
In a simplified sense, we have short circuit on the secondary winding of the transformer. According to our experience, depending on the pump, the manufacturer and the load on the shaft, the pulsed starting current can exceed the operating current from 4 to 8, and in some instances up to 12 times.

The sudden appearance of torque on the shaft.
This has a negative effect on the starting and working stator windings, bearings, ceramic and rubber seals, significantly increasing their wear and reducing the service life.

The appearance of a sharp torque on the shaft leads to a sharp turn of the borehole pump housing relative to the pipeline system.
We have repeatedly witnessed how, because of this borehole pump disconnected from the pipelines and fell into the well. When pumping station on the base surface pump installed on the accumulator platform, this leads to loosening of the fixing nuts and destruction of the weld points and seams of the accumulator. Also, when the pump is turned on directly, the service life of plumbing and shut-off valves is reduced, especially at their junctions.

It is generally accepted that the accumulator removes water hammer in the water supply system.
This is true, but water hammers disappear in pipelines only starting from the place where the accumulator is connected. In the gap between the pump and the accumulator, when the pump is connected directly, the water hammer remains. As a result, in the interval from the pump to the accumulator, we have all the consequences of a water hammer on all parts of the pump and on the pipeline system.

In water filtration systems, water hammer, which occurs when the pump is directly connected, significantly reduces the life of the filter elements.

If the local power grid weak, then your neighbors will also know about the start of a pump with a power of more than 1 kW with a direct connection by a sharp drop in the voltage in the network at the moment the pump is turned on.
If the local network EXTREMELY WEAK, and your neighbor also enjoys life by connecting to the network all available electrical devices, then a well pump submerged to a great depth may not start. Such a power surge can damage electronic devices connected to the network. There are cases when, when starting the pump, an expensive refrigerator stuffed with electronics failed.

The more often the pump is turned on, the less its service life.
Frequent starts through a direct connection lead to failure of the plastic couplings of borehole pumps connecting the electric motor to the pump part.

You and I went through the problems that arise when starting the pump without soft starters (UPP) .

It should be noted that even when the pump is turned off without SCP with a direct connection scheme, there are negative points:

When the pump is turned off, a water hammer also occurs in the system, but now due to a sharp decrease in the torque on the pump shaft, which is tantamount to creating an instantaneous vacuum.

A sharp decrease in the torque on the pump shaft also leads to the rotation of the pump housing, but in the opposite direction.
Think about the pipelines and threaded connections of the pump.

In ordinary household pumps electric motors are asynchronous and have a pronounced inductive character.
If we abruptly interrupt the supply of current through an inductive load, then there is a sharp voltage jump on this load due to the continuity of the current. Yes, we open the contact, and all the high voltage should remain on the pump side. But with any mechanical opening of the contact, the so-called "contact bounce" is present, and the impulses high voltage get into the network, and therefore get into the devices connected at that time to the network.

Thus, with a direct connection of the pump, there is increased wear on the mechanical and electrical parts of the pump (both during start-up and during shutdown). Devices connected to the same network also suffer, and the service life of filtration systems and plumbing fittings is reduced.

Usage soft starters ("Aquacontrol UPP-2.2S") allows you to smooth out most of the shortcomings described above. In device UPP-2,2S a specially calculated voltage rise curve on the pump has been implemented, which allows, on the one hand, to start the pump with guarantee in the most adverse conditions operation, and on the other hand, smoothly increase the shaft speed. Also, protection against low and high voltage of the mains is built into this device to protect the pump from extreme operating modes and switching on.

IN UPP-2,2S phase triac control is used. At the moment of start-up, a part of the mains voltage is supplied to the pump, which creates a torque sufficient to guarantee the start of the pump. As the rotor spins up, the voltage on the pump gradually increases until the voltage is fully applied. After that, the relay turns on and the triac turns off. As a result, when using UPP-2,2S the pump is connected to the network through the relay contacts, that is, in the same way as with a direct connection. But for 3.2 seconds (this is the soft start time), the pump is energized through the triac, which provides a “soft start”, without sparks on the relay contacts.

With such a start, the maximum starting current exceeds the operating current by no more than 2.0-2.5 times instead of 5-8 times. Using UPP-2,2S, we reduce the starting loads on the pump by 2.5-3 times and prolong the life of the pump by the same amount, provide more comfortable operation of devices connected to the electrical network. UPP-2,2S can be called a device with resource-saving technology.

Often faced by owners country houses and cottages, the owners sooner or later face such a problem as providing water supply to their homes.

It is possible to constantly bring water and store it in large containers only at the construction stage, and subsequently the problem of water supply is solved in other ways. One of them is the arrangement of a separate well at the site.

A pump is installed in it for uninterrupted water supply. Such a pump can supply water not only to the house, but also to the garden.

The scheme of such a pump and its characteristics are considered in detail. IN in general terms centrifugal pump consists of
- rotor and stator
- impeller and shaft
- guide vane and housing
- discharge and suction pipes.

A bit of theory

To improve performance, the design of the pump can be changed.

Structural diagram of the parallel connection of the pump wheels

At parallel connection each impeller supplies only part of the total flow, creating a full head, the flow in the pump is divided into a number of parallel jets. Such pumps are called multi-flow.

When entering the pump, the flow is divided into two parts and enters the impeller from two sides. The impeller in this case is a combination in one part of two impellers located symmetrically with respect to a plane normal to the axis of the pump. When leaving the impeller, both parts of the flow are reunited and enter the spiral outlet.

The design of such a pump is very compact.

Structural diagram of the serial connection of the pump wheels

When connected in series, each impeller creates only a fraction of the total head at full flow, the head in the pump increases in steps.

This type of design allows you to increase the pressure of the pump as many times as it has steps. All wheels are mounted on a common shaft and form a single pump rotor.

Axial pressure balancing system, bearings, seals are combined in one housing common for all stages, which makes the pump compact, reduces weight and reduces cost.

The connection diagram of the submersible pump is needed in order to see in what order all parts are connected.

The first step is to determine the depth of the well. The depth of the well is determined by the depth ground water. It must be remembered that the distance from the bottom of the well to the pump must be at least 1 meter. The distance from the top of the groundwater to the surface of the earth is called the dynamic level.

To ensure uninterrupted all-season use of the well, it is equipped with special well- caisson. The depth of the caisson should not be less than the depth of freezing of the soil.

1. The pipe coming out of the well into the caisson is cut and connected to the pipe laid in the trench leading to the house. Thus, the pipeline located in the trench leading to the house must be located at a depth not less than the freezing depth of the soil - i.e. at the level of the lower boundary of the caisson. It is recommended to lay two pipes in this trench: the first labor is water supply, the second is electrical wiring.

A coarse filter must be installed directly in front of the pressure control unit and the hydraulic accumulator. Additionally, the same filter is installed at the outlet of the accumulator before water is supplied to the pipeline system of the house, but this requirement is advisory in nature.

Electrical connection diagram of the pump

Connecting the pump directly to the power supply threatens to quickly break down the centrifugal unit and the main reason is that the pump will continue to idle even when the water level drops. For household systems water supply the right option is the inclusion of factory automation units in the water supply scheme. Such blocks are called - pump control stations or hydraulic controllers.

The main functions of the hydraulic controller:
Soft start and soft stop of the pump;
Automatic maintenance of pressure;
Protection of the pump from power surges;
Protection against lack of water level in the well;
Network overload protection.

Such block automatic control a well pump is a very necessary device and therefore, reputable companies include it in the pump package, often with limited functionality.

AND circuit diagram pump connection in this case is as follows.
1 - control unit
2 - pump cable with plug
3 - cable with socket
4 - circuit breaker
5 - socket with grounding
6 - pump
7 - pump cable
8 - nipple
9 - check valve
10 - injection pipeline
11 - cross
12 - adapter nipple
13 - metal hose
14 - hydraulic accumulator
15 - pipeline

However, for more long work of the automation unit, it is necessary to add a contactor to the connection diagram of the borehole pump, which will ensure the simultaneous switching on of the automation unit with the submersible pump.

Contactor is a highly reliable product designed to control electrical loads requiring a large number on/off.

Pump relay wiring diagram

In some cases, in order to save the final cost of the pump kit, the connection is made without a control box. Only a pressure switch is used.

The pressure switch ensures that the pump is disconnected from the electrical network when the upper limit of the water pressure in the accumulator is reached and the pump is turned on when the water pressure reaches below the lower limit.

Simultaneously with the connection of the pressure switch to the pump, an automation unit is added to the circuit, which protects the pump from running dry (lack of water level in the well).

The electrical circuit for connecting the pressure switch and pump automation in this case is as follows.

The pump connection diagram must be made only with a special submersible cable that provides reliable grounding. A standard waterproof cable will not work in this case. The length of the wiring is equal to the sum of the dynamic level of the pump plus the distance from the well to the boiler room.

The cable is attached (soldered) directly to the pump, the insulation is made with a heat-shrinkable fluid coupling. The heat shrink process itself is quite complicated, especially when performed for the first time, so it is recommended to leave this procedure to professionals, since exceeding the heat shrink time threatens with loss of elasticity and water resistance, and insufficient heat shrink is characterized by incomplete waterproofing of the cable.

Connection of PZU (starter protection device) for submersible pumps

The start-up device is designed for the initial start-up of the pump and for the subsequent acceleration of its engine. Starting is the most unfavorable mode for electric motors and in order to prevent Negative consequences arising at start-up is set by the ROM of the pump.

The ROM serves to protect the electric motor by current, carrying out its automatic shutdown when an overload occurs. This is done using a thermal relay located in the pump housing.

In addition, the device (together with the relay) includes:
- condensate block
- terminals

All these elements are combined into a common electrical circuit.

Scheme of connecting the pump to the accumulator

The hydraulic accumulator is one of the most important components of the water supply system at home. The accumulator is used to store water, maintain pressure in the plumbing system and, if necessary, add water to the pipeline (for example, when pressure drops).

The accumulator is a metal container with a rubber membrane inside.

The scheme of the deep pump, when connected to a hydraulic accumulator, must include a pressure switch and a pressure gauge. For ease of maintenance and pressure control, the accumulator is located in the boiler room of the house. Factory settings of the pressure switch: lower - 1.5 bar, upper - 2.8 bar.

Before connecting the pump to the accumulator, make sure that there is pressure in the tank. The pressure in the tank must NOT exceed the pressure set on the switch. The recommended pressure value of the accumulator tank should be 0.2 - 1 bar less than the pressure set on the relay.

4. Preparation for lowering the pump into the well. Scheme submersible pump to ensure the supply of water to the house must contain: barrel + check valve + fitting. All threads are sealed with FUM tape, except for the metal-plastic transition. Anpak paste plus linen tow is used here.

Before lowering the pump into the well, immediately after trimming the pipe coming out of the well, the lower part of the head and the rubber ring seal are put on it. Each connection must be carefully sealed to protect the system from leakage.

Lowering the pump into the well is carried out using a cable made of of stainless steel 4-5 mm in diameter. I select the cable with a margin of two to three meters, in order to be able to fix it at the ends: on the one hand, this top part pump (pulled through special holes), special clips (or a rivet) are attached to the other side. The clamps are carefully wrapped with electrical tape.

The pipe through which the pump will supply water to the house must be straightened on a flat surface. A power cable is unwound nearby, also with a cable. The pump is ready to run.

5. Lowering the pump into the well. The scheme of the submersible pump in the well is as follows. With the help of building ties, every 1.5 - 2 meters it is necessary to fix the cable in the pipe.

After descending to casing pipe put on a well cap. It is possible to thread a water hose, cable and cable through the opening of the head in advance, before descending. The cap will protect the well from debris.

6. Connect the condenser and check the operation of the pump. If the water is pumped out, then you can cut the pipe near the head and connect it to the pipe laid in the trench to supply water to the boiler room. The connection is made through a coupling with a collet clamp.

7. Plug the pump into a power outlet

The warning light on the control panel lights up. We turn on the water supply in order to release air from the system. The pump starts to work, and water enters the accumulator. The sound of water should be heard.

After the air is released, water begins to flow. We close the tap. We follow the readings of the pressure gauge: the pump is turned off after a pressure of 2.8 bar is injected. Then we turn on the water from the tap and check the operation of the pump after the pressure drops to 1.5 bar. The pump is back in operation. So the cycle of work is repeated.

If you tightly connected the entire system, then the pump will turn on and off in accordance with its settings. Pump connection successfully completed.

The installation scheme is not distinguished by the high complexity of the work being carried out, but it requires careful and consistent execution of each stage of work. In order for the equipment to serve you long term and there were no breakdowns, carefully consider each stage of work. IN ideal- Seek professional help.

Dear luminaries!
I have a well pump connected through a starting-protective device. Both the pump (some Chinese, 1.5 kW) and the ROM were installed 10 years ago. Today I carried out an annual preventive maintenance: I adjusted the on / off pressure and pumped up the GA. Then he started the pump for watering. After 10 minutes of work, the ROM worked. I have such a ROM (see the file in the attachment). It has a red light and a safety button on the right. So the red light was on, and I managed to bring the ROM back to life by pressing the fuse button.
Turned the pump back on and started pumping water. More so far, the ROM did not work, although I collected about 750 liters of water in the tank, but the red light was on all the time until the pressure switch turned off.
Tell me, please, what is usually the reason for the operation of the ROM?
There is such a capacitor in the ROM (see the file in the attachment). Maybe he has lost his characteristics over 10 years of work and needs to be replaced?
Thanks in advance.

The answer may be belated, but if you have a 1.5 kW pump, then its operating current is about 6.8 A, given that the thermal relay is selected from the condition 1.2 of the operating current, then it should be 8.2 A. According to the data on the cover of the control unit, there is an 8 A thermal relay, that is, it is at the very border of the operating range, without a margin at all. And a short operation of the pump with an overload caused by wedging of the impeller or screw, pinching the hose for irrigation with increasing pressure, etc., could cause the protection to trip.
Have you done any prophylaxis? If so, what was revealed, and how does the pump work at the present time?
Why did you ask the question, I myself started to fail the control unit 1.5 weeks ago. The pump was turned on for 20 seconds, then turned off, and since the pressure had time to rise above the turn-on pressure, the pump did not turn on until the pressure dropped again. By blocking the pressure switch, it was possible to find out that the first switching on of the pump lasts 20 seconds, then the ROM turns off for 8-10 seconds until the thermostat cools down, and then the second and all subsequent switchings work in a cycle of 8-10 seconds it works, 8-10 seconds it rests while raising the pressure by 0.05 bar. So the thermal relay should not work, when triggered, it should turn off, and you can turn it on by pressing the button. And in order to pump up the accumulator from 2 bar to 3.5 bar, you have to wait 10-15 minutes in this clocking mode. I touch the thermostat, it is not higher than 30-35 degrees. The machine on the 10 A shield does not work. The thermostat is also 8 A.
I conducted an experiment, shorted out the thermal relay, after which the pump began to pump water from 2 to 3.5 bar in 2.5-3 minutes.
I took a current clamp this weekend to check the current consumption of the pump. When starting for 10-20 seconds, the current consumption is 5.2 A, then it starts to drop to 4.8 A, and at the end of the cycle, when the pressure rises to 3.5 bar, the current consumption drops to 4.5 A. The pump is 0.75 kW, for which the rated current consumption should be about 3.4 A, well, taking into account losses cosFi = 0.8, then about 4.3 A. The pump is also Chinese, there can be anything. Therefore, I think that everything is in order with the pump so far, the thermal relay just broke, and it’s very strange, it works at a current of 5 A, and the contact breaks, and then automatically turns on, but for a shorter time. I will change it.

High inrush current is a problem for systems with limited maximum power. The machine can knock out, the uninterruptible power supply system goes into overload mode. How to be?

A good solution would be to use a soft starter (SCP). For example, we have a single-phase submersible pump with a power of 1 kW, located in a well at a depth of 50 meters. To start its engine, 4-6 times the starting current is required, i.e. the system must withstand a short-term power of about 5 kW. Let's say an inverter designed for 3kW simply will not be able to start. The moment of launch will also be accompanied by a sharp increase in pressure, which actually means a water hammer on the water supply system.

Insert the soft starter into the line feeding the pump. The device, within a specified time (usually up to 20 seconds), will gradually increase the voltage, which will allow the pump to spin the impeller with acceleration, without jerking. As a result, we equated the starting current to the nominal value, i.e. it amounted to 1 kW and significantly extended the life of the submersible pump (the service life increases by about 2 times, given the cost of the pump, the decision to use soft starter, even in the absence of an energy backup system, becomes obvious):

Imagine a connection diagram that can be used with both single-phase and three-phase equipment:

Are there restrictions on the use of the soft starter? Yes, there are, and you should be aware of them:
1) Soft starters cannot be used with refrigerators. High starting current is needed to stall the compressor valves
2) Similarly for air conditioners and other equipment

If you have any questions, I'll be happy to answer in the comments!

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