Starting protection device for a well pump. Automation for the pump: types of equipment and installation diagram Starting and protective device of the well pump connection diagram

Each industrially produced pump has its own purpose and specific application. If you have already selected equipment for pumping water or other liquid in accordance with the required operating parameters, then you need to know that ROM is usually used in equipment with a fairly high productivity. These are submersible pumps with single-phase asynchronous motors and a fairly large immersion depth.

The launch equipment is remote, i.e. is placed at the top and connected to the pump via a cable connection. When servicing this equipment, there is no need to lift the pump, there is no dismantling and subsequent installation of the water main, which simplifies operation and reduces the dimensions of the pumping unit itself.

There are many brands of pumps on sale, the so-called economy class, for household use and relatively low performance. They are installed, as a rule, at shallow (up to 10 meters) depths. Such pumps are economical and compact; the starting equipment does not take up much space and is located directly in the device housing.

The built-in ROM has its advantages in saving cables (only the line of a regular household electrical network), saving the cost of additional equipment for the pump, and ease of use.

Direction of the right choice

Owners often have to country houses and cottages, the owners sooner or later face the problem of ensuring water supply to their homes.

Constantly bring water and store it in large containers is possible only at the construction stage, and subsequently the problem of water supply is solved in other ways. One of them is the installation of a separate well on 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 diagram of such a pump and its characteristics are discussed in detail. IN general outline centrifugal pump consists of
- rotor and stator
- impeller and shaft
- guide vane and housing
- discharge and suction pipes.

A little theory

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

Structural diagram of parallel connection of pump wheels

With a parallel connection, each impeller delivers 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 both sides. The impeller in this case is a combination in one part of two impellers located symmetrically relative to the plane normal to the axis of the pump. When leaving the impeller, both parts of the flow are reconnected and enter the spiral outlet.

The design of such a pump is very compact.

Structural diagram of a series connection of pump wheels

With a series connection, each impeller produces only a portion of the total head at full flow, the pump head increases in steps.

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

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

A connection diagram for a submersible pump is needed to see in what order all the parts are connected.

The first step is to determine the depth of the well. The depth of the well is determined by the depth of groundwater. 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 point of groundwater to the surface of the earth is called the dynamic level.

To ensure uninterrupted all-season use of the well, a special well - a caisson - is equipped. The depth of the caisson must be no less than the depth of soil freezing.

1. The pipe coming out of the well into the caisson is trimmed and connected to a pipe laid in a trench leading to the house. Thus, the pipeline located in the trench leading to the house must be located at a depth no less than the depth of soil freezing - i.e. at the level of the lower boundary of the caisson. It is recommended to lay two pipes in this trench: the first is for water supply, the second is for 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 hydraulic accumulator before supplying water to the pipeline system of the house, but this requirement is advisory in nature.

Electrical diagram for connecting the pump

Connecting the pump directly to the power supply risks rapid breakdown of the centrifugal unit, and the main reason is that the pump will continue to idle even when the water level drops. For domestic water supply systems the right option is the inclusion of factory automation units in the water supply scheme. Such units are called pump control stations or hydraulic controllers.

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

Such a 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 electrical diagram pump connection in this case looks like in the following way.
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 - discharge pipeline
11 - cross
12 - adapter nipple
13 - metal sleeve
14 - hydraulic accumulator
15 - pipeline

However, for more long work automation unit, it is necessary to add a contactor to the connection diagram of the well pump, which will provide simultaneous activation automation unit with a submersible pump.

Contactor is a highly reliable product designed to control electrical loads that require large quantity on/off.

Pump relay connection diagram

In some cases, in order to save the final cost of the pump kit, the connection is made without a control unit. Only the 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 connecting 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 diagram for connecting the pressure switch and pump automation in this case is as follows.

The pump connection diagram should only be made using a special water-submersible cable that provides reliable grounding. A standard waterproof cable will not work in this case. The wiring length 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 performed with a heat-shrinkable fluid coupling. The heat shrinking 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 loss of elasticity and water resistance, and insufficient heat shrinkage is characterized by incomplete waterproofing of the cable.

Connecting ROM (start protective device) for submersible pumps

The starting protection device is designed for the initial start 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 that occur during startup is set by the pump ROM.

The ROM serves to protect the electric motor by current, automatically turning it off 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.

Connection diagram of the pump to the hydraulic accumulator

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

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

The circuit of a deep-well pump, when connecting it to a hydraulic accumulator, must include a pressure switch and a pressure gauge. For ease of maintenance and pressure control, the hydraulic 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, you must make sure there is pressure in the tank. The pressure in the tank must NOT exceed the pressure set on the relay. The recommended pressure value of the accumulator tank should be 0.2 - 1 bar less than the pressure set on the relay.

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

Before lowering the pump into the well, immediately after trimming the pipe coming out of the well, a Bottom part head and rubber sealing ring. Each connection must be carefully sealed to protect the system from leaks.

The pump is lowered into the well using a cable made of of stainless steel with a diameter of 4-5 mm. I select the cable with a reserve of two to three meters, so that it can be secured at the ends: on the one hand, this top part pump (pulled through special holes), special clamps (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. The power cable, also with a cable, is unwinding nearby. The pump is ready to drain.

5. Lowering the pump into the well. The diagram of a submersible pump in a well is as follows. By using construction screeds, every 1.5 - 2 meters it is necessary to secure the cable in the pipe.

After lowering, a well cap is put on the casing pipe. You can thread the water hose, rope and cable through the hole in the head before lowering. The cap will protect the well from debris.

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

7. We connect the pump to the outlet

The warning light on the control panel lights up. Turn on the water supply to bleed air from the system. The pump starts working and water enters the accumulator. The sound of water should be heard.

After the air is released, water begins to flow. Close the tap. We monitor the pressure gauge readings: the pump turns off after the pressure builds up to 2.8 Bar. Then we run water from the tap and check the operation of the pump after reducing the pressure to 1.5 Bar. The pump is working again. So, the work cycle repeats.

If you have hermetically connected the entire system, then the pump will be turned on and off in accordance with its settings. The pump connection has been successfully completed.

The installation scheme is not highly complex, but requires careful and consistent implementation of each stage of work. In order for the equipment to serve you for a long time and avoid breakdowns, pay careful attention to each stage of work. IN ideal– seek help from professionals.

High inrush current is a problem for systems with maximum power limitations. The machine can knock out, the system uninterruptible power supply go into overload mode. What should I do?

A good solution would be to use the device soft start(UPP). 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 will be required, i.e. The system must withstand a short-term power of about 5 kW. Let's say, an inverter rated at 3 kW simply will not be able to start. The moment of start will also be accompanied by a sharp increase in pressure, which actually means a water hammer on the water supply system.

We will insert a soft starter into the line supplying the pump. The device will gradually increase the voltage within a specified time (usually up to 20 seconds), 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, taking into account the cost of the pump, the decision to use a soft starter, even in the absence of an energy backup system, becomes obvious):

Let's imagine a connection diagram that can be used with both single-phase and three-phase equipment:

Are there any restrictions for using a soft starter? Yes, there are some and you should know about them:
1) The soft starter cannot be used with refrigerators. High starting current is required to stall the compressor valves.
2) Likewise for air conditioners and other equipment

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

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