home Well and well

Choosing the best pump for wells: installation example - installation of a grundfos pump

Well construction always involves the issue of water supply. On the market, deep well pumps are presented in a wide range and it is worth figuring out in advance: which one is better to choose and how the installation is performed - installation using the example of a grundfos pump

All submersible pumps are designed to perform one main task - to supply water to a house or any other outbuilding, for irrigation, or into a backup storage tank. They are characterized by simple installation, compact dimensions and low noise level. But the main difficulty lies precisely in the choice of the type and model of the pump.

Submersible pumps for suburban wells

First of all, attention is paid to the technical parameters of the devices and their compliance with the parameters of the well. Next, the appropriate type of pump is determined, which largely depends on the quality of the water. Only after that you can go for the long-awaited acquisition, get acquainted with the instructions, installation technology, and proceed to practice.

Selection of a submersible pump in accordance with the parameters of the well

When choosing a submersible pump, a number of well parameters must be taken into account.

Water depth and level. The optimal depth from which this or that pump model can raise water is necessarily indicated in the data sheet of the unit. If the exact parameters of the well are unknown, a rope with a sinker is lowered into the casing. When the sinker touches the filter, the rope is pulled out, and the length of the dry section is measured - this is the depth to the water, the length of the wet, respectively, the height of the water column.

Scheme: submersible pump operation

Well flow rate. The parameter determines the rate of water inflow into the well. It determines the permissible pump performance, which in different models ranges from 20 to 200 l / min. It is possible to calculate the debit of a well only during pumping out of water. You can make calculations using the formula:
D = (V x T - Vsk) / T, where:
V is the pump feed rate, m3 / h;
T is the time taken to pump out, h;
Vsc is the total volume of water in the casing. Often this parameter has to be calculated additionally, recalling the school geometry and the formula for the volume of a cylinder: hxS, where h is the height, m; and S is the cross-sectional area of the casing (πхd2 / 4).

Head - this value determines whether the pump will be able to lift water from the well and supply it, while maintaining the head. To calculate the parameter, add 30 to the well height and add 10%. For example, the height of the well is 35 m, which means that the total height of the column is 65 meters + 10% = 72 m.It turns out that you need a pump model with a pressure of 80 m.

Borehole diameter. Deep-well pumps are installed directly into the wells, so the diameter of their body must correspond to the dimensions of the casing. In this case, the pump should not enter "tightly", otherwise, due to insufficient cooling, it quickly burns out. The minimum permissible parameters are indicated in the technical data sheet of the device.

Important! The pump performance should not exceed the flow rate of the well, if it is higher, the device will pump out water faster than it has time to collect and will continue to work idle, which is fraught with breakdown.

Submersible pumps: types and characteristics

Pumps are classified according to their design type: vibrating, vortex, screw and centrifugal.

In centrifugal units, the motor shaft rotates the impeller, as a result, water flows through the pipes due to centrifugal force. Before carrying out the installation, liquid is poured into the working chamber. Centrifugal pumps can be chosen for any type of well, they have a good pressure head and work with a high amount of impurities in the water (up to 180 g / m³).

Well centrifugal pumps

Vortex submersible pumps can pump water with impurities up to 40 g / m³. Their working depth is not great, about 30 m, and the maximum head is usually no more than 100 meters. The water rises due to the vortex, when the engine of the device is turned on, it is sucked into the inner channel, and then directed to the upper part of the pump. This type of unit can only be selected for a well with a low flow rate.
Screw pumps submerge to a depth of 15 meters. The dimensions of the unit are compact, and the design is simple, therefore it is cheaper than centrifugal and vortex.

Important! Vibrating pumps are insensitive to polluted or dirty water. They are used for lifting and pumping water, they have good performance and lift height, but are not suitable for wells because their vibration destroys the walls and muddies the water.

Selection of submersible pump components

Inexperienced homeowners sometimes think that choosing a pump ends everything, but for a system submerged in a well to work normally, or rather, to work at all, some components are needed.

Brass adapter that connects the pipe to the pump.
Pressure pipe - for transferring water from the well to the accumulator. It is preferable to choose a high pressure pipe (10 atm.). For pumps immersed in a well with a depth of more than 60 m and operating with a volume of more than 200 liters, a pipe (16 atm.) Is recommended.

Pump accessories

Steel cable (preferably stainless steel). On it, the pump is lowered into the well and fixed at the required height.
Clamps for the cable, with their help, the cable is fixed to the head and to the pump.
A waterproof cable for units with a 220 V power supply needs a 3-core cable, and if with 380 V, then a 4-core cable.
Heat shrink sleeve - for connecting submarine and pumping cables.
Head - closes the hole of the well and serves as a place for attaching the cable.
Pressure switch and pressure gauge. Some models are already produced with built-in automation. The relay is selected according to the maximum current value for a specific pump model.
Reducers, adapters and tees. Their number depends on the characteristics of the water supply system.
Hydroaccumulator. For a family of three to four people, it is better to choose a tank of at least 100 liters, the larger its volume, the less often the pump will turn on.

Installation of a submersible deep well pump in a well using the example of the Grundfos pump

Preparing the electric motor

Before starting the installation of the pump, it is necessary to add a special liquid grease, which fills the gaps between the bearings and reduces friction. To pour liquid into the engine, remove the protective cable strip, and disconnect the pump from the electric motor.

Gundfos pump and accessories

Unscrew the screw plug with a screwdriver, open the filler hole and pour liquid through it with a syringe. By shaking the engine, air is removed from it. Replace and tighten the plug. Assemble an electric motor with a pump.

Connecting the pump to the electric motor

The engine is neatly fixed in a horizontal position in a vice. The motor shaft is coated with a special grease, which should be included in the kit, and the pump is screwed on, capturing the edge with an open-end wrench or an adjustable wrench. If the parts are connected correctly, there is no gap between the elements.

Scheme: connecting a submersible pump for a summer well

Connecting the cable and installing the protective strip.

Before connecting the cable, you must make sure that there is no saw or moisture in the plug socket, otherwise it must be cleaned beforehand. The cable is inserted into the connector, thanks to the positioning elements, it is impossible to make a mistake in their joining, in addition, if they are connected correctly, there is not even a minimum gap at the joints.

Schematic: submersible pump motor

The cable plug is secured to the connector with four nuts. A protective strip is applied on top, its legs should easily go into the corresponding grooves on the upper edge of the pump sleeve. The bracket is screwed to the cable plug and to the input filter.

Connecting the pump to the pipeline

The submersible cable and the motor cable are sealed with a heat shrink sleeve. An adapter is used to connect the pump to the pressure pipe. If the pipe is polymeric, a crimp sleeve is selected. When connected to a pipe with a flange connection, grooves are made on the flanges in which the submersible cable and the water level tube, if any, are placed. The delivery hose is supplied and connected to the accumulator.

Deep well pump connection with pipe

Important! The power supply cable to the discharge pipe is fixed with clamps. On plastic pipes with a pitch of three meters, and on pipes with a flange connection at the top and bottom of each flange.

Well submersion and pump installation

The pump is immersed in the well to the depth indicated in the technical data sheet of this model, and is fixed in a vertical position. Adequate cooling of the motor ensures sufficient clearance between the pump casing and the borehole wall.
After submersion, the cable is fixed on the bracket of the casing head.

Electrical connection to the pump

Before connecting, you must familiarize yourself with the technical characteristics of a particular device, all data on power supply, maximum current and power factor are taken from the device's passport. The protection relay, through which the unit will be connected, must be triggered both in the event of an emergency alternating current and during a constant ripple.

Scheme: connection system of a deep pump

Such devices are specially marked. Most models of Grundfos pumps are available with a built-in thermal relay, according to
they need additional protection for this.

Electric motors in Gundfos units are equipped with a built-in starter and are connected to the mains through a switch. Start and stop is carried out via a pressure switch. After connecting and checking, the pump is carefully lowered into the well. They fix the cable on the head, start and check the performance of the entire system.