Do-it-yourself pump station repair grundfos

In detail: do-it-yourself repair of the grundfos pumping station from a real master for the site my.housecope.com.

Equipment Grundfos (Grundfos) due to their reliability, performance and ease of use are widely used in all industries.

They are used in the field of housing and communal services in the construction of centralized heating lines, water supply, sewage disposal, servicing agricultural and forestry enterprises, as well as in equipping industrial complexes.

Timely maintenance of a pump or pumping station for any purpose is a guarantee of its correct operation and the durability of the system as a whole. Repairing pumps in a specialized service center, for example, in Sergiev Posad, is initially an expensive pleasure. However, if you are familiar with the device of the unit and understand the principles of its operation, it is quite possible to eliminate the malfunctions on your own.
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The Grundfos range is represented by all major categories of pumping equipment:

downhole;
sewer;
centrifugal;
circulating;
multi-stage self-priming units.

Range of pumping equipment Grundfos

Borehole pumps are used in the water supply system and in the arrangement of wells with artesian water, for filling tanks and other water distribution systems. As a rule, these are downhole installations operating in continuous or short-term mode, regulated by a pressure switch and a hydraulic tank. The product package includes three main elements - the engine, the built-in filter and the upper or lower water intake system. Products are represented by the series of equipment SP, SQ and SQE.

Video (click to play).

Let us consider the device of Sololift sewage pumps, using the example of a typical Sololift 2 WC 3 unit. The unit consists of a tank equipped with inlet / outlet openings, into which waste water enters. After the pre-cleaning provided by the filtration system and upon reaching a certain level, which is monitored by the Grundfos level sensor, the pump switches on automatically. Thus, the process of pumping out liquid into a centralized line, septic tank or other disposal tank is started. The unit is also equipped with a shredder that recycles large household waste and prevents clogging of sewer pipes. The simplest installation is capable of raising water to a height of 5-7 m and transporting it 100 m in a horizontal plane.

Monoblock centrifugal pumps of the NB series are distinguished by a one-way suction system and are used in water supply, heating, ventilation, air conditioning and irrigation systems. The torque from the engine is transmitted to the rotor impeller, and fluid enters the central part of the unit. As the blades rotate, water or another carrier of thermal energy, in the case of a heating system, is thrown towards the outer elements of the housing and redirected to the outlet pipe under the influence of centrifugal force. The pressure readings inside the system are regulated by a Grundfos level sensor.

Circulation pumps presented by the series of equipment UP, UPS, UPSD, Alpha 2 are equipped with a wet rotor and are intended mainly for completing a closed-loop heating system. Its operation is based on the centrifugal force generated by the impeller placed on the shaft.When water enters the central part of the rotating wheel from the suction pipe, it is thrown into the peripheral sections of the unit. The advantage of the equipment of this series is the automatic cooling of the rotor, which rotates directly in the pumped medium. Repair of a circular heating pump with a wet rotor is still recommended to be entrusted to professionals.

In the segment of self-priming equipment, the leader is Grundfos MQ 3-35, used in a pumping station with a diaphragm expansion tank. The circulation of water is stimulated by an increase in pressure due to the centrifugal force arising from the rotation of the impeller. When it is displaced from the peripheral compartments of the unit into the pressure pipeline, the pressure in the central part of the impeller decreases and the liquid enters the pump casing. Such models are used to increase pressure and as part of pure water supply systems (drinking or technical).

Circulation pump device Grundfos

As a rule, pump breakdown occurs suddenly and is mainly caused by incorrect operation, which also needs to be given a little attention. Installation of Sololifts, for example, and similar high-performance equipment and the first start-up should preferably be entrusted to specialists.

Before connecting a submersible or surface pump to the power grid or to a hydraulic accumulator, it is necessary to check whether there is liquid in the area of the intake device and in all pipelines of the system - with a "dry" start, the pumping station will fail with almost 100% guarantee. The volume and temperature of the water to be pumped must comply with the performance specifications and the manufacturer's recommendations.

When the pump is idle for a long time, for example, when used in a country house or in a non-residential country house, once a month it must be turned on for 15-30 minutes to prevent oxidation of moving parts.

Despite the differences in design and principle of operation, most types of pumps are characterized by the following types of problems:

lack of torque;
premature spontaneous stop of work;
increased noise level;
increased vibration;
insufficient pressure;
stop after the start.

The lack of torque, despite the fact that the unit is humming, indicates shaft oxidation as a result of prolonged downtime of the equipment or contamination of the system with foreign insoluble or coarse-grained elements in the composition of the pumped liquid. In both cases, cleaning can eliminate the malfunction; less often, measurement of the rotor shaft or the entire engine is required. If the pump does not rotate and does not make noise when switched on, it is necessary to check the parameters of the power supply and voltage.

When the pump shuts down arbitrarily shortly after starting, the problem is most likely caused by excess lime and salt mass in the space between the rotor and the starter. The problem is also solved by cleaning, which requires prior shutdown of the system and dismantling the engine.

A high noise level when switched on indicates the presence of an excess amount of air in the pipelines, which is sufficient to release with a simultaneous increase in the inlet pressure. Sololift repair is not required in this case.

The increased vibration level is due to the fact that the bearing, which the pump is equipped with in some models, has become unusable and needs to be replaced.

Pressure defects occur when the viscosity of the pumped liquid is higher than the capacity of the pumping station, which is eliminated by replacing the clogged filter. Another reason is an incorrectly implemented three-phase connection. This is also the reason for the shutdown of the equipment almost immediately after its start-up.

The device of the pumping station Grundfos

The causes of breakdowns also include uncontrollable external factors - freezing of liquid in pipelines in the event of insufficient insulation or abnormal climatic phenomena and water hammer during a "dry" start.
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Repair of a Sololift pump, as well as repair of a Grundfos pumping station for any purpose, can be done independently, having previously identified the source of the problem.

Equipment diagnostics involves several stages:

start the pumping station, evaluate the level of noise and vibration;
check the pressure indicators;
make sure that the motor does not overheat during operation;
check the presence and quality of lubrication of the nodal joints;
make sure the integrity of the structure and the absence of leaks;
inspect the box to ensure that the terminals are securely seated.

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If you are confident that the malfunctions are not caused by lime deposits and contamination, overloading or operating at maximum capacity, the pump can be disassembled. When planning to repair the Grundfos pump with your own hands, make sure that the water is drained from the pipelines and turn off the system. Disassembly begins with the junction box and a visual assessment of the components. As a rule, such an inspection makes it possible to immediately detect a burned out or worn out part. If not, we will continue to disassemble the installation.

The engine must be in an upright position during disassembly.... This will prevent the risk of oil leakage. To diagnose the trigger, an ohmmeter must be connected to the engine. This tool, when the handle is rotated, generates a voltage in the range of 200-300 V, sufficient to take readings on a resistance tester. Too high diagnostic data reaching infinity indicates an interruption of the operating phase, too low - an interturn short circuit. Self-adjustment of the operating parameters with such deviations is impossible.
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Grundfos pumps are most often used to optimize the circulation of the water supply during the heating season or in closed autonomous heating systems. They help to distribute heat evenly in the room and thus make more efficient use of energy.

Grundfos pump device.

These pumps are resistant to voltage surges and have overload protection. They are produced by a Danish company, which provides a guarantee for their quality and guarantees sufficiently high performance. These pumps can be used both at home and in industrial buildings.

However, if this equipment breaks down, the heating system will stop functioning and will remain cold until repairs are carried out.

The most common cause of pump malfunction is the formation of deposits that settle on the walls and, as a result, prevent the machine from starting. This violation can be corrected by doing the repair yourself. If you decide to purchase new equipment, it will be helpful to fix the old one. This way you can use it as a fallback.

For repairs you will need tools such as:

screwdriver;
scraper (made of wood);
hex wrench;
circle and polishing paste.

The first step is to remove all excess deposits from the shaft and rotor.

Since the main cause of pump failure is dirt build-up, the purpose of repairs is usually to clean the machine. To do this, you need to remove all unnecessary deposits from the two component parts - the shaft and the rotor. This can be done by first unscrewing the pump screws with a hex wrench and thereby disassembling the threaded connection that holds the motor and pump. Once you open it, determine how much rust has collected in it.

Depending on this, it can be removed with a cloth or scraper.In order to disassemble the washer, as well as the rotor with its impeller, it is enough to insert a thin screwdriver into the slots that are located around the support washer. You can determine for yourself how high the likelihood of new deposits forming on a given surface is. If it is smooth, there is much less chance of deposits forming. Now it can be processed with a grinding wheel.

After that, you need to inspect the stator. As a result of work, it can oxidize quite strongly, and in this case it can only be cleaned with a hammer.

For normal operation of the pump, it is necessary to polish its inner walls.

Special attention should be paid to the sensor. The dirt and rust that builds up on it over time often causes Grundfos pumps to lose their performance. As a result, their work may stop altogether. Therefore, the sensor must also be removed and cleaned of deposits. To do this, remove the cover from the control unit and disassemble the pump housing in two halves.

To remove the sensor itself, you must unscrew the screws using the wrench that comes with the pump. After loosening the screws, the sensor housing can be easily removed by hand. If this cannot be done due to settled dirt, you can pry it off with a screwdriver. Since this part is made of plastic, the manufacturer himself recommends cleaning it more carefully and using less aggressive materials. To do this, you can use a regular toothbrush.

In order for Grundfos to work again in normal mode, it is necessary to polish its inner walls. At the same time, the work can be facilitated if you use polishing tools, having previously fixed them in the drill chuck.

If a bearing is stuck in the pump, then it is necessary to disassemble it and try to turn the impeller.

In order to remove lime deposits, the system is filled with a solution of acetic acid and water, which are mixed in equal parts. Threaded connections can be sealed. This will help prevent pump leaks in the future. You can even use a bicycle tube pad for these purposes.

Sometimes the reasons for the pump stopping can be a jammed bearing, the lack of a water flow sensor, or a drop in pressure. To do this, it is not at all necessary to completely disassemble the pump in order to eliminate one of the above problems.

Try to simply switch the equipment to manual mode by removing the switch located on the junction box from the stopper and placing the handle in the middle position. This will allow the pump to run even when the tap is closed. But if this did not help him turn on, then it is necessary to disassemble the pump and try to turn the impeller. If it does not scroll, the pump cannot be repaired.

If the pump works only in manual mode, the cause of the breakdown is the flowing water sensor.

The breakdown can be eliminated by replacing the sensor itself. Sometimes the pump stops working after turning off the water due to the fact that air accumulates in it. In this case, you can lower it by turning the central screw.

After completing all these operations or when completely cleaning the pump, it must be reassembled. This is done in reverse order.If none of the above actions led to the resumption of the pump's operation, the breakdown may consist in the failure of the winding of its motor or capacitor. Such a malfunction requires replacement of spare parts, which can only be provided by a service center. Otherwise, the only way out is to replace this device. In European countries, the average service life of these pumps is about 5 years. However, the water quality in Europe is better, so the lifespan can be shortened by a year or two.

Pump manufacturers such as Grundfos produce quality pumps that are characterized by high performance and long service life. But even high-quality equipment is susceptible to breakdowns in the event of non-compliance with the norms of use or when periodic maintenance is not carried out. As a result - partial or complete cessation of the functioning of the apparatus.Grundfos pumps are usually repaired by specialized workshops, which charge a substantial fee for their services. Moreover, the problem itself is not always worth the money spent. The solution may be to repair the Grundfos pump with your own hands, which is quite possible with certain knowledge.The repair of Grundfos pumps depends largely on the type of pumping device. Depending on the type of device, the design, the most probable malfunctions and the way of their elimination differ. Among the main series of pumping devices manufactured by Grundfoss, the following stand out:

borehole pumps of the SQ, SQE, SP series;

drainage and well devices Unilift KP, cattle;

circulating devices for heating UPS, UPSD, ALPHA2, ALPHA3;

sewerage system Sololift and Sololift 2 WC 3;

Range of pumping equipment Grundfos

Each individual device implies its own peculiarities of repair and maintenance.
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Downhole tools such as SQ and SQE operate at great depths, where the bottom water can contain a high percentage of abrasives and silt. Therefore, the most common failure in such devices is contamination of the impeller and failure of the check valve. As a result, the device may not turn off after the end of work, or there is no pressure in the line. The solution to the problem will be to disassemble the pump and replace the check valve. In this case, it will not be superfluous to clean the entire working chamber.

Another common problem with the SQE series is air ingress into the system. As a result, the pressure level is disturbed, and the device turns on and off by itself. In this case, the power is turned off, the filters and the impeller are checked for contamination, then air is released from the line.

Also, a rather serious malfunction of a pumping device of the SQE type is increased vibration during operation. Such a problem can lead to too much silting of the source, which can make it unusable. Vibration occurs when the impeller is not centered. This happens when the fastenings on the housing are unevenly tightened, or the shaft bearing has become unusable. The solution is to replace the bearing and adjust the rotor inside the chamber using a ruler.

To solve any of the above problems, it is necessary to disassemble the apparatus. The procedure is carried out in the following stages:

The device is firmly clamped in a vice. It is advisable to clamp with pipe halves so as not to deform the body.
Further, VD-40 is injected into the thread area, after which you can gently turn it. The thread is often clogged with clay and sand, which greatly complicates the unwinding process.
The rotor is removed from the working chamber.

Such disassembly is sufficient for cleaning the pump chamber and replacing the main components. The motor chamber is designed in such a way that it is not possible to disassemble it. Therefore, in case of damage to the motor winding, control electronics or electrical cable, the pump must be returned for repair.

After the device is disassembled, it is necessary to clean the impeller, bearing, valves in running water, and if necessary with a brush. You should also carefully inspect the mechanical seal between the working chamber and the engine compartment. There should be no obvious damage or tears on it. After the cleaning and replacement of components is done, the device is assembled and connected to the mains.

The device of the pumping station Grundfos

Assembly is carried out upside-down. In this case, the important points are the uniform fixation of both mounts on the body, correct thread adjustment, centering of the rotor and its fixation in the socket. If the filter at the suction ports is damaged, it must be replaced to prevent further contamination.
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The Unilift KP and KRS series are designed for pumping melt water, sewage, septic tank contents, and drainage of swimming pools. At the same time, the simple design of such devices makes it easy to repair the Grundfos pump with your own hands.

Initially, drainage options are designed for difficult working conditions, therefore, breakdowns in such devices are quite rare. The main malfunctions that occur include:

decrease in pressure;
engine problems.

In the first case, there can be many reasons, but the main one is the presence of a leak. You should carefully inspect all joints for tightness, check on the outside and inside of the case wall for deformation. If no obvious problems are found, the piping, suction port and impeller should be checked for blockage. Blockages occur as a result of stagnation of dirty liquid inside the canal and its drying out. Cleaning is carried out under a strong pressure of water from a hose, and if necessary, a stiff brush is used.

In the second case, first of all, you should check the correct connection of the electric motor. Three-phase models have three working phases, and switching to another phase can solve the problem. If the problem is not resolved, the pump is disassembled further and the quality of the winding and wires is checked.

Before disassembling the device, it is imperative to turn off the device and check it for the ability to connect independently to the network. When disconnected from the mains, you can gradually remove the mesh filter of the device with a screwdriver. It is removed by uniform pressure along the entire groove at the junction with the body. Then, using a screwdriver, the case is rotated 90 degrees in the direction indicated on it and removed. This disassembly is sufficient to clean the impeller, filter and working chamber.

If after that the problem is not found, further disassembly takes place. Using a 13 key, the impeller retainer is unscrewed and it is removed. Further, the rotor nut is loosened. After completely loosening, the rotor is removed from the groove, and after it the stator can already be removed. After checking and cleaning all components, the device is assembled in reverse order. In this case, it is necessary to check the free wheel travel and the correct centering of the rotor. After complete assembly, it is necessary to connect the pump to the network and carry out a test run.

Circulation pump device Grundfos

It is possible to prevent the repair of the circulation pump, but for this it is necessary to carry out a monthly check of the device. For this, the device is turned on, and the inspector notes the following criteria:

lack of strong vibration and extraneous noise during operation;
lack of "punching" on the pipeline or the body of the apparatus;
all nuts and bolts are tightened as much as possible and do not wobble;
the engine operates in the optimal temperature range stated in the technical passport;
there are no leaks between the units of the apparatus, and at the joints with the pipeline;
all rubbing parts have grease.

Do-it-yourself pump station repair: a list of possible faults and recommendations for their elimination

The further from the city we live, the less accessible services of all kinds of service companies and repair shops become.

Even if a specialist agrees to come to a remote settlement, he will probably have to wait long enough, and the payment for services will be higher than usual.

Therefore, it is extremely important for the owner of a private house to learn how to fix all kinds of breakdowns and accidents on his own, at least in the systems responsible for the life support of the house.

These include water supply, which today is often autonomous. How to repair a pumping station with your own hands will be described in this material.

To organize the work of an ordinary home water supply system, pumping stations (NS) with a hydraulic accumulator are used. The start and stop of the pump in such systems is carried out by means of a pressure switch. This device, adjusted to a certain pressure range in the pipe, closes the contact group at its minimum value and opens at its maximum value.

So that the pump does not turn on every time, as soon as one of the residents opens the tap (frequent switching on will shorten the life of the engine), a hydraulic accumulator is connected to the water supply. From the name it is clear that this reservoir is needed to create a supply of water, but it accumulates not only it.

NS may differ in various ways:

Pump type: depending on the depth of the source, self-priming pumps (up to 8 m) and submersible are used. By the type of the pumping mechanism, most are of the centrifugal type, but among the submersible models, vibration ones are often found.
Automation type: if the water flow is carried out exclusively in a continuous mode, for example, for irrigation, instead of a pressure switch, a flow sensor is installed on the HC. It turns on the pump with the beginning of the parsing of water (reacts to the movement of the medium in the pipe) and turns it off at the end. A hydraulic accumulator is not used in such an HC. Some HC models with flow sensors and without a storage device can also be used in ordinary household water supply. They are equipped with advanced automation, which is "able" to smoothly start / stop the pump motor and change its power. In the presence of such functions, frequent switching-ons become not terrible for the unit.
Accumulator type.

Pumping station in operation

In NS, two types of accumulators are used:

balloon: water is pumped into a rubber "bulb";
membrane: the volumes for air and water are separated by an elastic membrane.

Also, drives may differ in size. It should be borne in mind that the specification indicates the volume of the entire tank, and not the volume of the water tank in it.

Autonomous water supply in the house is an important component of a comfortable stay. Well or well - which is better for a country house and a summer residence? We will help you figure it out.

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Let's mentally walk through the NN and see what can cause disruptions in its work.

After turning off the unit, it is held by a check valve installed at the beginning of the water intake pipe.