Start relay for a refrigerator: frequent breakdowns and methods for repairing the start protection relay

For a three-phase motor, the presence of a starting winding is an unnecessary element. Consuming 380 volts, it is connected directly to the network, the stator coils are phased in a certain way. Requires starting from a 230 volt network - craftsmen begin to use chemicals. Star and delta circuits appear, using a capacitor that provides a voltage shift of 90 degrees in an arbitrary winding relative to the remaining two. The first one acts as a starting one; the capacitor should turn off when the engine picks up speed. In fact, a three-phase motor turns into a two-phase one. Of course, you can make a power supply that produces three sinusoids, artificially shifted 120 degrees relative to each other. The start-up protection relay of the refrigerator echoes the operating principles of asynchronous motors and serves to implement the functions implied by the name.

Refrigerator compressor device

A fundamental physical rule also applies in everyday life: heat is transferred from a body with a higher temperature to a body that is less heated.
In order for the reverse process to occur and cold to be created in a household appliance, external energy must be applied in the form of mechanical work. This is exactly how refrigeration systems operate. Electricity powers a special device that creates pressure and compresses the refrigerant gas to convert it into a liquid state. Such a part is the compressor, which is often called the “heart of the refrigerator.” After all, if it stops working normally, the process of generating cold is impossible. In addition to compression, other types of installations are known (absorption, thermoelectric), but they cannot be found in household solutions for the home.

By design, compressors are most often an electric motor driving a single-cylinder piston pump with a valve mechanism. Less common are linear-type installations, where there are no rotating parts, and the pump piston vibrates from the reciprocating movements of the electromagnetic coil core. However, these devices are not so common; they are practically not found on older models of refrigerators.

Inverter compressors are considered the most advanced type of technology, having a number of noticeable advantages over previous models. They are produced today by leading companies in the industry:

LG;
Liebherr;
"Bosch"
"Indesit".

However, the downside is their excessive complexity, which does not allow diagnosing and repairing the system at home with your own hands.

When a refrigerator with an inverter compressor breaks down, you should not try to do anything with it yourself; contact qualified service technicians. If the installation is of a conventional type with direct power supply from 220V, there is a chance to start a jammed refrigerator compressor without resorting to outside help. Traditionally, domestic brands of equipment (Atlant, Sviyaga) are more suitable for DIY repairs.

Where is the compressor located?

The compressor engine, together with the piston pump, valve mechanism and freon receivers, are usually installed on damping springs inside a hermetically welded metal casing. This part is usually painted black for better heat transfer and looks like a round tank with tubes coming out of it. Place it in the back wall of the refrigerator on a metal frame near the condenser (a coil of tubes that dissipates excess heat).

The pressure inside the sealed compressor housing during normal operation is 10 atmospheres. Power is supplied to the motor through contacts on the outer wall of the tank.

Checking the compressor for functionality

The result of normal operation of the compressor is the creation of the required refrigerant pressure in the pipe system. This indicator varies for different models, but it is fundamentally believed that if the output pressure is less than 4 atmospheres, the device is unsuitable for operation.

If the purpose of the repair is an attempt to restore normal operation of the refrigerator, the condition of the compressor will have to be assessed by indirect signs (noise, vibration). According to reviews from experts, the two most common breakdowns are:

malfunction of electrical equipment, including failure of the start-up relay;
jamming of the mechanical part of the compressor (the rotor of its engine or the piston in the pump cylinder).

The system is checked separately for each of these problems to understand which part requires repair or replacement. To do this, you will need to directly start the refrigerator compressor without a relay.

Operating principle of the starting protection relay

The starting coil must be turned off when the speed is up. At the moment of start, the windings consume a large current, the effect allows you to track the moment of recommutation. The refrigerator start relay performs protective functions (not always). The option is implemented by heating the sensitive element with electric current. The threshold is exceeded - the circuit breaks, regardless of whether the desired refrigerator mode has been reached according to the thermostat readings or not. Two schemes for the operation of the starting relay have been invented (at the same time it can be protective):

"Tablets" work on the basis of a material that expands by heat. Initially, the working element is cold, the starting winding consumes current, ensuring a smooth start of the asynchronous motor. Gradually, the temperature of the tablet rises, causing the contact to open, and the working coil remains switched on. We believe that to maintain the mode, a mechanism is installed inside the relay to prevent the tablet from cooling. Operating winding choke, heating element. If a button relay breaks, you can often hear the rustle of scattered powder inside, changing the position of the device body.
Induction relays are based on the action of electromagnets. When starting, the current is high and due to this the core presses the contacts of the starting coil. Over time, engine consumption drops. As a result, the current will no longer balance the spring, and the contacts of the starting coil open. Please note: it is important to orient the relay in space correctly. Often the core falls, carried away by the force of gravity. But testing such elements is much simpler: turn from side to side so that the contacts of the starting relay change the resistance from zero to infinity.

The tablets often come with thermal relays on a bimetallic plate in the same housing. The current of the working coil passes through it. As soon as the value exceeds the response threshold, the contacts open, stopping the compressor. The bimetallic type refrigerator relay circuit is based on heating the sensitive element.

There is nothing complicated about it! The two plates are welded tightly to each other. The coefficient of expansion of metals in them is different. When heating occurs, the double plate bends towards the material that elongates less. It becomes possible for the relay to operate. This scheme is often used in household appliances.

Induction relays often use a heating coil. There is already one material here. But it heats (!) the bimetallic plate. The current of the working coil passes through the spiral. If the amperage is too high, the bimetallic strip breaks the contacts. The inductive start-up relay has the following types of faults:

the spiral has burned out, in this case the contacts will not ring in any position;
the core is jammed, the engine does not start, or the engine stalls after 5 - 10 seconds;
The operating mode of the plate is disrupted, the refrigerator turns off even in normal mode.

We would like to draw your attention: thermal protection is completely emergency. In normal operation, the relay should not operate. At the same time, the starting function accompanies the refrigerator during the operating period. The switching process is accompanied by a slight click. We often hear the start-up relay in the refrigerator when the appliance is running.

The start-up relay resembles a tablet or an indeterminate shape in appearance. This is such a small element located directly next to the black barrel-shaped compressor housing. Have you ever wondered why this soot color was chosen to paint the heart of the refrigerator?

The answer is simple: black absorbs heat, but also radiates well. In which direction the process moves determines the direction of the temperature difference between the compressor and the environment. When the motor is hot, the black housing gives off heat to the air. In addition, there is a fan nearby that creates forced cooling of the compressor.

Read more: Cast iron bathtub repair: enamel, acrylic

Switching diagram of the refrigerator start-up relay:

Phase 220 V.
Earth.

Starting winding of an asynchronous compressor motor.
Working winding of an asynchronous compressor motor.
Earth.

You can usually find out what is connected where and by the color of the wires. In any case, repairs should be carried out carefully. It’s easier to find out the compressor ground if you scrape a little paint off the housing and ring the three contacts. But this method is left for last when the others have not helped.

DXR induction start-up protection relays are mounted on a fixed frame and work in tandem with DXM compressors. The designation may be followed by a number that is the same for both devices. The difference in designs is in the operating voltage and operating and releasing currents. To speed up the breaking of the circuit when overheated, a magnet is located behind the bimetallic plate.

The induction relay for the RTP refrigerator compressor differs in that it can also be located on a wire. Doesn't have to be attached to the frame. The work is carried out with compressors DXM 3 and 5. The difference from DXR is a slightly lower operating current. This will better protect the compressor. The release current is the same. Craftsmen use refrigeration compressors to manufacture high-pressure apparatuses and receivers. Tires are inflated and pneumatic equipment is used.

Before you buy a relay for your refrigerator, make sure that the product matches the type of compressor. The element must then be installed correctly. It is better to take exactly the brand that was available before the repair. If the relay of the Biryusa refrigerator is equipped with the RTK type, it is better to take this, despite the fact that both RTP and DXR are also suitable for the DXM engine. Lookup tables can help determine device compatibility. Indicate the necessary technical information.

Starting an asynchronous motor with a single-phase 230 volt network

Voltage 380 volts - three phases of 230 volts each, both cases consider the effective value. Causing a similar thermal effect on passive resistance. The alternating voltage changes continuously, the figure is averaged over time. The result is called the effective (effective) value of the quantity.

For an induction motor to operate correctly, the stator field must rotate. It is easy to ensure (proven by Nikola Tesla): apply the corresponding phases to three windings. Vector addition of fields occurs. The resulting vector rotates smoothly, dragging the rotor. The efficiency of three-phase motors on a 380 V network is the maximum among other varieties and types of inclusions. In industry, voltages that are unusual for residential buildings are used. Can a tenant get 380V? Hypothetically, yes. A professional electrician will find three phases shifted relative to each other at the desired angle (120 degrees).

Phase one. Rotation of the field is fundamentally impossible. Motion is obtained by adding at least two vectors. You have to use the services of a capacitor that shifts the voltage by 90 degrees. In fact, with a star or triangle circuit, one winding acts as a starting winding and causes the field to rotate. Subsequently, the value changes linearly, since the engine has gained speed, the inertia is enough to maintain rotational motion. The alternating field will rhythmically push the rotor in the desired direction. The smoothness is inferior to the resulting addition of three vectors; the functioning of home appliances is sufficient.

What does the starting winding do? The engine will not enter operating mode, creates a second vector, which, to a first approximation, allows us to consider the field inside the engine to be rotating. It’s enough to move the uneven circle and spin the rotor. The speed is up, the starting coil must be turned off, there is minimal use, a lot of energy is wasted, reducing the efficiency of the device.

Mains voltage

To find out the voltage in your home electrical system, the easiest way is to use a multimeter, measuring and recording the results obtained over different periods of time. The more accurately you find out what the minimum and maximum voltage is in your apartment or house, in addition, measure how intensively it changes, whether there are sudden jumps or whether the changes are quite smooth, the more suitable a stabilizer model you can choose.

Why you shouldn’t hesitate to replace a faulty relay

Of course, folk “craftsmen” have already learned how to start a refrigerator without a start-up relay by connecting the contacts directly. However, experienced craftsmen categorically advise against doing this. In the refrigerator, each part carries its own payload. And the exclusion of any component from the electrical circuit is fraught with overloading of the mechanisms, overheating of the engine and, at best, breakdown of the motor-compressor, and at worst, a fire. Actually, the name of the part itself suggests that it is necessary for the correct start-up of the unit. And the protective part of the relay just saves the equipment from excessive thermal load. Simply put - from overheating.

So don't put off replacing it. When choosing, be guided by the brand and characteristics of the spare part removed from your refrigerator. Ideally, you should purchase exactly the same modification of the part and connect it to the refrigeration unit in the same way.

We hope you found our instructions for diagnosing and troubleshooting useful.

Dismantling and replacing the compressor

If a problem is detected, the part should be replaced. To do this, you can use the services of a specialist or arrange all the repair work yourself. This is done when the winding becomes unusable or any other component breaks down.

We hope that there are no dark spots or uncertainties left for you in the question of how to check the refrigerator compressor.

It is also necessary to fill the compressor with oil after repair work. This is a necessary condition for the normal operation of bearings and to prevent rapid wear of parts as a result of friction.

Even if you are not able to completely eliminate all the breakdowns yourself, you will receive accurate information about the faulty parts.

All the steps described above will help you replace the compressor in the refrigerator yourself. But if for some reason some points remain unclear, then you can use the video presented, where all the manipulations are discussed in detail.

Connection according to instructions

The electric motor used to drive the pump is equipped with a double excitation winding. To start the equipment, increased power is required, so the motor design includes a starting winding. After starting work, the power is automatically switched to the working winding, which reduces energy consumption. Additional relays that maintain the required temperature background are located upstream of the compressor housing.

To connect the refrigerator compressor according to the factory circuit, you will need to use a cable equipped with a plug socket. The wires are connected to the terminals on the relay body; since alternating current is used for power, the polarity of the connection is not taken into account. To ensure reliable contact, terminals are installed on the cables; the type of elements depends on the modification and manufacturer of the relay. After plugging the plug into the socket, the motor should start; if the start is unsuccessful, then you should start checking the components in the power circuit.

When and why is such a connection needed?

The refrigeration compressor is a piston machine driven by an AC commutator electric motor. The drive and discharge mechanism are mounted on a frame inside a metal closed housing. The casing is attached to the refrigerator body with bolts through supports with rubber damping inserts. A special starting relay is installed on the housing, into which the winding contacts are routed. The relay works in conjunction with the thermostat to maintain the set temperature in the freezer compartment of the refrigeration unit.

The connection is directly used to check the condition of the windings of an electric motor without taking into account the condition of the relay, thermostat and connecting wiring. Before starting testing, you should check the operability of the windings, as well as the absence of breakdown of electrical circuits on the compressor housing.

How to connect the refrigerator compressor relay?

To connect the refrigerator compressor relay, you need to follow a few simple steps. This uses a windshield washer hose. Finding it won't be difficult. It is available in almost any store that sells spare parts for cars.

Regarding the operation of the device, it is important to monitor the oil level. This will avoid overheating

In this case, the duration of operation of the device should not exceed forty-five minutes. Otherwise, it may quickly fail.

This device is electric. Therefore, when using it, it is necessary to observe safety precautions. Before starting operation, the quality of the wire insulation must be checked. In this case, only special material is used. Hands must be dry when using the device.

It is also worth noting that you should not hope for a long service life of such a device. Since no one can provide guarantees for this. This must be taken into account, so sometimes it is better to purchase a new compressor than to use a homemade one.

CONCLUSIONS

To summarize: if you have problems with voltage in your apartment, house or country house, you notice changes - surges or drops, problems in the operation of electrical equipment or lamps - installing a voltage stabilizer for the refrigerator is simply necessary.

In this case, it is best to choose inexpensive single-phase relay stabilizers with a power of 1500-2000 VA, or calculate separately for a specific refrigerator model. In addition to what is indicated in the Resanta article, I also advise you to take a closer look at the ELITECH ASN 2000 or QUATTRO ELEMENTI Stabilia 2000 , which have good reviews and are deservedly chosen by consumers.

I also ask that if you have experience in selecting, purchasing and using stabilizers for refrigerators, be sure to write about it in the comments to the article, even if it is not very successful. In addition, as usual, any opinions, criticism, questions are welcome - I will try to answer everyone promptly!

Source

Main symptoms of a malfunction

There are two main “symptoms” of a relay failure. This is an undercharge or overcharge of the battery. Also, a malfunction of a part can be determined by the dim glow of the headlights or by a change in their brightness when the engine speed increases.

If undercharged, the car will start with great difficulty. However, the manifestation of this “symptom” may not be related to the generator. Therefore, first of all, you should make sure that the battery is in good condition.

If the battery is overcharged, there is no doubt that the problem lies in the damaged relay. There are other possible causes of overcharging, but they are extremely rare. Overcharging may cause the battery to boil over. This can be determined by the decrease in the amount of electrolyte in the jars and the appearance of a white coating on the battery.

If you suspect that the battery is overcharged or undercharged, you should diagnose the generator.

Causes of failure

Often the cause of failure is due to natural wear and tear of certain elements of this part or generally incorrect operation of the equipment.

There are 2 main signs of malfunction of this particular refrigerator element:

The motor of the device turns on, but after a short time it turns off, or does not start at all. It is likely that the contacts in the winding have shorted out.
The engine does not start, but current flows to it. A possible reason is a weakened spring, which requires prompt replacement of the starting relay.

Read more: Repairing wooden floors in an apartment with your own hands, price

Refrigerator relay replacement

Replacing the relay in the refrigerator is carried out at a service center or independently at home. To carry out the work, a tester and a screwdriver are required to dismantle the element.

Removing the relay

You can remove the device yourself, taking into account the following points:

Before carrying out any work, the device must be disconnected from the network, after which you need to wait some time to de-energize the entire system.
The RTP type can be removed by simply disconnecting the contacts. A relay on a refrigerator for starting an engine is often installed without insulating the contacts, which causes the appearance of oxide on the contacts. Therefore, problems with dismantling may arise.
You can replace the device depending on how it is attached. Rivets, screws and latches are used. You can unscrew the screws with a screwdriver; the latches are pressed out.

The type of mounting method used largely depends on the refrigerator model. You can replace the mechanism yourself only by selecting a relay taking into account the characteristics of the equipment.

Relay selection

After checking the mechanism, you can often find that it needs to be completely replaced. The refrigerator starting relay is selected taking into account the following points:

Technical characteristics specified in the operating instructions.
According to the parameters of the installed engine.
The mechanism is sold at different prices: from 500 to 3000 rubles.

Manufacturers indicate what mechanisms should be installed.

Relay connection

You can connect to the compressor yourself. The work is carried out according to the following scheme:

disconnect the electrical appliance from the network;
wait a few minutes for the equipment to completely de-energize;
unfasten the water supply hose from the back wall and move it away so as not to accidentally damage it;
Unscrew the fasteners securing the protective panel and put them aside;
remove the old start relay; if it is not there, find the location on the compressor;
connect the connector to the new device;
insert into place;
connect the wires according to the markings;
secure the trigger mechanism with screws and latches;
put the back panel in place, screw it on;
attach the water supply hose, secure;
plug into the electrical network for testing.

After this, a working device is installed. A complex connection diagram involves connecting additional wires, through which the device is controlled.

If the refrigerator does not operate stably and the relay has been checked, there is a possibility of failure of one of the important components. The low cost of the mechanism allows you to replace it quickly and without significant costs. When installing a new device, you need to be careful, as incorrect connection can lead to malfunction.

Background

The service department received a standard request: the Ariston refrigerator needs to be repaired, the reason is that it has stopped freezing. Diagnostics showed that the temperature sensor was to blame for the problem. The replacement of the faulty element was successful, but after approximately 2 weeks, an application was again received from the same Client.

The repairman was ready to repair the refrigerator under warranty, but a check of the unit revealed that this time the sensor was normal, but the compressor was faulty. The customer decided to completely replace the unit (we admit, this procedure is not cheap), but after a month and a half he asked for help again. It became clear that the problem was not with the unit, but then what? Such frequent power surges require the presence of powerful external forces.

In a conversation with the master, the Client admitted that there was construction going on in the courtyard of his house, due to which the light in the apartment was constantly flickering. When he once again noticed that the voltage began to “jump,” he disconnected the refrigerator from the network (after all, it had just recently been repaired), and reconnected it about 2 minutes later. Moreover, he carried out such manipulations regularly for good purposes.

The picture has finally become clearer. The long-suffering refrigerator, despite the admonitions of the technician and the recommendations specified in the instructions, was connected to the network immediately after being disconnected. A ten-minute pause would have saved the unit from breakdown.

The compressor restart delay is necessary to stabilize the pressure in all hydraulic components of the unit. This requirement is due to the inertia of the system and common sense.

Operating principle of the start relay

Despite the large number of manufacturers of components for refrigerators, the operating scheme and design of starting relays are almost the same. Having understood the principle of their operation, you can independently find and fix the problem.

Device diagram and connection to the compressor

The relay circuitry has two inputs from the power supply and three outputs to the compressor. One input (conditionally zero) passes directly, and the other (conditionally phase) inside the device is split into two:

the first passes directly to the working winding;
the second passes through the disconnecting contacts to the starting winding.

If the relay does not have a seat, then when connecting to the compressor you must not make a mistake with the order of connecting the contacts. Methods common on the Internet for determining winding types by measuring resistance are not correct in general, since some motors have the same resistance of the starting and running windings.

The electrical circuit of the start-up relay may have minor modifications depending on the manufacturer. For example, the protective block can be placed on the core, which is located below in the figure

Therefore, it is necessary to find documentation or disassemble the compressor to understand the location of the feed-through contacts. This can also be done if there are symbolic identifiers near the outputs:

“S” – starting winding;
“R” – working winding;
“C” – general output.

The relays differ in the way they are mounted on the frame of the refrigerator or on the compressor. They also have their own current characteristics, so when replacing it is necessary to select a completely identical device, or better yet, the same model.

Closing contacts using an induction coil

An electromagnetic starting relay works by closing a contact to pass current through the starting winding. The main operating element of the device is a solenoid coil connected in series with the main winding of the motor.

At the moment the compressor starts, with the rotor static, a large starting current passes through the solenoid. As a result, a magnetic field is created that moves the core (armature) with a conductive strip installed on it, which closes the contact of the starting winding. The rotor begins to accelerate.

As the rotor speed increases, the amount of current passing through the coil decreases, as a result of which the magnetic field voltage decreases. Under the action of a compensating spring or gravity, the core returns to its original position and the contact opens.

On the cover of the relay with the induction coil there is an “up” arrow, which indicates the correct position of the device in space. If it is placed differently, then the contacts will not open under the influence of gravity

The compressor motor continues to operate in the mode of maintaining rotor rotation, passing current through the working winding. The next time the relay will work only after the rotor stops.

Regulation of current supply with a posistor

Relays produced for modern refrigerators often use a posistor - a type of thermal resistor. For this device, there is a temperature range below which it passes current with little resistance, and above which the resistance increases sharply and the circuit opens.

In a starting relay, a posistor is integrated into the circuit leading to the starting winding. At room temperature, the resistance of this element is insignificant, so when the compressor starts operating, current flows unhindered.

Due to the presence of resistance, the posistor gradually heats up and when a certain temperature is reached, the circuit opens. It cools down only after the current supply to the compressor is stopped and starts skipping again when the engine is turned on again.

The posistor has the shape of a low cylinder, which is why professional electricians often call it a “tablet”.

Current protection device

Asynchronous motors provide several types of protection against current consumption exceeding a specified value. This occurs during a short circuit in the operating circuits or when the components overheat due to fan failure (thermal protection is triggered). At the same time, a situation cannot be excluded when the engine operates for some time (on the order of several seconds) in the mode of limiting currents that exceed the norm by 2-5 times. As a rule, this happens when the load on the shaft increases sharply due to the phenomenon of jamming.

At the same time, the current consumed from the network also increases, but its value does not reach the short-circuit values. As a result, the circuit breaker does not have time to turn off the power circuit. The thermal relay also does not work, since the temperature of its contact does not have time to change in such a short time. The surest way to protect the motor from overload in this case is to use a current protection device installed in the following places:

In the internal cavity of the compressor.
In a separate building.
Inside the PR itself.

In the latter case, a device is obtained that combines the functions of connecting the starting circuit and current protection. Experts call it a start-up protection relay (PPR).

The operation of this device is based on 3 principles:

as the current increases, conductive materials heat up;
as a result, expansion of the metal is observed;
For different types of metal materials, the expansion coefficient is different.

All these principles are satisfied by structures made in the form of bimetallic plates welded together with excellent CTE (coefficient of thermal expansion).

Due to the difference in these indicators, when heated by the current flowing through it, such a plate begins to bend; moreover, one of its ends remains in a fixed position. At the same time, the second one is slightly deflected and opens the working contact. Each type of bimetallic plate is designed for a certain current, so when replacing a PZR, you will need to make sure that it is compatible with a non-working device.

Checking the compressor's performance

You can check the motor using a test device switched to resistance measurement mode. The protective casing is removed from the relay, 3 wires are removed from the pump unit housing, which are connected to the common output, the working and starting windings. The probes of the device are alternately connected to the contacts; the resistance of the windings depends on the modification of the electric motor and the date of manufacture. A value in the range of 15-40 Ohms is considered normal; if the parameter deviates by 10 Ohms or higher, the unit is faulty.

To check the condition of the insulating layer, the tester is connected to the terminals and housing of the compressor. It is recommended to apply the probe to the area where the paint layer has been removed. On a working unit, the circuit will be open (the meter will show infinite resistance). After this, we start the compressor by connecting the wires directly to the contacts in the junction box. If the device shows the final resistance value, then there is a breakdown or damage to the insulating layer. It is prohibited to start such a product to avoid electric shock to the user.

Basic parameters of capacitors

The capacitance of a capacitor characterizes the energy that the capacitor is capable of accumulating, as well as the current that it is capable of passing through itself. Measured in Farads with a multiplying prefix (nano, micro, etc.).

The most commonly used values for run and start capacitors range from 1 μF to 100 μF.

The rated voltage of a capacitor is the voltage at which the capacitor is able to operate reliably and for a long time, maintaining its parameters.

Well-known capacitor manufacturers indicate on its body the voltage and the corresponding guaranteed operating time in hours, for example:

400 V - 10,000 hours
450 V - 5000 hours
500 V - 1000 hours

Video of replacing a relay in a refrigerator

In case of malfunction and suspected malfunction of the start-up relay, immediate replacement of the start-up relay of the refrigerator

, otherwise the consequences may be irreversible, and the compressor will have to be completely replaced.
However, some sources claim that the start-up relay can be repaired. This is absolutely not true. To restore the refrigerator to normal operation, only replacing the start-up relay
.

The main signs of a problem with the start relay

Uncharacteristic sounds occur when the compressor is turned on: rattling, clicking, creaking, strong hum.

The motor-compressor suddenly turns off immediately after starting or does not turn on at all.

The start relay switches on very frequently, either starting or stopping the compressor at varying intervals.

If you begin to notice that such signs are occurring, you need to call a technician to your home as soon as possible and carry out diagnostics to determine the exact cause, and then repair the refrigerator inexpensively.

Cost of replacing the start protection relay

Replacing the start-protection relay

- the work is not particularly expensive. Other repairs associated with eliminating malfunctions caused by the breakdown of this component are much more expensive. A faulty relay can cause a more serious malfunction, in particular, damage the compressor. Replacing a compressor will cost several times more, so at the first sign of a relay failure, you must contact service for help. Thus, you can save a lot and protect your equipment from irreversible consequences.

Speaking about the cost of the master’s services, everything is individual and it depends on several points:

Makes and models of your faulty refrigerator.

New component prices.

Difficulty in handling, because some models require disassembling the refrigeration unit housing.

The year of manufacture of the household appliance and the period of its use (for models older than 5 years, it is difficult to find a suitable part).

The final price of the work will be known only after the diagnosis has been carried out. Our specialist will definitely tell you the cost of the upcoming repair and begin replacing the start relay, if you agree. Upon completion of all procedures, the technician will start the refrigerator in test mode and issue a warranty card.

How to replace a refrigerator relay

To visualize and detect the relay, you need to turn the refrigerator around the back wall. The relay is located on the compressor and has a protective plastic box. To replace it, you need to remove it, first disconnecting the wires and terminals. Check contact groups for charring. If necessary, clean them with a sharp knife and remove excess. After this, replace the start relay, put the protective cover in place and connect all the wires in their places. Replace the refrigerator relay yourself

It’s not at all difficult, however, you need to know the basics of using the tool, and most importantly, correctly and accurately diagnose that this particular component is faulty. Watch the video for details.

Refrigerator engine diagnostics

If you still decide to repair and check the refrigerator compressor yourself, then first carry out a complete preliminary diagnosis of the main engine. To do this, perform the following steps:

Make sure what temperature the condensate has. Since in this case, insufficient injection of cooling gas may occur.
If this is not the case, then use a multimeter. This will help ensure that the housing does not break through.
If this is not the problem, then further inspection is carried out. To do this, the contact wiring is disconnected. Then the motor tubes are cut. Unscrew the housing and remove the relay. After which you can measure the resistance level between the two contacts.

A broken or burned wire in one of the windings is the most common cause of breakdown of the entire compressor unit.

Triggering of the protective relay

Often, a protective relay is triggered when the current in the motor winding circuit increases. This is necessary to protect the motor winding from combustion. Such single relay operations do not affect the operation of the refrigerator or the cooling of food.

In the event of a malfunction, the protective relay starts to operate too often. This can be signaled by characteristic clicks that are heard when the contacts open.

Depending on how often and for what reason the relays are triggered, the motor may either turn on periodically and cool the chamber, or not work at all. You can verify the frequent operation of the protective relay using a test light. The ends of the light bulb wire should be connected to the protective relay and fixed in the operating position. If the motor-compressor switches off due to the relay being activated, the indicator light will light up. If the motor-compressor turns off due to a faulty thermostat, the light will not light up.

The reason for the frequent activation of the start-up relay may be insufficient voltage in the network, weak fastening of the part itself, or its malfunction. If the part is in working order, the protective relay can very often be triggered due to jamming in the compressor or breakage of the starting winding. In this case, the engine does not turn on at all and the refrigeration unit does not function.

It is not recommended to connect the motor-compressor directly to the network during testing.

Troubleshooting

Taking into account the fact that the number of elements in the relay is insignificant, their serviceability can be checked using the method of sequential elimination. To do this, just stock up on a flat-head screwdriver and a multimeter. During repairs, it is important to pay attention to the following points.

Purely structurally, e/m relays are devices with contacts that are open in the normal state. The posistor version of the switching device has contacts that are initially closed. In the first case, when the motor starts, no current flows through the starting circuit, but in the second case, vice versa.

If a compressor that is known to be working does not start, this means that voltage is not supplied to the starting coil. The reason in this case is as follows:

Triggering of the current protection relay.
A break in the circuit through which current should initially flow.
PTC fault.

Let's look at each of these problems in more detail.

Malfunctions in the current protection relay (RZT)

In a situation where the refrigerator turns on for a while (5-20 seconds) and then turns off, this means that the relay switch has tripped.

The reasons for its disabling are listed below:

operation is associated with damage to the working winding (the relay is triggered by overcurrent);
the starting relay does not open the contacts in the starting circuit;
The current relay is faulty and is triggered by minimal heating.

If, when testing with a multimeter, a break in the power supply circuit of the windings is detected, most likely the protection relay itself is faulty. This is usually caused by poor contact in the bimetallic strip. The easiest way out is to replace the damaged device with a new one.

Problems in the starting circuit

Faults of this type are detected using a conventional multimeter, with which you will need to test the following electrical circuits:

If a break is detected in the area up to the working winding, it is necessary to check the serviceability of the PZR.
In this case, special attention is paid to sticking or oxidation of its contacts.
If there is no continuity in the area up to the start coil, in addition to an open circuit, malfunctions of the PZR or lack of contact in the connecting strips are possible.

In a device with an induction coil, to restore contact, you will have to manually lift the contact bar with the return spring.

PTC fault

To make sure the posistor is working, you will need to check its resistance in various states. To do this, wait until it has completely cooled down and test its circuit with a multimeter or similar device. If the tester shows a complete absence of current or a significant resistance value, the posistor should be replaced with a new sample.

To check the shutdown mode, you need to connect some load to the posistor (for example, a 100-watt incandescent lamp). To do this, you will need a plug with terminals connected to the input circuit of the device. The wires coming from the lamp are connected to a connector, the contacts of which are connected to the power supply zero and the phase end of the starting winding.

When turned on, current begins to flow throughout the protective circuit and through the lamp and it lights up. Since its value is significantly lower than when starting the engine, the protective element heats up for a very long time (for the selected lamp this period will be about 20-40 seconds).

If over time the incandescent light bulb goes out, then you can be sure that the element being tested is in good working order. If nothing happens and the circuit does not break over time, this means that the posistor is faulty. In this situation, the easiest way is to purchase a new device.

Problems with contacts

There are two known causes of the malfunction in question. This is the absence of current in the circuit with seemingly closed contacts and their sticking due to loss of elasticity of the plates. The first case is typical for a situation where the contact heels are heavily oxidized. The problem can be solved by cleaning them using sandpaper. Another reason is the deformation of the clamping bar itself. In this case, it will be necessary to restore its shape to ensure normal pressure and contact.

A more complex malfunction is the sticking of the bar with the pin, which is triggered when current flows through the solenoid and does not come off when it is turned off. To resolve this problem, you will need to clean the elements that control the switching unit.

Compressor malfunction: symptoms

Quite often, refrigeration equipment breakdowns occur due to a compressor malfunction. Most often, this problem can be recognized by the following signs:

noticeable blocks of ice freeze on the walls of the refrigerator (this often happens in the absence of a No Frost system);
When the compressor is running, a loud sound is heard, but the refrigerator does not freeze;
When the refrigerator is turned on, there is strong vibration;
the compressor does not turn off;
The refrigerator freezes food.

No Frost System

In order to deal with the problem, it is necessary to consider the signs of failure in more detail.

Table 2. Signs of compressor failure

Breaking	Causes
The compressor works, but does not freeze	The cause of the problem is often a refrigerant leak due to improper transportation of the unit. In addition, this occurs in the event of a malfunction of the heating element.

If the refrigerator has an inverter-type compressor, then after reaching the desired temperature, it still functions, but only at minimum speed.

There are other reasons for the malfunction:

The compressor does not stop working	This problem occurs for the following reasons: refrigerant leak; depressurization of the capillary pipeline, which caused a blockage in the system; The rubber seal has dried out, the temperature inside the unit has increased, which is why the motor starts working without stopping.
The compressor hums but does not function	Extraneous noise during compressor operation often occurs when there are bolts that must be removed after transportation. However, this only applies to new devices.

pipe deformation;
thermostat failure.
Refrigerator compressor turns on and then immediately stops The following causes of malfunctions are identified:
breakdown of the starting relay, which is responsible for starting the engine;
break of internal winding;
The start relay winding is broken and the compressor overheats.

Solution

To protect the refrigerator from power surges, certain rules must be followed:

use of special units;
compliance with the basic rules for operating electrical appliances;
repair of all sockets, plugs and other electrical components;
To turn on the refrigerator, you should use an individual outlet, which cannot be connected to other electrical appliances.

The optimal solution to the problem would be to install special units that will protect equipment from power surges. These include:

Voltage control relay. One device is used to protect all equipment in the house. It independently turns off the power when the reading changes below or above the normal limit. The relay turns on the electricity after the voltage normalizes. Additionally, there is a pause. Its duration can be set independently or set automatically.

Voltage control relay

Group voltage control relays. Consists of several voltage control relays. A separate relay is used for the refrigerator. One turns on with a certain delay, while the rest of the equipment in the house can turn on faster. The advantage of this method is its high reliability. The disadvantage is the high price and the need for space in the electrical panel.
Surge Protectors. It is a fairly expensive piece of equipment, so it is recommended to choose it if power surges frequently occur or if expensive equipment is installed in the house.

Voltage regulator

Network filters. Protects against minor voltage surges. Can only be used for one device. The use of such a filter requires high-quality grounding. If you do not connect it correctly, the surge protector will only act as an extension cord.

Network filters

These are the main methods of protecting your refrigerator from power surges. Simple ones can be implemented independently. Installing complex devices may require the assistance of a professional.

Operating principle of the start relay

Despite the large number of patented products from various manufacturers, the operation schemes of refrigerators and the operating principles of starting relays are almost the same. Having understood the principle of their operation, you can independently find and fix the problem.

Device diagram and connection to the compressor

The relay circuitry has two inputs from the power supply and three outputs to the compressor. One input (conditionally zero) passes directly.

The other input (conditionally – phase) inside the device is split into two:

the first passes directly to the working winding;
the second passes through the disconnecting contacts to the starting winding.

The electrical circuit of the start-up relay may have minor modifications depending on the manufacturer. The figure shows a diagram of the connection of this device in the Orsk refrigerator

Therefore, it is necessary to find documentation or disassemble the refrigerator compressor to understand the location of the feed-through contacts.

This can also be done if there are symbolic identifiers near the outputs:

“S” – starting winding;
“R” – working winding;
“C” – general output.

Closing contacts using an induction coil

The compressor motor continues to operate in the mode of maintaining rotor rotation, passing current through the working winding. The next time the relay will work only after the rotor stops.

Starting the engine

At their core, the drive motors used in compressors are single-phase asynchronous motors (IM) equipped with a starting winding. The basis of their design is a stationary stator with a set of coils and a rotating rotor. The moving part of the engine, or rotor, is a hollow cylinder made of aluminum (also called a “squirrel cage”).

The stator of the motor unit contains a pair of working windings, one of which is the main winding, and the second serves as a starting winding. They are located in relation to one another at right angles, or are wound in opposite directions, forming a kind of “bifilar”. The current flowing through the main winding creates an electromagnetic field with a changing vector direction. When the rotor rotates, according to the law of electromagnetic induction, a resultant magnetic flux (EMF) is created in the motor. As a rule, it is enough to support its rotation due to the current flowing through the main coil.

If the rotor is stationary in the initial position (which is considered normal), then the resulting EMF approaches zero. In this case, to start the engine, additional force will be required to provide the required starting torque. For these purposes, a starting coil is needed.

For the motor to start and operate normally, the currents in the coils must be out of phase with one another. For this reason, its design includes an additional phase-shifting element (choke or capacitor). As soon as the engine develops the required speed, the need for a starting coil disappears.

Conclusion: To start the blood pressure normally, you need to use both coils at once (main and starting). On the other hand, for regular rotation of the rotor, only one is enough - the main one. For timely switching of these circuits, a starting relay is used, which is switched on directly in front of the compressor.

Connecting a compressor without a switch

Connecting a compressor to a system without a relay is carried out according to the diagram that we have given below.

Motor connection diagram without relay

You need to take a conductor with two wires on one side and a plug on the other side. One contact should be connected to the main point, and the other to the working winding. Now these contacts should be connected and the plug plugged into the socket. In this case, a working refrigerator will function.

Video - Connecting a compressor without a switch

Description of the main elements of the refrigerator

Each piece of equipment participates in the overall heat exchange. It is thanks to the correct functioning of the devices that a constant and sub-zero temperature is maintained in the chambers of the unit. In order to understand how this happens, it is necessary to take a closer look at the operation of each element.

Motor-compressor: functional purpose

This is the main unit of the device, which ensures smooth circulation of the refrigerant in the heat exchange system. Up to two compressors are installed in the unit, depending on the purpose.

The main function of the motor is to move the compressor. This means that it is responsible for the process of converting electrical energy into movement of the compressor. Improved models of devices are equipped with piston compressors, inside of which there is an engine. Thus, the possibility of loss of freon is eliminated, so the units are less susceptible to breakdowns.

Let's sum it up

Even if connecting a compressor seems like a difficult task, after studying the diagram you will be able to cope with the process. Here it is necessary to follow a sequence of actions, work slowly and thoughtfully. Good luck!

How to get rid of an unpleasant smell in the refrigerator? A special publication will examine various ways to combat this unpleasant phenomenon, using ready-made formulations designed specifically for such purposes, and improvised means, some of which can be found in every kitchen.

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Checking the starting and running capacitors

You can check the capacitor using a capacitor capacitance meter; such devices are produced both separately and as part of a multimeter, a universal device that can measure many parameters. Let's consider checking with a multimeter.

de-energize the air conditioner
discharge the capacitor by short-circuiting its terminals
remove one of the terminals (any)
We set the device to measure the capacitance of capacitors
We lean the probes against the terminals of the capacitor
read the capacity value from the screen