Refrigerator Start-up Relay: Design and Work

Features the purpose of starting the protective relay of the refrigerator compressor motor. Options for a possible choice and the feasibility of self-replacement parts of the refrigerator. When using a three-phase motor of the refrigerator, setting the starting winding is not necessary. When connected to a 380 V network, the device operates in such a way that all stator coils are phased out independently. However, when using a 220 V network, it becomes necessary to use additional components( triangles and stars schemes with the presence of a compressor).

This feature allows you to check and provide the required voltage in one of the windings, with respect to the other at 90 degrees. Thus, the first winding is a starting winding, and the compressor motor will shut off at maximum speed. The system used when connecting the refrigerator to the 220V line actually makes a two-phase analogue of a three-phase motor.

Features of starting an asynchronous type motor when using a single-phase network. As you know, 380V is formed from three phases of 220V, but in this case we are talking about the real value, but not about the amplitude( the parameter causing thermal effect with passive resistance).Simply put, the values ​​of alternating voltage are constantly changing, therefore, for convenience, they are averaged. This is considered an effective value.

Features of the

refrigerator relay In order for the motor to function asynchronously, installed in the refrigerator, the field inside must necessarily rotate. However, it is possible to provide and verify the necessary factor by applying to the three windings the phases of the corresponding value. The result of the action is the vector addition of the fields, which ensures rotation, which also carries the rotor. Indicators that are available when connecting a three-phase motor to a 380 V line are the highest of all types of connections. This becomes the reason for the wide use of the process in industrial production, but it is not very suitable for domestic refrigerators.

In the presence of only one phase, the rotation of the field is basically impossible, since at least two vectors are required for movement. The installation of a compressor that provides a voltage shift of 90 degrees helps to obtain the required performance in the conditions of private apartments and houses. The alternating field received in the process of rotation activates the rotor in the desired direction. Of course, the process is not as smooth as in the presence of three vectors, but this is enough for the operation of household appliances.

The presence of three-phase voltage in private homes to connect the refrigerator is not provided. But why? The reason is the need for special skills and knowledge of the theory, which is quite difficult for the perception of the average man in the street. With the presence of one phase and one land, the use of household appliances becomes simple and convenient, which allows you to miss the performance for the sake of comfort.

So what does the starting winding do? At the beginning of the engine start, the relay provides the creation of the second vector, due to which the field formed in the process can be considered rotating. Not being an even circle, its performance is sufficient for the promotion of the rotor. At full speed, to save energy and increase efficiency, the starting coil of the refrigerator is turned off.

The principle of operation of the start-up relay of the refrigerator

How does the start-up coil go off when the speed is reached? At the beginning of the relay, the maximum energy consumption is observed, on which everything is based. In addition, often the starting relay is used for additional protection. Shutdown is carried out at a warming up of a special element. After reaching the maximum value, the chain loses its integrity, regardless of whether the set mode of the refrigerator has been reached. There are the following operation schemes for the starting relay:

“Tablets”.Made from a substance that can expand when heated. When you turn on the refrigerator, the part is cold. However, with a gradual increase in temperature, the contact opens, due to which only the coil remains functioning. Some experts believe that maintaining the desired mode can be achieved through the use of a choke working winding. You can verify this by experience.

Induction relays operate on the principle of the interaction of electromagnets. During the launch of the system, the refrigerator consumes the maximum amount of energy, which leads to the interaction of the core and the starting coil contacts. When the current drops further, the mechanism is weakened and the connections open.

It is important to note that, together with tablets, often the device case is also equipped with thermal relays installed on bimetallic plates. This allows you to open the contacts immediately after exceeding the threshold. The operation of this type of relay is carried out by heating the sensitive element. This scheme of protection of the compressor is considered one of the most common for household appliances.

The design of the start-up relay

The start-up, or starting relay, used in some models of refrigerators, is shaped like a tablet. This element is located at the casing of the compressor motor( black detail).Interesting, but for this part, manufacturers always choose black. But why?

Black color is able to absorb and emit heat. The movements of the process depend on the temperature difference of the external environment and the compressor. In situations where the motor heats up, heat is generated. To speed up the cooling process, a fan is sometimes used, due to which the heat quickly goes into the surrounding space.

Starting protection element, as a rule, has:

• phase at 220 V and grounding phase( with two inputs);
• starting and working winding of the induction motor, as well as the phase of the ground( with three inputs);

The colors in which the wires are painted help to facilitate the process of connecting the refrigerator for the consumer. However, even under obvious conditions, it is recommended to repair the refrigerator and its components carefully. To determine the ground of the compressor, you can remove a small layer of paint from the case, which will provide an opportunity to check all the contacts. Despite the simplicity of this method, it is better to leave it in case other options are excluded.

Location of the device

The relay of the compressor of the RTP-models has some differences, and can be located on the wire( without attachment to the frame).The working process, at the same time, is carried out with a DCM compressor, and differs from DHR by a smaller current performance when triggered. Such a device makes it possible to qualitatively protect the compressor in the presence of a similar lowering current.

Before purchasing a relay, it is important to check its compliance with the type of compressor. Quality installation also matters. The best option when choosing a device is to purchase a brand of product similar to that previously installed.