About refrigeration compressor overload protector, we must understand these things

1. Why does the compressor produce overheat protection?

The working principle and classification of the overload protector. The overload protector of the compressor for air-conditioning is generally a jump-type bimetal protector, which is composed of a heating wire, a bimetal and two static contacts, which are connected in series in the compressor circuit. .

When the current in the circuit is too large, the heating wire is hot and the dish-shaped bimetallic sheet is baked. When the bimetallic sheet heats up, it will arch in the opposite direction, thereby disconnecting the contacts; when the temperature of the compressor casing or motor is too high Even when the working current is normal, the heating wire generates little heat.

The bimetallic sheet also deforms and bends upwards, detaching from the two static contacts and cutting off the circuit. This protector can automatically reset and has the dual protection function of over current and over temperature rise.

Second, the working principle and classification of overload protector

1. Working principle of overload protector

A. The overload protectors of refrigeration compressors used in general refrigeration systems are sudden bimetal protectors.

B. This protector is mainly a complete circuit composed of heating wire, bimetallic sheet and two static contacts, and then connected in series to the circuit where the refrigeration compressor is located.

C. Its working principle is that when the current in the system circuit increases for no reason, the heating wire will generate a lot of heat. When the bimetallic piece is baked under the heat of the heating wire, it will become reversely arched, so as to achieve the purpose of disconnecting from the electric shock, cutting off the entire circuit.

D. Even if the current in the circuit is very small, but the temperature of the casing or motor of the refrigeration compressor is too high, the same phenomenon will occur. Therefore, the safe operation of the refrigeration compressor is effectively protected. More convenient is that this protection can be automatically reset, so it is very convenient during use.

2. Classification of overload protectors

Under normal circumstances, overload protectors are classified according to different installation methods, mainly divided into external and built-in overload protectors:

A 、 Related introduction of external overload protector

External overload protectors are generally installed on the sealed terminals of the refrigeration compressor shell, to keep close to the cover, so as to ensure sensitive sensing of abnormal temperature on the refrigeration compressor shell;

Because there is a process of conduction and convection from the heat transmission of the motor to the casing of the refrigeration compressor, there is a process from the heat of the casing to the perception of the overload protector, so the accuracy and reliability of this method are not particularly good. Therefore, the reason why external overload protectors are widely used is more because their manufacture is relatively simple and the cost is relatively low.

At the same time, the external overload protector also has obvious advantages such as easy installation and maintenance, so in some small power electrical aspects, it is used more;

B 、 Related introduction of built-in overload protector

The built-in overload protector is subdivided into two types: binding type and plug-in type: the binding type overload protector, as the name implies, is tied to the motor coil, so as to directly sense the temperature change of the coil. The advantage is that the response is very sensitive and accurate;

Plug-in overload protector is the installation method of the protector is directly plugged into the sealed terminal, the main principle is to sense whether the temperature of the motor is normal through the heat conduction of the refrigerant. This kind of protector has certain limitations, that is, it is very sensitive when there is no refrigerant leakage, but if there is a refrigerant leakage, this protector will be useless.

Therefore, overall: the external overload protector is relatively inferior to the built-in type in sensitivity, accuracy and reliability, but its cost is much lower, but its cost is relatively much lower, so there is also a certain market space. But compared to the built-in type, the scope of adaptation is still much smaller. But the cost of the built-in overload protector is several times higher than the external one. Therefore, friends can make corresponding choices according to their own use conditions and requirements.

3. Precautions during use of overload protector

1. The overload protection of the refrigeration compressor is completely different according to the configuration of the refrigeration compressor. On the whole, the sensitivity and accuracy of the built-in overload protector are much higher than that of the external overload protection. Compressor, so its protection for refrigeration compressors is also much greater;

2. In the case of insufficient refrigerant or leakage, the protection effect of the two overload protectors is very limited, so in order to prevent weak protection, a complete refrigeration system generally needs to add special protection against refrigerant shortage;

3. In the case of too much refrigerant, the protection of the two overload protectors is also limited, so there must be corresponding supplementary measures to ensure that the refrigeration compressor is not damaged;

4. In the case of high compression ratio, the protection effect of the overload protector is also very weak, so it is also necessary to set a low-pressure protection measure to protect the refrigeration compressor.

All Categories

About refrigeration compressor overload protector, we must understand these things

Recent related posts

About refrigeration compressor overload protector, we must understand these things

GLOBAL REFRIGERATION COMPRESSOR MARKET ON TOP TRENDING KEY PLAYERS Mitsubishi Compressor Bristol Compressor

Liquid Refrigerant, Dense Vapors Can Damage Compressors

Top 3 Applications for a Servo Motor

Danfoss cocuses on providing energy efficient, sustainable and smart refrigeration compressors for a varied range of commercial applications such as cold rooms

Customers frequently viewed

Welcome to O&Kmarts