26
Nov
Why are cable conductors discolored?
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Wire and cable are an important part of the power system, and their performance is directly related to the safe operation of the whole system. When installing and using wire and cable, we often find that the cable conductor copper wire oxidation discoloration (blackening) problem. At this time, many people think that the blackened copper wire is of poor quality. no, no. Let me tell you the reason for the blackened copper wire, and how we should use the wire safely.
I. The main causes of conductor blackening
1. Oxidation reaction
Copper conductor in the air for a long time exposure will occur oxidation reaction, this process will form a layer of copper oxide protective film on the surface of the conductor. With the passage of time, this layer of oxide film will gradually thicken, the colour will change from light to dark, and ultimately show a black or dark brown. Temperature increases will significantly accelerate the oxidation process, especially in the conductor temperature exceeds 60 ℃, the oxidation rate will be greatly increased.
2. Overload heating
When a cable carries more current than its rated value, the conductor will generate excessive heat. Continuous overload operation will lead to a continuous rise in conductor temperature, accelerating the aging and deterioration of insulation materials. High temperatures will also promote the accelerated chemical reaction on the surface of the conductor, resulting in a darker surface colour, but also reduces the conductivity of the conductor.
3. Moisture corrosion
In a humid environment, moisture will be combined with pollutants in the air to form a corrosive solution. This solution will accelerate the chemical reaction on the surface of the conductor, especially in the environment containing sulfide or other corrosive gases, which will lead to a chemical reaction on the surface of the conductor and turn black. Long-term humid environment will also lead to a decline in the performance of the insulation layer.
4. Electrochemical corrosion
When different metals are in contact, a primary cell effect will be formed. For example, copper conductors and aluminium joints connected, in the presence of moisture, an electrochemical reaction will occur. This reaction accelerates the corrosion process of the metal, leading to blackening of the contact surfaces and possibly affecting the electrical conductivity.
II. Cable protection measures
1. Environmental protection
The installation site must be kept dry and ventilated, and direct exposure of cables to humid or corrosive environments should be avoided. When installed outdoors, waterproof and sun protection measures are required, and professional protective sleeves or protective grooves can be used. Regular inspection of the installation environment, timely removal of pollutants that may cause corrosion.
2. Temperature control
Need to strictly control the operating temperature of the cable, the installation of temperature monitoring devices for real-time monitoring. According to the load situation reasonable selection of cable specifications, reserve enough capacity margin. In the wiring, pay attention to avoid cable stacking each other, to ensure sufficient space for heat dissipation.
3.Professional installation
Installation must be carried out by qualified professionals to ensure that each joint is correctly processed. Installation should strictly comply with the bending radius requirements to avoid excessive bending caused by mechanical damage. All connectors must be connected with suitable terminals and ensure that the connections are tight and reliable.
III. The correct use of cable
1. Scientific selection
According to the actual use of the environment and load requirements to choose the right type of cable, the rated current should be considered more than 30% margin. Selection should take into account the cable temperature rating, insulation level and environmental adaptability. Must be purchased with formal qualifications of manufacturers of products, and product standards book, strict production.
2. Standardise operation
Establish a perfect operation management system, and record the cable operation parameters regularly. Install current monitoring devices to ensure that the operating current does not exceed the rated value. Regular infrared temperature measurement, abnormal temperature rise found in a timely manner.
3.Regular maintenance
Make a detailed maintenance plan, including regular inspection, testing and maintenance work. The inspection should include appearance check, insulation test and grounding test. Problems found should be dealt with in time and should not be operated with disease.
4. Joint protection
Professional terminals should be used at all joints to ensure that the contact surface is clean and free of oxidation. Regularly check the tightness of the joints to prevent heat generation due to loosening. Waterproof the joints in a humid environment.
IV. Recommendations for preventive measures
1. Design stage
In the system design should fully consider the cable protection requirements, reserve enough space for installation and maintenance. Design should consider the environmental factors, choose the appropriate wiring and protection level. Adequate maintenance channels must be reserved for future maintenance.
2. Installation stage
Installation should be carried out in strict accordance with the specifications, and protective measures should be taken at all crossing places. Installers must be professionally trained and use qualified tools and materials. Comprehensive inspection and testing should be carried out after the installation is completed.
3.Operation stage
Establish a sound operation and management system, and carry out regular inspections and maintenance. Formulate emergency plans and deal with problems in time. Keep complete running records to provide a basis for maintenance.
The blackening of cable conductors is a complex process involving the joint action of a variety of factors. Through scientific protective measures and standardised use of management, you can effectively extend the service life of the cable to ensure the safe and reliable operation of the system. It is recommended that enterprises strengthen the management of the whole process of cable use to prevent problems from the source.
Only by doing a good job of prevention and protection can we ensure that the cable always maintains a good working condition and provides users with safe and reliable power supply guarantee. At the same time, pay attention to advancing with the times, using new technologies, new materials to enhance the level of protection of the cable, to achieve better results.
I. The main causes of conductor blackening
1. Oxidation reaction
Copper conductor in the air for a long time exposure will occur oxidation reaction, this process will form a layer of copper oxide protective film on the surface of the conductor. With the passage of time, this layer of oxide film will gradually thicken, the colour will change from light to dark, and ultimately show a black or dark brown. Temperature increases will significantly accelerate the oxidation process, especially in the conductor temperature exceeds 60 ℃, the oxidation rate will be greatly increased.
2. Overload heating
When a cable carries more current than its rated value, the conductor will generate excessive heat. Continuous overload operation will lead to a continuous rise in conductor temperature, accelerating the aging and deterioration of insulation materials. High temperatures will also promote the accelerated chemical reaction on the surface of the conductor, resulting in a darker surface colour, but also reduces the conductivity of the conductor.
3. Moisture corrosion
In a humid environment, moisture will be combined with pollutants in the air to form a corrosive solution. This solution will accelerate the chemical reaction on the surface of the conductor, especially in the environment containing sulfide or other corrosive gases, which will lead to a chemical reaction on the surface of the conductor and turn black. Long-term humid environment will also lead to a decline in the performance of the insulation layer.
4. Electrochemical corrosion
When different metals are in contact, a primary cell effect will be formed. For example, copper conductors and aluminium joints connected, in the presence of moisture, an electrochemical reaction will occur. This reaction accelerates the corrosion process of the metal, leading to blackening of the contact surfaces and possibly affecting the electrical conductivity.
II. Cable protection measures
1. Environmental protection
The installation site must be kept dry and ventilated, and direct exposure of cables to humid or corrosive environments should be avoided. When installed outdoors, waterproof and sun protection measures are required, and professional protective sleeves or protective grooves can be used. Regular inspection of the installation environment, timely removal of pollutants that may cause corrosion.
2. Temperature control
Need to strictly control the operating temperature of the cable, the installation of temperature monitoring devices for real-time monitoring. According to the load situation reasonable selection of cable specifications, reserve enough capacity margin. In the wiring, pay attention to avoid cable stacking each other, to ensure sufficient space for heat dissipation.
3.Professional installation
Installation must be carried out by qualified professionals to ensure that each joint is correctly processed. Installation should strictly comply with the bending radius requirements to avoid excessive bending caused by mechanical damage. All connectors must be connected with suitable terminals and ensure that the connections are tight and reliable.
III. The correct use of cable
1. Scientific selection
According to the actual use of the environment and load requirements to choose the right type of cable, the rated current should be considered more than 30% margin. Selection should take into account the cable temperature rating, insulation level and environmental adaptability. Must be purchased with formal qualifications of manufacturers of products, and product standards book, strict production.
2. Standardise operation
Establish a perfect operation management system, and record the cable operation parameters regularly. Install current monitoring devices to ensure that the operating current does not exceed the rated value. Regular infrared temperature measurement, abnormal temperature rise found in a timely manner.
3.Regular maintenance
Make a detailed maintenance plan, including regular inspection, testing and maintenance work. The inspection should include appearance check, insulation test and grounding test. Problems found should be dealt with in time and should not be operated with disease.
4. Joint protection
Professional terminals should be used at all joints to ensure that the contact surface is clean and free of oxidation. Regularly check the tightness of the joints to prevent heat generation due to loosening. Waterproof the joints in a humid environment.
IV. Recommendations for preventive measures
1. Design stage
In the system design should fully consider the cable protection requirements, reserve enough space for installation and maintenance. Design should consider the environmental factors, choose the appropriate wiring and protection level. Adequate maintenance channels must be reserved for future maintenance.
2. Installation stage
Installation should be carried out in strict accordance with the specifications, and protective measures should be taken at all crossing places. Installers must be professionally trained and use qualified tools and materials. Comprehensive inspection and testing should be carried out after the installation is completed.
3.Operation stage
Establish a sound operation and management system, and carry out regular inspections and maintenance. Formulate emergency plans and deal with problems in time. Keep complete running records to provide a basis for maintenance.
The blackening of cable conductors is a complex process involving the joint action of a variety of factors. Through scientific protective measures and standardised use of management, you can effectively extend the service life of the cable to ensure the safe and reliable operation of the system. It is recommended that enterprises strengthen the management of the whole process of cable use to prevent problems from the source.
Only by doing a good job of prevention and protection can we ensure that the cable always maintains a good working condition and provides users with safe and reliable power supply guarantee. At the same time, pay attention to advancing with the times, using new technologies, new materials to enhance the level of protection of the cable, to achieve better results.
