What are the technical knowledge of wire and cable inspection

It includes the following aspects:

1. Quality inspection of raw materials, auxiliary materials, purchased and product-related parts for the manufacture of wires and cables;

2. Inspection of machinery and equipment used in the manufacture of wires and cables;

3. Inspection of fixtures, molds and process equipment used in the manufacture of wires and cables;

4. Supervision and inspection of the structure card of each process of manufacturing wires and cables.

5. Inspection of various formulas used in the manufacture of wires and cables;

6. Factory inspection of wires and cables after completion;

7. Inspection of the production environment of manufacturing wires and cables;

8. Inspection of measuring tools, scales and instruments used in the manufacture of wires and cables.

There are many ways to inspect wire and cable products, which can be divided into the following according to the different inspection methods and functions

1. According to the process stage: pre-inspection and intermediate inspection;

2. According to the inspection location: fixed inspection, mobile inspection or patrol inspection;

3. According to the inspectors: self-inspection, self-inspection and full-time inspection;

4. According to the number of inspections: general inspection and sampling inspection;

5. There is also a preventive test, which usually refers to the first article inspection and statistical inspection. The first article inspection is the quality inspection of the first activity. The so-called statistical test is a test method that uses the principles of mathematical statistics and probability to determine the quality of products and their development trends through the inspection and analysis of a certain number of products.

6. Factory testing tests include routine tests, sampling tests and type tests.

Cable inspection typically requires checking the following items:

Visual inspection: check whether there are scratches, wear, deformation, cracks and other physical damage or chemical corrosion on the surface of the cable sheath, and check whether the identification, nameplate and length of the cable meet the requirements.

Insulation Resistance Test: Using a resistance tester or insulation tester, measure the resistance value of the cable insulation layer to evaluate the insulation state of the cable.

Wire-to-wire resistance test: Use a test instrument such as a multimeter to measure the resistance value between wire-to-wire in the cable to determine whether the conductor of the cable is damaged.

Dielectric damage detection: use AC withstand voltage tester to test the insulation damage of the cable under normal working voltage, such as flashover discharge.

Steel wire armor detection: check whether the cable steel wire armor is complete, whether there is broken wire, rust, loosening and other phenomena.

Cable gland and terminal detection: check whether the contact between the cable connector and the terminal is good and whether the fastening is firm, and check whether the waterproof and anti-corrosion measures at the cable gland and terminal are in place.

Reliability test: Evaluate the reliability and performance of the cable by conducting high-voltage tests, heat resistance tests, cold resistance tests and other tests.

These test items can effectively evaluate the safety and reliability of cables, prevent cable accidents, and ensure the stable operation of the project.

Cable testing items:

Conductor resistance, insulation thickness, insulation thinnest point thickness, sheath thickness, sheath thinnest point thickness, insulation resistance, insulation resistance at 70, immersion voltage, dimensions, cable stranding direction.

Main inspection contents:

Mainly check the quality of the cable, insulation and various tests on the cable line, because the power cable is used to transmit high-power electric energy, working under high voltage and high current conditions, so its electrical performance requirements are very high, in order to check the manufacturing and installation quality of the cable, reduce the operation accident, improve the reliability of power supply, must carry out the performance test.

1. The appearance is standard, there must be a certification mark, manufacturer, wire diameter, etc. on the wire, and the ground wire is insulated with a yellow-green layer.

2. Mechanical strength.

3. The insulation (generally greater than 100m) and voltage strength of the sheath (above 500V and below 1500V).

4. Line resistance (no greater than a certain resistance under a certain wire diameter, conductivity and length).

5. Under the high temperature impact of 140 degrees, the wire shall not crack at the low temperature of -30 degrees.

Cable test is to check the quality of the cable, insulation and various tests done on the cable line, because the power cable is used to transmit high-power electric energy, generally working under high voltage and high current conditions, so the requirements for its electrical performance are very high, in order to check the manufacturing and installation quality of the cable, reduce the operation accident, improve the reliability of power supply, must carry out the performance test.

1. Visual inspection

Check whether the insulation skin is smooth or damaged, the thickness is uniform, the core is not oxidized or corroded, and the number of strands meets the requirements; Check whether the printing on the surface of the insulating skin is clear and dirty, and the certification code must meet the requirements of UL and 3C to recognize the letter and cherry tree.

2. Packing inspection:

Check whether the cable packaging meets the storage and transportation requirements, the cable model should be the same as its specifications, and the identification needs to be clear and complete; Check that the outer packaging is not damaged or deformed; The product model and color are consistent with the outer packaging logo, and the packaging and bundling meet the requirements.

3. Structural size inspection:

According to the structural size requirements of the power cord and the actual use requirements, the key size of the power cord is measured with vernier calipers, and the allowable error is very small.

6. Temperature resistance test:

Set the oven temperature to 105 plus minus 2 degrees Celsius, and then put the wire to be tested for 24 hours, and the insulating skin cannot be shrunk and deformed.

7. Solderability test:

After removing the insulating skin of the power cord, solder it to the surface of the wire core with a soldering iron; The test requirements require the core to be shiny and well tinned.

8. RoHS inspection

**Manufacturer should provide proof of RoHS compliance.

Dear, hello, I have inquired for you, what are the types of supervision cable inspection methods; 1. Routine test method: Jane Laugh is an experiment conducted by the manufacturer on all finished cables. Its purpose is to check whether the quality of the product meets the requirements of the technical conditions, in order to detect accidental defects in the manufacturing process.

It is a non-destructive experiment like the DC resistance of the wire, the insulation resistance time. and withstand voltage test, partial discharge detection, etc. Second, the type test method:

It is a comprehensive performance inspection of the product by the manufacturer on a regular basis, especially for a new product before it is finalized and produced in batches, or when the structure, materials and main processes of a product have changed and may affect the performance of the cable. Through the type test, it can be verified whether the product can meet the requirements of operation and can be compared with the old product. Such as the thermal aging performance of insulation and sheath, long-term stability test of power cable, etc.

3. Acceptance test method: It is an acceptance test of the cable after the cable is installed and laid, so as to check the installation quality and find possible damage during construction. Such as the withstand voltage test after installation.

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Pro, the requirements for cable live detection are: the general requirements for instrumentation and equipment are as follows: 1

All instruments and equipment should be set up with a ledger, with an operation manual and a valid verification certificate. 2.The range and accuracy level of the instrument, the output voltage or current of the test equipment should meet the test requirements.

1.The whole process of operation (inspection, live detection and power failure test) should follow the relevant requirements of GB26859 and GB26860. 2.

Workers shall comply with paragraph 1. the requirements of Article 1; The instruments and equipment used should be respectful and meet the requirements of this article. 3.

The person in charge of the operation should have an understanding of the status of the equipment to be carried out in advance, including the conclusion of the previous operation report, whether there is any recent experience in bad working conditions, and family defect warnings. Special attention is paid to equipment that may be defective. For the leakage current test of power cables, it is required that the leakage current value of 5 minutes of pressurization should not be greater than the leakage current value of 1 minute of pressurization, and the leakage current unbalance coefficient between the three phases should not be greater than 2. For the DC leakage test of power equipment such as blind transformer, it is required that the leakage current value under the specified test voltage should not change significantly compared with the previous test results.

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Cable live detection is an important power safety inspection work, and its requirements mainly include the following aspects: 1Accuracy and reliability of testing instruments:

It is necessary to use cable live testing instruments with stable performance, high precision and good reliability to ensure the accuracy and reliability of the test results. 2.Safe Operation:

Before carrying out the cable live test, it is necessary to carry out safety standard operation and necessary safety measures, such as wearing protective equipment, avoiding contact with high-voltage lines, etc., to ensure the safety of personnel and equipment. 3.Condition of the detection environment:

The cable live detection must be carried out in a harsh weather environment without wind, rain, snow, frost and other weather to ensure the accuracy and reliability of the test results. 4.Use of detection parameters:

When carrying out cable live detection, the detection parameters must be set according to the requirements to ensure the accuracy and reliability of the test results. 5.Data Logging and Analysis:

The test results must be accurately recorded, and reasonable data analysis must be carried out in order to find and eliminate the hidden dangers of the cable in time. Extended Supplements:1

For the cable live detection of large-scale power equipment, it is also necessary to consider the details such as cable joints and cable terminals to ensure the safe and stable operation of the entire Hailner power system. 2.For different cable types and usage scenarios, different cable live detection technologies and methods are also required to improve the accuracy and efficiency of detection.

3.The service life and aging degree of the cable are also factors that need to be considered, and the state assessment and aging degree analysis of the source suspect cable need to be carried out when the cable is live tested, so as to take targeted maintenance and replacement measures. 4.

When carrying out cable live detection, it is also necessary to consider the influence of the cable laying environment, such as onshore, seabed, underground, etc., in order to choose the appropriate detection method and technology to ensure the effectiveness and reliability of the detection. <>