What is the specific inspection method of wire and cable?

It can be used independently under the multi-pulse cable fault tester; In the pulse current mode, it needs to be used in conjunction with GD-2131 series integrated DC high-voltage generator; In the multi-pulse mode, it must also cooperate with the GD-4133S cable test multi-pulse coupler; After the ranging is completed, the GD-4132 power cable fault pointer must be used for accurate pointing. Together, they form a high-performance cable fault finding system that offers a wide range of innovative features.

Wires and cables are related to electricity safety, so they should be carefully selected. So do you know how to detect wires and cables? And what is the difference between wires and cables? Let's explain it to you.

1. How to detect wires and cables.

1. The thermal stability test is that the cable is heated by current while also bearing a certain voltage, and after a certain period of heating, some sensitive performance parameters are determined to evaluate the stability of the insulation. There are two types of insulation stability tests: long-term stability tests or short-term accelerated aging tests.

2. The insulation resistance type reflects the important indicators of the insulation characteristics of Luheng wire and cable products, and is closely related to the electrical strength, dielectric loss, and gradual deterioration of the insulating material in the working state.

3. The dielectric strength of wires and cables refers to the ability of insulating structures and insulating materials to withstand electric field action without breakdown damage.

4. The resistance of the wire is the main indicator of its electrical bucket leakage performance, and the core resistance is larger than the DC voltage due to the skin effect and the proximity effect surface when the AC voltage acts, but the difference between the two is very small when the electrical frequency is 50Hz, and now the standard can only require the detection of the DC resistance or resistivity of the wire core whether it exceeds the specified value in the standard.

2. What is the difference between wires and cables?

1. The wire is composed of one or several soft wires, covered with a light and soft sheath, and used to carry the conductive metal wire of the current.

2. The cable is composed of one or more conductive cores that are insulated from each other and placed in a sealed sheath. It can be covered with a protective cover for the transmission, distribution of electrical energy or transmission of electrical signals. The size is larger and the structure is more complex.

3. It is customary to call household cloth wires wires, and power cables are referred to as cables. Wires and cables mainly include bare wires, winding wires, power cables, communication cables and optical cables, and electrical equipment.

The above is an explanation of how to detect wires and cables and the difference between wires and cables.

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.

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.

The wire will generally be sent first to the sample and specification drawings for confirmation.

The color is compared with the color of the sample, and the number of conductors, diameter and outer diameter specifications of the conductor have auspicious parameters. It's a simple test.

Behind is the aging of wires, flame retardant, and environmental protection to be tested with professional equipment.

The project mainly does these two items: cross-sectional area resistance value.

The main production equipment of wire and cable includes extrusion machine, wire drawing machine, printing wheel, spark testing machine, etc., the production process is relatively simple, so the selection of raw materials is the key to determine the quality of wire and cable.

The relevant provisions of the state clearly point out that the copper wire of wires and cables should use electrolytic copper, and the purity should be, so that the raw materials are evenly drawn out of the silk, and have a luster, and the materials used in the production of wire and cable insulation must also meet the national standard of APS plastic, good formal production enterprises in the selection of raw materials, can purchase raw materials in strict accordance with the relevant provisions of the state, and its production equipment is more advanced, testing equipment such as voltage tester, conductor resistance meter, aging box, tensile meter, etc., production management is more reasonable, Therefore, the quality of the wire and cable products produced can meet the requirements stipulated by the state.

Take a look at the labels. Wire products are national compulsory certification products, and the 3C mark on the product is indispensable.

Second, look at the quality of copper wire.

When purchasing, you can cut off a small piece of plastic skin, carefully check the copper wire inside, and touch the top of the copper wire with the palm of your hand, which should feel flat and no stinging, and feel soft. The color of the copper wire of the regular wire should be bright and red, while the color of the inferior copper wire should be black and hard.

Third, look at the length. When buying, count the number of laps, and then measure the length of each lap, multiply the two numbers, and the number obtained is the actual length of the bundle of wires, pay attention to see if the length of each bundle of wires is enough for 100 meters.

1. Look at the wire surface mark - according to the national standard, the wire surface should have the continuous mark of the manufacturer's name, product model and rated voltage. This is conducive to finding the manufacturer in time when problems occur during the use of wires, and consumers must pay attention to this when purchasing wires.

2. Look at the appearance of the wire - pay attention to the appearance of the wire should be smooth and flat, the insulation and sheath layer should not be damaged, the logo printing should be clear, and there should be no greasy feeling when the wire is hand-molded. From the cross-section of the wire, the thickness of the insulation or sheath should be uniform on the entire circumference of the wire, and the insulation or sheath should not be off-core, and the insulation or sheath should have a certain thickness.

3. Look at the conductor wire diameter - pay attention to whether the conductor wire diameter is consistent with the cross-section indicated on the certificate, if the conductor cross-section is small, it is easy to make the wire heat and cause a short circuit. It is recommended that the wires used in household lighting lines should be square millimeters and above; Household appliances with large power such as air conditioners and microwave ovens should use wires with square millimeters or more.

7. The range of the megohmmeter is often up to several gigaohms, and the minimum scale is about 1 megaohm, so it is not suitable for measuring the resistance below 100 kiloohms.

Testing criteria.

1.Logo: "Rubber Insulated Cables with Rated Voltage 450 750V and Below Part 1: General Requirements" GB

2.Structure size: rubber insulated cable with rated voltage of 450 750V and below Part 2: Test method

3.Conductor resistance: rubber insulated cables with rated voltage of 450 750V and below Part 2: Test methods GB

4.Voltage test: "Rubber insulated cable with rated voltage of 450 750V and below Part 2: Test method" GB

5.Insulation resistance: rubber insulated cables with rated voltage of 450 750V and below Part 2: Test methods GB

6.Tensile test before and after aging: "General Test Methods for Insulation and Sheathing Materials of Cables and Fiber Optic Cables Part 11: General Test Methods - Thickness and Dimension Measurement - Mechanical Property Tests" GB

7.Non-flame retardation test: "Flame test of cables and fiber optic cables under flame conditions Part 11: Flame vertical spread test of a single insulated wire and cable Test device" GB T

Test items. Appearance: appearance, size, printed logo, insulation thickness, insulation thinnest point, thickness.

Physical properties: withstand pressure test, elongation change, tensile strength change rate, elongation at break.

Electrical performance: resistance test, insulation resistance test, power frequency withstand voltage test, impact electrical test, conductor resistance, insulation resistance.

Aging performance: elongation at break after aging, compressive strength after aging, elongation at break before aging, compressive strength before aging.

Metro cable: structure and size inspection, conductor structure, insulation thickness, shielding structure, sheath thickness, outer diameter, outer sheath, conductor DC resistance test, partial discharge test, 4h AC voltage test, thermal extension test, cable waterproof test and single bundle cable burning test.

Qingdao Boende Testing is a professional third-party wire and cable testing organization, which can issue various reports, national qualification reports, 053267731855

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.

The items of wire and cable testing are:

Conductor resistance, insulation resistance, thickness of the thinnest point of insulation, tensile strength change rate, elongation at break after aging, tensile strength after aging, elongation at break before aging, tensile strength before aging, withstand voltage test, insulation thickness, elongation change rate, external dimensions, printed signs.

Generally speaking, the most commonly tested are conductor resistance, insulation resistance and withstand voltage test.

Voltage, resistance, withstand voltage, current carrying capacity, insulation.

Basically, it will inspect the appearance, physical properties, aging properties, electrical properties, subway cables.