China's wire and cable manufacturing enterprises have reached 10,000, and the production technology and quality are also uneven. The industry's quality assurance system is still not perfect, and there is still a big gap between the quality of cables in western developed countries. In recent years, a large number of Black manufacturers produce inferior wires and cables and even fake well-known brands to defraud commercial interests. Fire and other safety accidents due to quality problems of electric wires and cables have occurred from time to time. Therefore, the inspection of wires and cables is extremely important. The country has gradually paid attention to the detection of electric wires and cables, and has also issued some strict production and quality regulations, which has, to a certain extent, promoted the improvement of the quality of wire and cable products in China.
1, first of all quality inspection, quality is the life of the enterprise, only by grasping good quality, in order to ensure that the quality of the products produced meet the requirements in order to prevent the occurrence of quality problems at the root. At this point, the production company may implement such methods as self-inspection, commissioned laboratory inspection, or verification report provided by the supplier by the factory.
2. Insulation resistance test, insulation resistance measurement of wire and cable must be converted into insulation resistance value per kilometer. Different from DC resistance, insulation resistance value is inversely proportional to the length of wire and cable; insulation resistance test of low voltage wire and cable The measured voltage is 100V, 250V, 500V and 1000V. Among them, the detection voltage of 100V and 500V is widely used in the quality inspection department; the length of the measured wire and cable is not clearly defined, but for the convenience of measurement and calculation, generally Take 10m for measurement.
3, mechanical performance testing, refers to the wire and cable aging before and after the tensile strength, the general direct use of electronic tension measuring instruments for measurement. The width and thickness of the middle part of the wire and cable to be measured are accurately measured by a thickness gage firstly, and then the sample is artificially aged in a blast oven, and then measured by an electronic tensile machine to record the elongation at break of the wire and cable. The distance and the maximum tensile stress can be used to calculate the tensile strength and elongation at break of the measured wire and cable before and after aging. The product can be judged by comparing with the product standard.
4, spark test, spark test must be removed before the wire and cable surface moisture, to avoid the flashover phenomenon caused by moisture, you can use the wind to remove moisture. Spark test is a key link in the production of wire and cable. Select the appropriate test voltage according to the insulation thickness of the wire. Because, too low voltage can not guarantee the quality of the wire meets the requirements, if it is too high, it will cause damage to the insulation performance of the wire. The spark test must ensure that the wire and cable stay in the high voltage test area for not less than 5 seconds, can be controlled by adjusting the take-up speed.
During the test, static electricity is usually generated on the surface of the wire and cable. Therefore, static electricity on the surface of the wire and cable should be removed immediately after the spark test to avoid damage to the production personnel. At the same time, in order to ensure that the test results are valid, the spark test must be periodically calibrated and checked for effective operation.
1, first of all quality inspection, quality is the life of the enterprise, only by grasping good quality, in order to ensure that the quality of the products produced meet the requirements in order to prevent the occurrence of quality problems at the root. At this point, the production company may implement such methods as self-inspection, commissioned laboratory inspection, or verification report provided by the supplier by the factory.
2. Insulation resistance test, insulation resistance measurement of wire and cable must be converted into insulation resistance value per kilometer. Different from DC resistance, insulation resistance value is inversely proportional to the length of wire and cable; insulation resistance test of low voltage wire and cable The measured voltage is 100V, 250V, 500V and 1000V. Among them, the detection voltage of 100V and 500V is widely used in the quality inspection department; the length of the measured wire and cable is not clearly defined, but for the convenience of measurement and calculation, generally Take 10m for measurement.
3, mechanical performance testing, refers to the wire and cable aging before and after the tensile strength, the general direct use of electronic tension measuring instruments for measurement. The width and thickness of the middle part of the wire and cable to be measured are accurately measured by a thickness gage firstly, and then the sample is artificially aged in a blast oven, and then measured by an electronic tensile machine to record the elongation at break of the wire and cable. The distance and the maximum tensile stress can be used to calculate the tensile strength and elongation at break of the measured wire and cable before and after aging. The product can be judged by comparing with the product standard.
4, spark test, spark test must be removed before the wire and cable surface moisture, to avoid the flashover phenomenon caused by moisture, you can use the wind to remove moisture. Spark test is a key link in the production of wire and cable. Select the appropriate test voltage according to the insulation thickness of the wire. Because, too low voltage can not guarantee the quality of the wire meets the requirements, if it is too high, it will cause damage to the insulation performance of the wire. The spark test must ensure that the wire and cable stay in the high voltage test area for not less than 5 seconds, can be controlled by adjusting the take-up speed.
During the test, static electricity is usually generated on the surface of the wire and cable. Therefore, static electricity on the surface of the wire and cable should be removed immediately after the spark test to avoid damage to the production personnel. At the same time, in order to ensure that the test results are valid, the spark test must be periodically calibrated and checked for effective operation.
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