The hottest national standard of the people's Repu

2022-08-23
  • Detail

National standard of the people's Republic of China DC voltage test method for wire and cable

Chinese Jinan gold testing machine low price sales national standard of the people's Republic of China DC voltage test method for wire and cable

electric cables and wires

method for d.c. voltage testgb/t 3048.14-92 this standard refers to the relevant provisions of IEC ~ (1973) high voltage test technology. 1 subject content and scope of application this standard specifies the test equipment, sample preparation, test steps, test result evaluation and precautions for DC voltage test of wires and cables. This standard is mainly applicable to DC voltage withstand test of various types of power cables and their accessories, and communication cables can also be used by reference. 2 reference standards GB 311.2 ~ 311.6 high voltage test technology GB 2900.19 Electrotechnical terminology high voltage test technology and insulation coordination 3 test equipment test equipment shall meet the following requirements. 3.1 test voltage 3.1.1 unless otherwise specified in the product standard, the test voltage applied to the sample shall be a DC voltage with a pulsation factor greater than 5%, and the polarity of the test voltage shall be specified in the corresponding product standard. 3.1.2 the test voltage and withstand time applied to the sample shall be specified in the corresponding product standards. 3.2 the DC voltage generated by the test voltage is generally generated by the DC high voltage generator, which is mainly composed of voltage regulator, step-up transformer, rectifier element, filter capacitor, polarity conversion device and discharge resistance. The DC high voltage generator should be able to output the voltage and current required for the sample test. 3.3 measurement of test voltage the measurement error of the average value of test voltage shall not exceed ± 3%, and the average value of test voltage shall be measured by the DC high voltage measurement system in accordance with Article 2 of gb311.4. 4 sample preparation 4.1 for cable accessory products, unless otherwise specified in the corresponding product standards, the rigid PVC foamed plastic connected with it, as a "future material", is widely used in construction, decoration, furniture, advertising and other fields, and the cable length should generally not be less than 5m. 4.2 the sample shall be under the test pressure (oil pressure or air pressure) and test temperature conditions specified in the corresponding product standards. 4.3 before the test, the surface of the cable terminal head must be wiped clean to reduce the leakage current and prevent flashover and discharge along its surface. The DC high-voltage test shall be carried out under high temperature environmental conditions, and the influence of temperature on the terminal head should be paid more attention. 5 test step 5.1 wiring method: unless otherwise specified in the product standard, the wiring shall be in the following way. 5.1.1 the single core cable conductor is connected to the high-voltage end, and the metal sleeve or shield is grounded. 5.1.2 each conductor of multi-core cable shall be connected to the high-voltage end in turn, and other conductors shall be connected with each other and grounded together with the metal sleeve, shield or armor. 5.1.3 split phase lead clad (or aluminum clad) cables connect each conductor to the high-voltage end in turn, and other conductors are connected with each other and grounded together with the metal sleeve, shield or armor. 5.1.4 the communication cable shall refer to the provisions in Table 1. Wiring table 1. Schematic diagram of comprehensive element structure. Sample wiring mode (high voltage terminal → grounding terminal) no metal sleeve, metal shield, armor and no additional special electrode. There are metal sleeve, metal shield, armor or additional special electrode. Each conductor pair of single core wire, and all other conductors and metal sleeve, shield Armored connection grounding twisted pair all conductors a → all conductors Ba all conductors a → all conductors BB all conductors a+b → 0 three wire group A all conductors a → all conductors B + CB all conductors B → all conductors a + Ca all conductors a → all conductors B + CB all conductors B → all conductors a + CC all conductors a + B + C → 0 four wire group A all conductors a + B → all conductors C + DB all conductors a + C → all conductors B + Da all conductors a + B → all conductors C + DB all conductors Body a+c → all conductors b+dc all conductors a+b+c+d → 0 note: ① a, B, C in the table represent the conductor number of the core. ② In the table, O represents the utilization of metal sheath, metal shield, armor or additional special plastics in automobiles. 1. Temperature control range: + 30 ℃ ~ - 60 ℃ (room temperature ≤ 25 ℃) the prospect will be broader and wider. ③ "+" in the table represents mutual electrical connection. ④ Additional electrode refers to water tank, metal bead chain, graphite coating and wrapping

Copyright © 2011 JIN SHI