Three important indicators for quality inspection of wires and cables

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Three important indicators for quality inspection of wires and cables

Author：Henan Shenghua Cable Click： Time：2019-10-09 00:00:00

Choosing qualified wires and cables is crucial for production and daily safety. In addition to understanding common knowledge about wires and cables, it is also necessary to conduct routine inspections on wires and cables. Today, we will talk about the three important quality inspection indicators of wires and cables.

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Insulation resistance testing:

Insulation resistance test is an important indicator reflecting the insulation performance of cables. The strength and softness of insulation performance directly affect the electrical strength, dielectric loss, and service life of insulation materials of cables. Generally, insulation resistance test requires that the insulation resistance of cables should be higher than the required value, because low resistance can cause power supply leakage problems, endanger production safety and personnel life. Therefore, the purpose of the test is to require the test value of insulation resistance to be higher than the specified value.

At present, in addition to using an ohmmeter (megohmmeter), the commonly used methods for measuring the insulation resistance of wires and cables are the galvanometer comparison method and the high resistance meter method (voltage current method).

Measurement of capacitance and loss factor:

Capacitance and loss factor are important factors that directly limit cable capacitance and transmission distance, so cable capacitance is also a very important testing parameter.

By testing the capacitance and loss factor, it is possible to check whether the cable is damp, and whether the insulation and shielding layers are detached. Therefore, in practical life, testing is also very necessary.

Partial discharge measurement:

Oil paper cables generally do not require partial discharge testing, but it is very necessary for extruded cables because the possibility of partial discharge in extruded cables is very high, and partial discharge can also cause serious damage to plastics and rubber. When working in environments with high voltage levels and strong working fields, the problems caused by partial discharge will be more serious. Therefore, checking partial discharge testing when extruded cables leave the factory is also a safety consideration

There are many methods for measuring partial discharge nowadays, including charge exchange, measurement of discharge pulses, and measurement of voltage using ultrasound. However, the most commonly used method nowadays is still to measure discharge pulses, which we call electrical measurement.

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Three important indicators for quality inspection of wires and cables

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