Factors affecting the insulation resistance of USB panel mount

  • In the production of USB panel mount cable, the phenomenon of low insulation resistance is often encountered, and there are many factors that affect the insulation resistance value of USB panel mount cable. In fact, there are mainly four main factors that have a great influence on the insulation resistivity.

     

    1. The influence of temperature

    As the temperature increases, the insulation resistivity decreases. This is because of increased thermal motion, increased ion production and migration. Under the action of voltage, the conduction current formed by the movement of ions increases and the insulation resistance decreases. Theory and practice show that the insulation resistivity decreases exponentially with the increase of temperature, and the conductance increases exponentially with the increase of temperature.

     

     

    2. The effect of electric field strength

    When the electric field strength is in the relatively low range, the mobility of the ions increases in a proportional relationship with the electric field strength. The ionic current and electric field strength follow Ohm's law. When the electric field strength is relatively high, the mobility of the ions gradually changes from a linear relationship to an exponential relationship as the electric field strength increases. When the electric field strength is close to breakdown, then a large amount of electron migration occurs, and the insulation resistivity is greatly reduced.

     

    3. The influence of humidity

    Due to the high conductivity of water, the size of water molecules is much smaller than that of polymer molecules. Under the action of heat, the polymer macromolecules and the constituent chains move relatively, so that the water molecules can easily penetrate into the polymer and increase the polymerization. The conductive ions in the material reduce the insulation resistance.

    This standard specifies immersion tests for various wires and USB panel mount cables. For example, before measuring insulation resistance, a rubber test piece is soaked in water for 24 hours. The purpose is to meet the influence of moisture and water on electrical performance during use.

    Insulation resistance is one of the main electrical properties of insulating materials, and it is also an important indicator of USB panel mount cable products or materials. Usually, the insulation resistance is required to be no lower than a certain value. If the insulation resistance value is too low, the leakage current along the USB panel mount cable will inevitably increase, resulting in wasted power. At the same time, the electrical energy will be turned into thermal energy, preparing for thermal breakdown and increasing the possibility of thermal breakdown.

     

    The effect of material purity

    Impurities are mixed into the material, increasing the conductive particles in the material and reducing the insulation resistance. Therefore, the insulation resistance of a certain rubber and plastic material will reflect the purity of the material and verify whether it meets the standard.

    During the production process of the USB panel mount cable, the process does not strictly follow the operating procedures, the mixed impurities and materials are foamed due to moisture, the deviation of the insulating core or the size of the outer diameter is smaller than the standard, the insulation delamination or cracks, the insulation scratches, etc., will reduce the insulation of the product. resistance.

    Therefore, in order to check the insulation resistance, it is necessary to check whether there is a problem in the process work. During the use of the USB panel mount cable, measuring the change of insulation resistance can also check the insulation damage to prevent accidents.