There are main conductor DC resistance, insulation resi […]
There are main conductor DC resistance, insulation resistance, finished voltage test and insulated core voltage test. Each item is very important. The conductor resistance directly reflects the electrical transmission performance of the wire and cable, which directly affects the temperature and life of the wire and cable during power-on operation.voltage drop, and operational safety, it mainly examines the material and cross-sectional area of the conductor. If the material of the conductor is not good or the cross-sectional area is seriously insufficient, the DC resistance of the conductor will be seriously exceeded.
This cable will increase the current when it is laid in the line. The loss when passing through the line causes the cable conductor itself to heat up, causing the insulation of the covered conductor to rupture, causing leakage, short circuit, and even fire in the power supply line, endangering the safety of people and property. The standard has strict regulations on the DC resistance value of the conductors of different specifications of wire and cable, and shall not exceed the value specified in the standard.
The insulation resistance, the finished voltage test and the voltage test between the insulated cores are all examined for the electrical insulation properties of the insulation of the wire and cable and the sheath. The insulation resistance is the resistance of the insulation between the two conductors. It should be large enough. Provide insulation protection.
The finished voltage test and the insulated core-to-core voltage test not only require the cable to have sufficient insulation capacity, but also require the insulation or sheath material to be uniform and free of impurities, the thickness is sufficiently uniform, and the surface must not have invisible trachoma, pinholes, etc., otherwise it will cause Partial breakdown during the withstand voltage test.