High voltage testing of cable is an important process in the research, development, and production in the cable business. It is an important step of the manufacturing process to validate the integrity of cable insulation prior to its installation in a certain application. A high voltage cable test may include alternating current withstand, partial discharge, and direct current withstand to name a few. The cables have to be carefully designed in order to sustain higher voltage levels, thermal effects and to be more reliable, making this High Voltage Cable Testing Equipment very important in the wire and cable industry.
The quality of a cable testing equipment must be essential for the proper use and the results of the testing itself due to the necessary precision. Without this, any test made to the cables may be inaccurate and even dangerous to the equipment, damaging heavily its components and also the equipment to the test.
All electrical High Voltage Cable Testing Equipment by Udeyraj is able to tolerate overvoltage during normal conditions which is a very common situation during electrical storms or electrical system failure inside the house, company or industry. That’s why an excellent quality high voltage cable testing can be broadly classified into the following tests:
Testing of insulating materials (dielectrics)
This test is carried out on dielectric samples; the test is aimed in permittivity measurement, per unit volume dielectric loss, and the measurement of dielectric strength for each insulating material. The permittivity measurement and the per unit volume dielectric loss can be measured by using a Schering Bridge of High Voltage. This Bridge is used to measure: the capacitance of the capacitor and the dissipation factor.
Sustained low frequency tests
This test is made upon specimens of insulation materials for the determination of dielectric strength and the dielectric loss, for routine testing, as well as for examinations on porcelain insulators and transformers. Since the electric stress has a significant effect on the dielectric loss, the examinations are done at very high stress values.
Tests on completed equipment
There are several tests taken on completed equipment, such as: measurement of capacitance, power factor (or total dielectric loss), breakdown voltage and flash-over voltage. The breakdown voltage test is only done on a limited number of samples since, the breakdown voltage test permanently damages and destroys the equipment forever.
Since all equipment needs to stand up to a fixed voltage without any damage under operation, all equipment are subject to withstand the test about twice the normal voltage, but a lot lesser than the breakdown test.
High Voltage direct current tests
This test is done on equipment expected to operate under direct voltage conditions, and also where, due to the inconvenience of the usage of high voltage transformers needed for extremely high tension voltage regarding to alternating tests and since there are usually transportation problems, these tests aren’t easy to be done after the installation of transformers.
High frequency test
High voltage tests are done during the manufacturing stages for the sake of obtaining a design of insulator that will withstand the whole conditions of service satisfactorily.