THE Vero Low Frequency (VLF) cable testing is widely used for conducting diagnostics for the medium-voltage and high-voltage cables used in different types of machinery and equipment.
It is considered a huge advantage for an industry to conduct its own diagnostics by using Very Low-Frequency cable testing system which can be used for both field testing and it is also portable for space and transportation.
Conventionally, Direct Current (DC) voltage sources are widely used for field testing of cables but over the course of years and a series of testings, it was proven to be inefficient and ineffective to withstand the damages that may occur during the long run of being used.
Direct Current (DC) diagnostics compared to Very Low-Frequency cable testing have also shown some results conducted by some experts that it yields ambiguous results which are proven to be ineffective for both medium-voltage and high-voltage power cables because it needs an inherent capacity to be charged when energised and most equipment in different industries use a larger and heavier and even more expensive types of sources or power cables compared to its lower-frequency alternative equipment.
VLF cable testing is very important because it is considered a part of diagnostics and testings for quality standard purposes. The other usage of VLF cable testing can also be used in numerous purposes.
The VLF cable testing is used in applying power cables to simply withstand the approach for the detection of potential failures or faults in a cable insulation when there is a planned outage for a specific system or equipment. The cable that underwent testing must withstand an alternating current (AC) voltage in a specific testing time with the absence of a flashover.
Another important use for Very Low Frequency (VLF) cable testing is to determine different wave shapes which are typically sine and square to describe the voltage used during the testing by using the Root Mean Square (RMS) and peak voltage and determine its differences to each other depending on the electrical wave shape.
RMS is a commonly used mathematical method for the definition on how effective voltage or current of an alternating current (AC) wave has during a WWF cable testing or diagnostics. To calculate the test voltage levels, it uses a multiple of the cable’s phase-voltage and nominal phase or it is based on tables and the Very Low Frequency (VLF) cable testing time usually runs from 15 minutes up to an hour using a vlf testing equipment.
Before the final test voltage is reached, there should be a monitoring of the VLF cable testing or diagnostic to come up with some additional decision because there are specific types of cables that are ineffective or not good enough to become toa candidate in withstanding the testing and diagnostic and this can be determined when there is an indication at a lower voltage which is used to negate the necessity to perform a withstanding diagnostic or testing. The diagnostic parameter uses ma easurement that optimises test times.
These test times can be changed depending on the cable’s deteriorating diagnostic measurement while being tested.