Vlf Cable Testing Voltage

This article reviews the application of very low frequency vlf ac high voltage test sets for commissioning and maintenance of shielded medium voltage cables.

Vlf cable testing voltage.

However there is a risk that the cable may be understated due to a combination of lower test voltage and allowed uncertainty of the measuring circuit. The most commonly used commercially available vlf ac voltage test frequency is 0 1 hz. Designs and manufactures industry leading high voltage test equipment for proof testing diagnostic testing high voltage breakdown testing and preventative maintenance testing. A very low frequency vlf withstand test is an ac withstand test usually carried out at a frequency between 0 1 hz and 0 01 hz.

In the first step a go no go statement is sufficient. Vlf cable testing makes use of ac voltages in a frequency range of 0 01. Very low frequency vlf withstand testing is the application of an ac sinusoidal waveform generally at 0 01 0 1 hz to assess the quality of electrical insulation in high capacitive loads such as cables. Vlf systems are advantageous in that they can be manufactured to be small and lightweight.

A vlf test. The implication of dc hipot testing. This combination of size and power makes very low frequency cable testing perfect for testing longer sections of cable and apparatus. Vlf testing can be classified as a withstand or diagnostic test meaning it may be performed as a proof test for acceptance or as a maintenance test for assessing the condition of cable.

Vlf cable testing is the cutting edge technology for proof testing of fully operating medium voltage cables and the detection of faulty ones. Vlf testing of shielded power cables by paul brooker consultant to techrentals division of tr corporation. The test is conducted on entire drum of cable rather than a test sample length. Vlf ac voltage testing methods utilize ac signals at frequencies in the range of 0 01 hz to 1 hz.

Vlf testing is performed with. Unlike with dc voltage testing very low frequency is not destructive to good insulation and does not lead to premature failures. During the test cables are subjected to a test voltage significantly higher than what they experience during normal operating conditions. Vlf cable testing very low frequency is a technique for testing of medium and high voltage mv and hv cables.

While supplies to railways and aircraft may use 162 3 of 400hz it is still a sinusoidal voltage waveform. Very low frequency testing for medium voltage and high voltage cables is a method for verifying the integrity of the cable insulation. The device under test must withstand a vlf very low frequency ac voltage for a preset testing time without flashover. Trusted for the most technically advanced portable and user friendly high voltage equipment on the market.

Making them useful especially for field testing where transport and space can be issues.