Vlf Cable Testing Voltage

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 voltage.

Vlf testing is a withstand test usually carried out at a frequency of between 0 1 hz and 0 01 hz rather than 50 60 hz. The device under test must withstand a vlf very low frequency ac voltage for a preset testing time without flashover. This combination of size and power makes very low frequency cable testing perfect for testing longer sections of cable and apparatus. Vlf systems are advantageous in that they can be manufactured to be small and lightweight.

The test is conducted on entire drum of cable rather than a test sample length. While supplies to railways and aircraft may use 162 3 of 400hz it is still a sinusoidal voltage waveform. A vlf test. 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.

Vlf testing is performed with. Very low frequency testing for medium voltage and high voltage cables is a method for verifying the integrity of the cable insulation. Vlf cable testing very low frequency is a technique for testing of medium and high voltage mv and hv cables. Vlf testing of shielded power cables by paul brooker consultant to techrentals division of tr corporation.

This kind of test is suited for testing high capacitance loads such. The most commonly used commercially available vlf ac voltage test frequency is 0 1 hz. Making them useful especially for field testing where transport and space can be issues. Trusted for the most technically advanced portable and user friendly high voltage equipment on the market.

In the first step a go no go statement is sufficient. The implication of dc hipot testing. 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 is the cutting edge technology for proof testing of fully operating medium voltage cables and the detection of faulty ones.

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 cable testing makes use of ac voltages in a frequency range of 0 01. 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. During the test cables are subjected to a test voltage significantly higher than what they experience during normal operating conditions.

Unlike with dc voltage testing very low frequency is not destructive to good insulation and does not lead to premature failures.