Vlf Cable Test

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 test.

Vlf ac test voltages with cosinerectangular and the sinusoidal wave shapes are most commonly used. The most commonly used commercially available vlf ac voltage test frequency is 0 1 hz. During the test cables are subjected to a test voltage significantly higher than what they experience during normal operating conditions. Vlf systems are advantageous in that they can be manufactured to be small and lightweight.

This combination of size and power makes very low frequency cable testing perfect for testing longer sections of cable and apparatus. Vlf testers are smaller and more practical than ac testers but output the same amount of power as a 50 hz mains device. This kind of test is suited for testing high capacitance loads such. 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.

Vlf ac voltage testing methods utilize ac signals at frequencies in the range of 0 01 hz to 1 hz. The main conductor of the hv test lead is then connected to the conductor of the cable under test. Vlf cable testing is the cutting edge technology for proof testing of fully operating medium voltage cables and the detection of faulty ones. Vlf cable testing very low frequency is a technique for testing of medium and high voltage mv and hv cables.

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. In the first step a go no go statement is sufficient. The hva28td vlf high voltage test set is an ultra compact lightweight 0 1 hz vlf cable tester with integrated tan delta diagnostics with monitored withstand test mwt testing and diagnostics in compliance with ieee400 smallest vlf td unit available. Vlf testing uses very low frequencies as part of an ac cable maintenance routine.

Unlike with dc voltage testing very low frequency is not destructive to good insulation and does not lead to premature failures. Making them useful especially for field testing where transport and space can be issues. Vlf testing uses very low frequencies as part of an ac cable maintenance routine. This combination of size and power makes very low frequency cable testing perfect for testing longer sections of cable and apparatus.

The device under test must withstand a vlf very low frequency ac voltage for a preset testing time without flashover. The hv test lead outside shield conductor is connected to the concentric neutral ground point of the cable under test.