الوصف

 
VLF cable testing is the cutting-edge technology for proof testing of fully operating medium voltage cables and the detection of faulty ones. 
 
The device under test must withstand a VLF (very low frequency) AC voltage for a preset testing time without flashover. 
 
The portable, high-performance and energy-efficient VLF test systems are used for testing cables with 0.1; 0.*5 and 0.*2  Hz . In accordance with guidelines, the dielectric strength of cables and joints must be checked after installation or repair. 

     The VLF test systems from Energoexport have high capacity and compact.  In total two portable systems are available, each with different voltage levels (*0 and *0 kVrms) of cosine rectangular squarewave.
 
Test system has several units that can be easily separated that facilitates easy transportation and use. For example, when tested substation insulators only one high-voltage unit can be used.
Internal timer with three fixed time interval (1, 5, *0 minutes) with a real time clock function. After timer tripping the test system automatically turns off testing mode.  VLF test systems has two ranges of measurements of output current—1 mA and *0 mA  with digital indication.