DTE-40 VLFvery low frequency testing device

DTE-40 very low frequency test set
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 very low frequency AC voltage for a preset testing time without flashover. 
The portable, high-performance and energy-efficient DTE test systems are used for testing cables with 0.1; 0.05 and 0.02 Hz . In accordance with guidelines, the dielectric strength of cables and joints must be checked after installation or repair. 
The very low frequency test systems from DTE have high capacity and compact with cosine-rectangular output 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, 30 minutes) with a real time clock function. After timer tripping the test system automatically turns off testing mode. DTE test systems has two ranges of measurements of output current—1 mA and 20 mA with digital indication.

Parameters
Output voltage, VLF mode (C-R squarewave), kV , max 40Fixed frequencies of VLF generator, Hz 0.1 0.05 0.02Capacitance in VLF mode, ОјF, max 0.3 0.6 1.5Max output voltage in AC continuous mode, kV 50Max output voltage in DC mode, kV +40/-40Output current in all modes, mA 14Current and voltage measurement error, % 3