PORTABLE HIGH-VOLTAGE VLF TEST SYSTEM
The system is designed for VLF (0.1 Hz) withstand testing of cross-linked polyethylene (XLPE) insulated cables.
Apart from very low frequency (VLF) and DC withstand testing, VLF-60 system also performs cable fault conditioning by initial burning faulty insulation, tests cable sheath and pinpoints its faults.
The system allows to carry out tests in both automatic and manual control modes.
In the manual mode the operator enters all test parameters, which makes VLF‑60 suitable for testing a wide range of electrical equipment according to various standards and regulations.
In the automatic mode minimal test settings entries are required: the operator only selects a test object type and voltage rating and the system automatically sets all the necessary test parameters according to IEEE 400.2-2013.
At the start of every test, VLF-60 measures the resistance and capacitance of an object under test. Based on the obtained results, the system evaluates its power output capability. If the system is not able to output the voltage of a required magnitude and frequency for a given load, it will automatically reduce the output frequency. Thanks to such output frequency optimisations, the VLF-60 can be used effectively for testing objects with capacitance up to 10 µF.
Non-volatile memory of the system capable of storing up to 10,000 test reports.
It is possible to search and view test reports right from the display of the system.
Test reports may be exported from the system to a USB memory stick in CSV or PDF format without using a PC.
The main user interface component is a touch-sensitive colour TFT display, which is used for navigating menus and entering data. During a test, an output voltage wave is visualised on the display in real time.
VLF-60 system is fitted with carrying handles and weighs only 64 kg, which enables operational comfort both in the lab and in the field conditions.
✓ Dual discharge device (internal automatic protection).
✓ Visual indication of high voltage presence on an object under active test.
✓ Visual indication of residual or stray voltage presence on an object after conclusion of a test.
✓ Sound alarm when high voltage is switched on.
✓ Emergency stop button.
✓ Operator keylock switch.
✓ Protective earthing.
|Output voltage||Setting and measurement range:|
|• Sinewave||0.1 … 62 kVpeak (44 kVRMS)|
|• Bi-polar pulse||0.1 … 62 kVpeak.|
|• DC+||+ 0.1 … 60 kV|
|• DC-||- 0.1 … 60 kV|
|• Vacuum bottle test||- 0.1 … 60 kV|
|• Sheath test||- 0.1 … 10 kV|
|• Sheath fault location||+ 0.1 … 10 kV|
|Measurement resolution||0,1 kV|
|Relative accuracy||± [2 % + 2 dgt1]|
|Indication||Real time wave visualization|
|Output current||Setting and measurement range:|
|• Sinewave||0.1 … 40 mApeak. (26 mARMS)|
|• Bi-polar pulse||0.1 … 40 mApeak.|
|• DC+||0.1 … 40 mA|
|• DC-||0.1 … 40 mA|
|• Vacuum bottle test||1 … 1000 µA|
|• Sheath test||0.1 … 40 mA|
|• Sheath fault location||0.1 … 40 mA|
|Measurement resolution||1 µA; 0.1 mA|
|Relative accuracy||± [2 % + 2 dgt]|
(sinewave, bi-polar pulse)
|Output frequency||0.01 …0.1 Hz with 0.01 Hz step|
|Frequency selection||• Automatic
|Output power||up to 1200 W|
|Breakdown management||Burn on Arc (keep arc burning)||Conditioning (burning) duration is set in the range of 1-5 minutes|
|Trip out on Arc (current limit trip)||If a flashover is detected, a test is stopped|
|Object under test||Capacitance measuring range2||0,1 nF … 12 µF|
|Resistance range||10 kOhm … 20 kOhm|
|Maximum load||• 1.0 µF at 0.1 Hz, 44 kVRMS (3 km for a typical cable with capacitance 330 pF/m)
• 5.0 µF at 0.02 Hz, 44 kVRMS (15 km for a typical cable with capacitance 330 pF/m)
• 10.0 µF at 0.01 Hz, 44 kVRMS (30 km for a typical cable with capacitance 330 pF/m)
|Duty cycle||Continuous, unlimited|
|Metering||• Voltage and сurrent (RMS and/or peak)
• OuT capacitance
• OuT resistance
• Test time
• Breakdown (flashover) voltage and current
|Controls and interfaces||Connection interfaces||• USB-A (user memory stick, formatted under FAT32)
• USB-B (service only)
• RS-485 (service only)
|Display||5,7" colour TFTT 640×480 px, capacitive multi-touch|
|Secondary control interface||Rotary encoder|
|Internal memory||10,000 test reports|
|Safety||Protective devices||• Automatic internal dual discharge
• Indication of high voltage presence on the load
• Emergency stop button
• Power keylock switch
• Thermal circuit breaker
|IP 21 (with lid closed)|
|Power supply and consumption||Supply voltage||110 …230 V ±10 %, AC|
|Supply frequency||50 / 60 Hz|
|Power consumption||1,5 kV·А|
|Physical||Dimensions, H×W×D||528×577×408 mm|
1 dgt – an error in least significant digits, that is constant regardless of the input.
2 Values measured on the high AC voltage may significantly differ from the values measured by a standard low-voltage multimeter.