VLF Hipot Test Standards You Need to Know
Very Low Frequency (VLF) Hipot testing standards, primarily governed by IEEE 400, IEEE 400.2, and IEC 60502-2, specify voltage, frequency, duration, and procedures for assessing cable insulation.
Key standards include:
IEEE 400.2-2024: 21IEEE 400.2-2024 focuses on field testing of shielded power cables up to 69 kV and includes guidance on diagnostic measurements.
IEC 60502-2:2014: 21IEC 60502-2:2014 addresses testing requirements for cables rated from 6 kV to 30 kV after installation.
IEEE 400.3 / IEC 60270: 22Apply VLF in order to detect and measure partial discharge. The IEEE 400.3 outlines a procedure for assessment and IEC 60270 provides the background for partial discharge testing of high voltage apparatus.
How to Choose the Right VLF Hipot Tester
H3: Key Selection Criteria:
Voltage Rating: Match the tester output to your cable system. 1Select VLF cable hipot testers by matching voltage to cable rating (e.g., 80kV peak for 35kV XLPE), load capacitance to length, and features like onboard memory/USB export.
Load Capacitance: 1VLF AC/DC hipot high voltage testers with diagnostics handle capacitance loads up to 1.25µF, supporting cable lengths over 10km at peak voltages like 52kV for 35kV systems.
Frequency Options: 80.1Hz, 0.05Hz, and 0.02Hz selectable frequencies for different cable lengths.
Safety Features: 8Overvoltage, high/low side overcurrent protection with ≤10ms response.
Portability: 2For MV power cables rated 5-35 kV, VLF Hipot test systems deliver reliable results with portable designs weighing under 50 kg.
Diagnostic Functions: Look for integrated tan delta and partial discharge capabilities.
Standards Compliance: 1Prioritize CE-certified very low frequency power cable VLF hipot testers with overcurrent protection and sine wave purity >98%.
Standard VLF Hipot Test Procedure
10 The standard procedure includes preparation, parameter setting, voltage ramp-up, observation, and voltage ramp-down with discharge. First, verify insulation resistance, cable length, and rated voltage. Set the test voltage, frequency, and duration in the VLF Hipot Tester. The tester gradually increases voltage to the target value and maintains it for a specified period while monitoring leakage current and waveform stability. Stable current without abnormal spikes confirms proper insulation. After testing, gradually lower the voltage and discharge the cable to remove stored energy, ensuring safety and accurate test results.
