VLF Hipot Test Sets
Very-low-frequency withstand testing for capacitive power equipment. Atlas Energy supplies the HVEX VLF Hipot test set for shielded power cables, large motors, and generators. Digital frequency conversion and microcomputer control automate voltage increase, reduction, measurement, and protection while limiting the power required to energize high-capacitance test objects.
Verified ratings
Maximum output: 50 kV peak.
Selectable output frequencies: 0.1, 0.05, and 0.02 Hz.
Maximum load at 0.1 Hz: 1.1 µF.
Maximum load at 0.05 Hz: 2.2 µF.
Maximum load at 0.02 Hz: 5.5 µF.
Supply: 220 V AC ±5%, 50 or 60 Hz.
Published measurement accuracy: 3%.
Positive and negative voltage peak error: ≤3%; voltage waveform distortion: <5%.
Operating temperature: −10 to +40 °C (14–104 °F); relative humidity ≤90% without condensation.
Control and protection
Voltage, current, and waveform data are sampled directly on the high-voltage side. The overvoltage protection circuit interrupts the supply when the output exceeds the selected limit, with a published response time below 20 ms. The system combines a control case and a high-voltage step-up circuit for field and laboratory testing.
Applications
Acceptance and maintenance withstand tests on shielded power cables.
Applied-voltage testing of large motors and generators.
Testing of capacitive insulation systems within the selected frequency and load limits.
More than one cable phase may be tested together when the total connected capacitance remains within the equipment rating and the test procedure permits it. Set test voltage and duration according to the equipment and the applicable procedure.
Test program and accessories
The HVEX datasheet references IEC 60502-2, CENELEC HD 620/621, DIN VDE 0276-620/621, and IEEE Std 400. It describes insulation-resistance testing with a separate megohmmeter before the VLF withstand test. Capacitance, tan delta, and partial discharge measurements require the appropriate additional measurement equipment and configuration. Contact Atlas Energy with your cable or machine ratings, capacitance, and required test program to specify the HVEX system.
