VLF-90
The VLF-90 is a 90 kV peak sinusoidal VLF hipot test set that brings the family's highest rating…
- Maximum output voltage 0 – 90
- Output current 0 – 30
- Output frequencies 0.1 / 0.05 / 0.02 / 0.01
VLF-34TD
34 kV VLF Hipot & Tan-Delta Diagnostic Test Set
Single-unit 34 kV VLF system combining withstand, tan-delta diagnostics, DC and sheath test with fault location for 5–15 kV cable.
VLF sine wave output
0 – 34 / 0 – 24
DC output
± 0 – 34
Output current
0 – 14
Output frequencies
0.1 / 0.05 / 0.02 / 0.01
Tan-delta accuracy
1.0 × 10⁻⁴
Weight
22
Overview
Technical Specifications
| Specification | Value | Unit |
|---|---|---|
| VLF sine wave | 0 – 34 kV peak / 0 – 24 kV AC RMS · resolution ± 0.1 kV · accuracy ± 1 % | |
| VLF square wave | 0 – 34 kV peak · resolution ± 0.1 kV · accuracy ± 1 % | |
| DC (proof test, sheath test) | ± 0 – 34 kV · resolution ± 0.1 kV · accuracy ± 1 % | |
| Output current | 0 – 14 mA · resolution 1 µA · accuracy ± 1 % | |
| Output frequency | 0.1 / 0.05 / 0.02 / 0.01 | Hz |
| @ 0.1 Hz | 1.0 µF @ 34 kV peak | |
| @ 0.05 Hz | 2.0 µF @ 34 kV peak | |
| @ 0.02 Hz | 5.0 µF @ 34 kV peak | |
| Maximum voltage | 10 | kV |
| Test current | 0.1 – 5.0 | mA |
| Maximum voltage | 10 | kV |
| Pulse / period modes | 1:3 / 4 s · 1:5 / 4 s · 1:5 / 6 s · 1:9 / 6 s | |
| Frequency | 0.1 / 0.05 / 0.02 / 0.01 | Hz |
| Load range | 5 nF – 10 | µF |
| TD range | 0.01 … 999.99 × 10⁻³ | |
| Accuracy | 1.0 × 10⁻⁴ | |
| Resolution | 1.0 × 10⁻⁵ | |
| Capacitance range / accuracy | 0 – 18.0 µF · typ. 20 % | |
| Resistance range / accuracy | 0.1 – 20 GΩ · typ. 10 % | |
| Internal memory | 128 test records | |
| Interface | USB (data export, firmware update) | |
| Dimensions (L × W × H) | 510 × 310 × 480 | mm |
| Weight | 22 | kg |
| Design | Single integrated unit | |
| Power supply | AC 100 – 240 V, 1-phase, 50/60 Hz | |
| Operating temperature | −10 … +50 | °C |
| Storage temperature | −20 … +70 | °C |
| Humidity | ≤ 90 % RH | |
Key Features
Four-in-one cable test system
VLF withstand, tan-delta diagnostics, DC proof test and sheath test with fault location in one integrated 22 kg unit.
VLF sine wave to 34 kV peak
0 – 34 kV peak / 0 – 24 kV AC RMS output with four frequencies from 0.1 Hz to 0.01 Hz.
Square wave and DC modes
0 – 34 kV peak square wave and ± 0 – 34 kV DC for special applications and proof/sheath tests.
Integrated tan-delta diagnostics
TD accuracy 1.0 × 10⁻⁴ and resolution 1.0 × 10⁻⁵ over a 5 nF – 10 µF load for water-tree ageing assessment.
Sheath test & fault location
Up to 10 kV sheath test at 0.1 – 5.0 mA with selectable fault-location pulse modes.
USB export & firmware update
128 internal test records exportable to a PC via USB for report generation; firmware updated via USB.
Field-friendly single unit
Runs from 100 – 240 V AC with no external PC needed; sized for one-case site deployment.
Applications
5–15 kV cable testing
Installation, acceptance and maintenance testing of shielded power cable in the 5 kV to 15 kV class.
Tan-delta condition assessment
Diagnosing water-tree ageing in aged XLPE/EPR circuits by voltage-dependent dielectric loss.
Monitored withstand testing
Step-test and monitored-withstand protocols for cable insulation with suspect condition.
Sheath integrity & fault location
Testing cable oversheaths and locating sheath-to-earth faults per IEC 60229.
DC proof testing
DC proof tests on cable systems and accessories.
Frequently Asked Questions
What does tan-delta (TD) testing add over a plain VLF hipot test?
A VLF withstand test only shows whether a cable breaks down at a given voltage. Tan-delta diagnostics measure dielectric loss and, crucially, how it changes as voltage is stepped. A rising tan-delta with voltage is a classic indicator of water-tree ageing in XLPE insulation, so TD testing can flag a marginal cable before it fails.
Which cable classes is the VLF-34TD intended for?
The VLF-34TD is positioned for installation, acceptance and maintenance testing of shielded power cable in the 5 kV to 15 kV class. Its 34 kV peak output covers the test voltages these circuits require under IEEE 400.2.
Can the sheath fault-location mode pinpoint the exact fault position?
The VLF-34TD applies sheath test and fault-location pulse modes to condition and pre-locate sheath-to-earth faults. Precise distance-to-fault on the route is normally completed with a dedicated cable fault locator / path tracer.
Does it test VLF, tan-delta and DC with a single connection?
Yes. One test set performs VLF withstand, tan-delta diagnostic and DC proof tests on the cable, plus sheath test and fault location on the oversheath, with results stored internally and exported via USB.
Downloads
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