High Voltage (HV) Testing Services in Pakistan.
TransfoLine delivers certified High Voltage (HV) Testing for industrial substations, power plants, and distribution networks across Pakistan. Our testing division performs AC/DC Hipot, Very Low Frequency (VLF) cable testing, Partial Discharge (PD) diagnostics, and lightning impulse withstand tests up to 100kV to prove equipment dielectric integrity and eliminate energization risks.
What is High Voltage Testing?
High voltage (HV) testing—commonly known as Hipot or dielectric withstand testing—evaluates the ability of electrical insulation in transformers, switchgear, busbars, and power cables to safely withstand overvoltages caused by lightning strikes, grid switching surges, and continuous high-voltage operation without flashover or dielectric puncture.
AC / DC Hipot Withstand Testing
Applies high overvoltage potential for 60 seconds across primary insulation barriers. If leakage current remains within specified milliamp thresholds without breakdown, the equipment is officially certified safe for grid energization.
VLF (Very Low Frequency) Cable Testing
Utilizes 0.1 Hz AC sinusoidal test waveforms per IEEE 400.2 standards to test 11kV and 33kV XLPE power cables without creating destructive electrical treeing inside the cable dielectric.
Our High Voltage Testing Solutions
Standard High Voltage Test Levels (IEEE & IEC)
| Rated Voltage (System Class) | Power Frequency Withstand (AC) | DC Hipot Test Level | VLF Withstand (0.1 Hz RMS) |
|---|---|---|---|
| 3.3 kV System | 10 kV AC (1 min) | 14 kV DC | 6 kV RMS |
| 11 kV System (Most Common) | 28 kV AC (1 min) | 36 kV DC | 19 kV RMS |
| 22 kV System | 50 kV AC (1 min) | 65 kV DC | 34 kV RMS |
| 33 kV System | 70 kV AC (1 min) | 90 kV DC | 54 kV RMS |
Frequently Asked Questions.
Guidance on high voltage safety and test procedures.
SAFETY What safety precautions are taken during HV testing?
All high-voltage testing is conducted within cordoned safety zones with flashing beacon indicators, manual emergency trip sticks, dual-ground discharge rods, and strict lockout/tagout (LOTO) protocols.
PASS/FAIL What happens if an asset fails the Hipot test?
If dielectric breakdown occurs, the test is automatically interrupted. Our engineers locate the breakdown point (e.g. cable termination, bushing flashover, or winding void) and provide repair solutions immediately.
Schedule a High Voltage Test.
Our HV test teams deploy across Pakistan with fully equipped mobile units.
Need urgent cable testing or substation pre-commissioning Hipot testing? Contact us directly.