Category Archives: Electrical Testing

The Applied Voltage Test (AV) is a fundamental dielectric test performed on power transformers to verify the integrity of insulation between windings and earth. Unlike impulse tests that simulate lightning or switching surges, the Applied Voltage Test checks the transformer’s ability to withstand power-frequency overvoltages under controlled conditions. Defined in IEC 60076-3, the Applied Voltage Test is a… Read More »

The Switching Impulse Test (SI) is a critical dielectric test used to verify the insulation strength of high-voltage and extra-high-voltage power transformers under slow-front overvoltage conditions. Unlike lightning impulse tests, which simulate very fast surges, the switching impulse test represents overvoltages caused by system switching operations, such as line energization, fault clearing, or circuit-breaker reclosing. IEC 60076-3 defines… Read More »

The Neutral Terminal Lightning Impulse Test (LIN) is a specific dielectric test defined in IEC 60076-3 for power transformers. Unlike the standard lightning impulse test applied to line terminals, the LIN test is applied directly to the neutral terminal of a winding to verify the adequacy of its insulation under lightning-type overvoltages. Although the LIN test is not… Read More »

The Chopped Wave Lightning Impulse Test is one of the most severe dielectric tests performed on high-voltage power transformers. While a normal lightning impulse test checks how a transformer handles a standard 1.2/50 μs surge, the chopped wave represents a much sharper, more dangerous type of overvoltage that can happen in real power systems. IEC 60076-3 requires the… Read More »

Lightning Impulse (LI) testing is one of the most important dielectric tests used in transformer manufacturing. It ensures a transformer can survive the types of electrical stresses created by lightning strikes on overhead power lines. Even if a substation has surge protection, a transformer may still experience fast and intense voltage surges. For this reason, every medium- and… Read More »

When engineers design a power transformer, one of the most important decisions they make is how strong the insulation needs to be. Proper insulation ensures that the transformer can survive real-world electrical stresses such as lightning, switching operations, and temporary overvoltages. IEC 60076-3 is the international standard that governs how these insulation levels are defined and how they… Read More »

Choosing the right electrical cable size is one of the most important steps in any electrical job. If the cable is too small, it can overheat, trip protection devices, fail short-circuit checks, or cause voltage drop problems. If the cable is too large, the installation becomes more expensive than necessary. A Cable Sizing Calculator removes the guesswork. It… Read More »

Are you struggling with complex number calculations for your math homework, engineering projects, or electrical circuit analysis? Look no further! Our free complex number calculator makes it simple to perform operations like addition, subtraction, multiplication, division, exponentiation, and even parallel impedance calculations. Whether you’re converting between rectangular and polar forms or handling advanced computations, this tool is designed… Read More »

Voltage drop is a common issue in electrical installations, and if you’ve ever dealt with dim lights, weak motors, or mysterious performance problems, voltage drop is often one of the first things to check. The good news is that it’s predictable—and with the right tool, you can calculate it in seconds. This voltage drop calculator gives you clear,… Read More »

During transformer commissioning, one of the most important diagnostic procedures is the power factor test. This test assesses the dielectric losses in the transformer’s insulation system, which are directly related to insulation quality and integrity. For dry-type transformers, the power factor test helps identify potential insulation deterioration due to moisture, contamination, carbonization, or other degradation mechanisms that may… Read More »