Why is DC hipot test kit for electrical power cables Better?

High Point represents high potential and is a term used for a specific class of test equipment for electrical insulation.

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Hipot testers are the reverse of the continuity tester- it conducts the discontinuity test checking no current flow condition between two points. Hipot tests are conducted to find crushed, or leakage in the insulation, and the Hipot tester is used for the ac dc hipot tester.

Let&#;s discuss the differences between DC and AC hipot. 

AC Hipot Tester

With an ac hipot tester, a long ramp time is usually not needed. The AC testing also has the benefits of checking both polarities of voltage and not requiring to discharge of the DUT after completing the testing. This testing also has its fair share of disadvantages &#; the test must consider the effects of both real and active currents. When an AC voltage is applied, the flowing current equals the voltage divided by the impedance.

But the impedance is complex as it contains both resistive and capacitive components.

The two components are out of phase with each other and combine in a complex manner to form the total current. As the magnitudes of these compounds can be different, the leakage current of a product with large amounts of capacitance can, with some testers, increase significantly without getting detected by the test.

Dc Hipot Tester

A DC hipot test applies a voltage with gradual steps, commonly known as ramping. It pauses after every increase to allow the capacitance of the DUT to absorb a charge and stabilise. The time needed for the charging current to decay after every step is known as the stabilisation time. The current flowing post the stabilisation time has passed represents the leakage current via insulation.

In case the voltage steps are too large, the sharp rise in charging current when the step gets applied might exceed the high current limit, causing the test to fail prematurely. It is important to carefully match the magnitude and timing of the steps to the characteristics of the DUT.

As a DC hipot test charges the capacitance of a DUT, the charge itself proves to be a hazard to testing personnel. It must be removed after the test is over.

Usually, the hipot tester will automatically discharge the DUT for the same period the test voltage was applied.

Conclusion

The DC hipot tester will use a higher voltage than the AC hipot tester, and the DC hipot test will use the DC voltage, whereas the Ac hipot test uses AC voltage at 50/60 Hz. DC hipot tester provides a more accurate reading of the leakage current as it only reads real current. AC hipot tester, on the other hand, measures total current and does not provide accurate leakage current measurement.

Udeyraj provides high voltage cable testing equipment like the ac high voltage tester, ac dc hipot tester that is quality -centric and reliable. These instruments are accurate, durable, and designed for performing high voltage withstand/breakdown tests on various electrical and electronic products, systems and components.

When it comes to high voltage (HV) cables testing, HiPot testing is a widely used methodology. HiPot tests help to detect any insulation faults or weaknesses that could later impact the performance and safety of the cable. Two commonly used tests are the High Voltage AC and DC Hipot test.

For more information, please visit DC hipot test kit for electrical power cables.

The main difference between the two tests is that High Voltage AC Hipot test applies an alternating voltage to the cable at a frequency between 50 to 60 Hz. On the other hand, a High Voltage DC Hipot test applies a direct voltage to the cable.

When compared, High Voltage DC Hipot test is known to be a more effective test for HV cables as a DC voltage test can help detect more faults in the system due to its ability to penetrate deeper into the insulation. AC voltage, on the other hand, may clear some corona or partial discharges than with DC voltage, thus may not show up all the time.

One advantage of the AC Hipot testing is that it is less likely to cause irreversible dielectric breakdown in the cable insulation. This is because the sinusoidal waveform of AC voltage allows for charge to be dissipated along the cable insulation, minimizing the formation of any potential voids or weak areas which may lead to dielectric failure. AC voltage also has the added benefit of being able to test both the insulation and the cable's shield and/or jacket simultaneously. 

  On the other hand, one downside of AC Hipot testing is the limited ability to detect certain types of cable defects. For example, AC Hipot testing is not able to reveal small pinholes in the insulation or impurities in the cable material.

In terms of DC Hipot testing, one of its major advantages is its ability to detect and reveal such defect types as pinholes, voids, impurities, and other types of gas inclusions which may be present in the cable insulation. DC voltage also readily penetrates through the insulation and reaches the conductor, making it useful for detecting surface contamination on the conductor.

However, one disadvantage of DC Hipot testing is that it may cause irreversible damage to the cable insulation if care is not taken. This is because DC voltage does not easily dissipate through the insulation as it does in AC voltage, and thus has the increased potential to cause partial discharges and dielectric breakdown if proper precautions are not taken. Additionally, DC Hipot testing cannot test the cable's shield or jacket insulation.

Leakage current is another important consideration for both AC and DC Hipot testing. With AC Hipot testing, the cable capacitance and the test voltage frequency interact to produce a capacitive current that is typically measured to assess insulation performance. However, leakage current measurement becomes more critical with DC Hipot testing due to the constant high voltage applied.

DC Hipot testing cables must be monitored closely for leakage current as this method stresses the insulation material much more than AC Hipot testing. The insulation resistance and its variation over time are also measured. The measurement of leakage current is critical in determining the overall insulation health and determining whether any repairs or replacements are necessary.

In conclusion, while both AC and DC hipot testing methods have their pros and cons, and Phenix Technologies stands out as a reliable manufacturer of both systems. We have years of experience and expertise in both AC and DC HV cable testing. Our AC and DC hipot testing systems are designed to be safe and effective in detecting and locating various types of cable defects.

We understand that choosing between AC and DC HV cable testing can be a tough decision. In addition, you may find yourself confused when selecting the appropriate testing equipment for your needs. That&#;s why we&#;re here to help! We can even offer a combination of AC/DC testing units. This versatile equipment is universal and can be used up to the range of 100 kV AC/ 120 kV DC cable testing. By combining these two types of testing, we can offer you a much broader range of testing capabilities, ensuring that all your needs are met.

If you are looking for more details, kindly visit DC hipot test kit for motors.