What is hipot test ?, Biology

Hipot is an abbreviation for high potential. Usually, Hipot is a term given to a class of electrical safety testing instruments used to confirm electrical insulation in finished appliances, cables or other wired assemblies, electric motors, printed circuit boards and transformers.

Under normal conditions, any electrical device will create a minimal amount of leakage current due to the voltages and internal capacitance present within the product. Yet because of design flaws or other factors, the insulation in a product can break down, resulting in excessive leakage current flow. This failure condition can cause shock or death to anyone that comes into contact with the faulty product.

A Hipot test (also called Dielectric Withstanding Voltage (DWV) test) verifies that the insulation of a product or component is sufficient to protect the operator from electrical shock. In a typical Hipot test, high voltage is applied among a product''s current-carrying conductors and its metallic shielding. The resulting current that flows through the insulation, known as leakage current, is monitored by the hipot tester. The theory behind the test is that if a deliberate over-application of test voltage does not cause the insulation to break down, the product will be safe to use under normal operating conditions-therefore the name, Dielectric Withstanding Voltage test.

In addition to over-stressing the insulation, the test can also be performed to detect material and workmanship defects, most importantly small gap spacings among current-carrying conductors and earth ground. When a product is operated under normal conditions, environmental factors such as humidity, dirt, vibration, shock and contaminants can close these small gaps and permit current to flow. This condition can create a shock hazard if the defects are not corrected at the factory. No other test can uncover this type of defect as well as the Dielectric Withstand test.

3 types of Hipot tests are commonly used. These 3 tests differ in the amount of voltage applied and the amount (or nature) of acceptable current flow:

Dielectric Breakdown Test. The test voltage is enhanced until the dielectric fails, or breaks down, allowing too much current to flow. The dielectric is often destroyed by this test so this test is used on a random sample basis. This test permits designers to estimate the breakdown voltage of a product''s design and to see where the breakdown occurred.

Dielectric Withstanding Voltage Test. A standard test voltage is applied (below the established Breakdown Voltage) and the resulting leakage current is monitored. The leakage current must be below a preset limit or the test is considered to have failed. This test is non-destructive and is usually needed by safety agencies to be performed as a 100% production line test on all products before they leave the factory.

Insulation Resistance Test. This test is used to give a quantifiable resistance value for all of a product''s insulation. The test voltage is applied in the same fashion as a standard Hipot test, but is specified to be Direct Current (DC). The voltage and measured current value are used to calculate the resistance of the insulation.

 

Posted Date: 3/11/2013 2:47:38 AM | Location : United States







Related Discussions:- What is hipot test ?, Assignment Help, Ask Question on What is hipot test ?, Get Answer, Expert's Help, What is hipot test ? Discussions

Write discussion on What is hipot test ?
Your posts are moderated
Related Questions
Case scenario Mr Kit Lee, a 28-year-old unrestrained driver of a utility, was travelling on a highway at 100kph and swerved to miss road debris. He lost control and struck a tre

TYPES OF CELL WALL Cell wall differentiated into the following layers : 1. Primary Cell Wall       2. Secondary Cell wall             3. Tertiary Cell wall 1 .

ADP-ATP system  of energy  exchange : In 1929 Lohmann, Fiske and  subbarow  published  their  discovery  that the energy  exchanges  compounds in all biological  systems  are t

Poxvirus zoonoses Naturally occurring poxvirus infections affect humans and many species of animals and insects. However, for most part, poxviruses other than variola cause self-l

Vitamins Vitamins, as you may already know, derive its name from the word 'Vital Amine'. These are the organic compounds required for normal metabolism, growth and developme

Which of the following best explains mechanisms by which histones interact with DNA? A. Histone core proteins interact with the main groove of DNA by the helix-turn-helix-turn

Recovery of tar: the coke oven gas coming out from ovens is passed through a tower where liquid ammonia is sprayed. The tar and dust are removed and then recovered. Recover of

Q. Describe the Morphological Characteristics? One of the first steps in the identification of bacteria in food is microscopic examination to ascertain the shape, size, aggreg

What is meant by concentration gradient? Is it correct to refer to "concentration gradient of water"? Concentration gradient is the difference of concentration of a substance

structure of oxysome