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3KV/mm or 3X10^6 V/M
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Which is another name for dielectric strength test?
ASTM D149 - 09 Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies
What is difference between breakdown voltage and dielectric strength of transformer?
The dielectric strenght of a transformer represents the maximum voltage permissible to apply across the transformer insulation i.e. between the transformer winding to another part of the transformer, normally the chassis or another winding and without break-down of the insulation ocurring (e.g. arcing). The breakdown voltage of a transformer represents a voltage that exceeds its dielectric strenght and that causes breakdown e.g. arcing across the insulation.
What is BDV test for distribution transformer?
When you say BDV you might mean the dielectric strength of transformer oil. A new transformer oil should have at lest a dielectric strength of 39 KV. from a British standard.Transformer oils used are normally tested using ASTM D877-82 with the KV strength tester using 1" electrodes spaced 0.1" apart and the test voltage increased at 3,000 volts/min until it breaks down. The average Kv obtained after 8 trials is considered the Oil dielectric strength.Using this test method,dielectric strength at 30 kv and above is considered good. Dielectric strength between 23 to 29Kvis considered usable, but requires filtering. Below 23 kv, the transformer oil should be replaced.Another method ASTM D18747-82 uses the small radius electrodes but spaced only .o4 inches. The test voltage is 500volts/min and increased until breakdown. The dielectric strength is still the average Kv obtained in 8 trials. The dielectric strength of 28-29Kv is considered good. Below 28 kv, the transformer oil is usable but requires filtering. The latter method is considered a better test method
A parallel plate capacitor has a plate separation of 1.0 mm How much potential difference can be placed across the capacitor before dielectric breakdown of air occurs?
You need more information than this to find your solution. There will be a a value for the electric field at which point the air will break down. you also need the area of one of the capacitors and the capacitence
WHAT will happen if you run oil transformer with out oil?
As well as providing a cooling medium, transformer oil is also used to insulate a transformer. As its dielectric strength (how well it insulates) is much higher than air, it means that components within a transformer that are at different potentials can be placed much closer together if they are immersed in oil. So, operating an oil-filled transformer without oil will likely cause insulation breakdown within the transformer.
What is the dielectric breakdown strength?
This depends on the particular dielectric. Each has a different breakdown strength.
What is dielectric breakdown?
The dielectric breakdown strength is 3,000 volts per millimeter.
How does humidity affect the dielectric breakdown strength of air?
Generally, dielectric breakdown strength decreases with increasing humidity. In air, exact relationships between dielectric strength and humidity are hard to derive, due to the numerous other variables compounding the relationships (e.g. electrode size and shape, air temperature and pressure). Sources: http://www.scienceforums.net/topic/37206-dielectric-strength-of-air/ http://en.wikipedia.org/wiki/Dielectric_strength
How does the moisture and temp effect the breakdown strength solid dielectric?
Generally, increased moisture levels will lower breakdown strength, especially if the dielectric readily absorbs water. Increasing temperature generally decreases breakdown strength of solid dielectrics. The dielectric strength of some materials may increase with temperature within limited temperature ranges. However, dielectric strength eventually begins to decrease at higher temperatures.
Which is another name for dielectric strength test?
ASTM D149 - 09 Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies
What happens when dielectric breakdown occurs?
The dielectric,usually the insulator between the plates of a capacitor, can be overstressed by the application of too high voltages applied to the capacitor plates. The dielectric breaks down and a current flows between the plates until,either they are discharged, or an equilibrium is reached,below the working voltage of the capacitor. If the dielectric is damaged in this process he capacitor must be replaced. Some dielectric material self heal and can recover from an over voltage.
What is dielectric strength?
The dielectric strength refers to the maximum working voltage that a material can withstand without breaking down. At breakdown the electric field frees bound electrons turning the material into a conductor.
Difference between insulation resistance and dielectric strength?
INSULATION RESISTANCE: The insulation resistance is a measure of the capability of a material to withstand leakage of current under a Vdc potential gradient. DIELECTRIC STRENGTH: The dielectric strength is a measure of the ability of the material to withstand a large field strength without electrical breakdown, and is usually expressed in volts per mil (.001') or volts per cm of dielectric.
What is the unit of dielectric strength?
In SI, the unit of dielectric strength is volts per meter (V/m). In U.S. customary units, dielectric strength is often specified in volts per mil.In physics, dielectric strength 2 meanings:Of an insulating material, the maximum electric field that a pure material can withstand under ideal conditions without breaking down.For a specific configuration of dielectric material and electrodes, the minimum applied electric field that results in breakdown.
Dielectric strength of air in s.t.p?
3 × 10^6 V/m
What is the material use in the capacitor?
Capacitors are named after their dielectrics. So, an 'air capacitor' uses air as its dielectric, a 'mica capacitor' uses mica as its dielectric, and so on. There are lots of different dielectric used to separate the plates of a capacitor, each with different permittivities and dielectric strengths. As the perfect dielectric (i.e. one with both a very high permittivity and a very high dielectric strength) doesn't occur, the choice of dielectric is always a compromise between it permittivity and dielectric strength.
Is there any change in the current or voltage coming from the other end of the dielectric after the dielectric breakdown occurs?
Yes. Once dielectric breakdown occurs the circuit is now completed through a conductive breakdown channel in the dielectric. The current injected in one end of the dielectric is matched by the current coming out of the other end.
