IEEE 1783-2009 pdf free.IEEE Guide for Test Methods and Procedures to Evaluate the Electrical Performance of Insulators in Freezing Conditions.
The guide specifes procedures for testing equipment when extermal insulation of the test object is subjected to combinations of contamination, ice, snow, or cold fog. The methods are applicable only to tests on equipment with a rated voltage above I kV.
1.2 Purpose
The test methods recommended in this guide supplement the general requirements regarding equipment,objects, and procedures for standard high-voltage testing. The guide also describes some recommended methods evaluating the test results.
2. Normative references
The following referenced documents are indispensable for the application of this document (ie,, they must be understood and used, so each referenced document is cited in text and its relationship to this document is explained). For dated references, only the edition cited applies. For undated referenced, the latest edition of the referenced document (including any amendments or corrigenda) applies.
3. Definitions, acronyms, and abbreviations
For the purposes of this document, the following terms and definitions apply. The IEEE Standards Dictionary: Glossary of Terms & Definitions should be referenced for terms not defined in this clause.
3.1 Definitions
accuracy: The degree of agreement of the observed value with the conventionally true value of the quantity being measured.
applied water conductivity: The electrical conductivity of water used to simulate ice, snow, or cold fog accretion on insulators, corrected to 20 °C.
are: A discharge of electricity through a gas, normally characterized by a voltage drop in the immediate vicinity of the cathode approximately equal to the ionization potential of the gas.
atmospheric icing: The expression “atmospheric icing” comprises all processes where drifting or falling waler droplets, rain. drizzle, or wet snow in the atmosphere freeze or stick to any object exposed to the weather.
cold fog (freezing fog): Visible aggregate of minute, supercooled water droplets suspended near the earth’s surface whose droplets freeze upon contact with exposed objects and form a coating of hoarfrost andor glaze. When composed of ice crystals, it is termed ice fog. According to international definiüons. fog reduces visibility below 1 km. Fog difTers from clouds only in that the base of fog is at the earth’s surface while clouds are above its surface, Fog is distinguished from haze by its appreciable dampness and grey color. Mist may be considered as intermediate between fog and haze. Near industrial and hcay traffic areas, fog is often mixed with smoke and vehicle exhaust, and this combination is known as smog.
conductivity: A material property given by the conduction-current density, divided by the applied electric- field intensity. In general. it is a complex tensor quantity.
NOTE—In liquids. conductivity is often measured in units of microsiemens per centimeter (iiScrn).7
creepage distance: See: leakage distance
critical Aashos’er voltage: The amplitude voltage of a given wave shape that, under specified conditions. causes fiashover through the surrounding medium on 50% of the voltage applications.
critical Impulse f1ashoer voltage (CFO): The crest value of the impulsc voltage wave that. under specified conditions, causes disruptive discharge through the surrounding medium on 50% of the applications.
dee-point temperature: The temperature at which the water vapor in the gas begins to condense.
discharge: The passage of electricity through gaseous, liquid, or solid insulation that does iiot normally conduct electricity. Discharge is associated with nonlinear processes of avalanche ionization and development of electrically conducting plasma that may or may not be luminous.
disruptive discharge (flashoser): A discharge that completely bridges the insulation under test, reducing the voltage beween the electrodes to a finite value that is nearly constant for all currents and is negligible with rcspcct to the supply voltage.
disruptive discharge probability (flashover probability): The probability that one application of a prospective voltage of a given shape and type may cause a disruptive discharge.
disruptive discharge voltage (flashoer voltage): The voltage causing the disruptivc discharge for tests with direct voltage, alternating voltage, and impulse voltage chopped at or after the peak; the voltage at the instant when the disruptive discharge occurs for impulses chopped on the front.IEEE 1783 pdf download.