定价： 481元 / 折扣价： 409 元 加购物车

This specification deals with soft magnetic manganese zinc ferrite core materials for high frequency power transformer and filter inductor applications. Standard types of both power transformer and filter inductor material are defined. For power transformer use, there are five types defined by their maximum core loss density and minimum saturation flux density. For filter inductor materials, three types are defined based on their inductance permeability. Apart from magnetic property requirements, dimensional tolerances and workmanship requirements are defined in this specification.1.1 This specification covers the requirements to which the specified grades of soft magnetic manganese zinc (MnZn) ferrite materials shall conform. Cores made from these materials are used primarily in transformers and inductors.1.2 Frequency—MnZn ferrite cores are primarily used for frequencies in the range of 10 kHz to 1 MHz. Many inductors have a DC component as well.1.3 Magnetic Flux Density—Applications consist of two main categories, high and low magnetic flux density.1.3.1 High Magnetic Flux Density—Transformers used for power conversion. Inductors or chokes used in high current applications.1.3.2 Low Magnetic Flux Density—Transformers, inductors, chokes used for signal conditioning.1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to customary (cgs-emu and inch-pound) units, which are provided for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

Gases may be formed in oil-filled electrical equipment as a result of faults. The type of fault and its severity may often be inferred from the composition of the gases.Gas samples are taken from transformer gas spaces or from gas-collector relays in order that the composition of the gas sample may be determined.In nitrogen-blanketed transformers, the gases generated by a fault will partition between the gaseous and liquid phases. On transformers with gas-collector relays, gas in the form of bubbles may collect in a gas-collector relay and provide a means to obtain a gas sample for analysis.Do not draw samples from an energized instrument transformer.1.1 This practice covers the sampling of gas from a transformer gas space or from a gas-collector relay where the volume of gas available is small and will not permit the use of Practice D 2759.1.2 This practice covers sampling, using a gas-tight syringe as the sampling apparatus and container.1.3 If the apparatus to be sampled is found to be under a negative pressure, the apparatus pressure should be raised by the addition of nitrogen gas until a positive pressure is obtained.This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

定价： 0元 / 折扣价： 0 元

This PDF includes GI #2. 1. Scope 1.1 This Standard applies to outdoor bushings that have lightning impulse insulation levels 110-1950kV. They are for use as components of liquid-filled transformers and reactors on systems with a nominal voltage of

定价： 455元 / 折扣价： 387 元

定价： 605元 / 折扣价： 515 元 加购物车

2.1 A gas sample from above the insulating liquid in transformers and other electrical power apparatus can be used to give an early indication of developing fault conditions. Combustible gases are formed from the breakdown of the insulating materials under thermal and electrical stress. Excessive concentrations of combustible gases indicate the need to take appropriate action.2.2 It is important that gas samples from equipment be taken from the gas space directly above the liquid level, and not from remote expansion compartments, such as tank bracing bands.2.3 The procedure described should be carefully followed to ensure that the sample is not diluted by air or nitrogen, or contaminated by residual materials in the sampling bottle.1.1 This practice covers the sampling of gas above the insulating liquid of a transformer. A gas sampling bottle collects the gas sample from the gas space that is at a positive pressure.1.2 Representative samples of gas are taken for analysis to determine their compositions.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车