Test Methods for Lacing Twines and Tapes Used as Harnesses in Electrical Equipment (Discontinued 2000)

Discharge of failure was the fault type are likely to occur in transformers, bushings, transformers, and the extent of damage to the equipment is a serious and direct impact on the stable operation of the system, first introduced the principle and gas chromatographic analysis its test methods, then gas chromatography equipment discharge failure is how to judge the conduct described. Through the analysis of transformer oil chromatographic method can be found as early as possible transformers and other equipment inside the existence of latent failures, thus chromatography is to oversee and guarantee the safe operation of an important means of transformer.

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Terahertz-Based Method for Accurate Characterization of Early Water Absorption Properties of Epoxy Resins and Rapid Detection of Water Absorption

Polymers ◽

10.3390/polym13234250 ◽

2021 ◽

Vol 13 (23) ◽

pp. 4250

Author(s):

Hongchuan Dong ◽

Yunfan Liu ◽

Yanming Cao ◽

Juzhen Wu ◽

Sida Zhang ◽

...

Keyword(s):

Water Absorption ◽

Epoxy Resin ◽

Moisture Absorption ◽

Prediction Method ◽

Electrical Equipment ◽

Test Methods ◽

Test Time ◽

Terahertz Time Domain Spectroscopy ◽

Term Operation ◽

Trace Moisture

Moisture is detrimental to the performance of epoxy resin material for electrical equipment in long-term operation and insulation. Therefore, moisture absorption is one of the critical indicators for insulation of the material. However, some relevant test methods, e.g., the direct weighing method, are time-consuming, and it usually takes months to complete a test. For this, it is necessary to have some modification to save the test time. Firstly, the study analyzes the present prediction method (according to ISO 62:2008). Under the same accuracy, the time required is reduced from 104 days to 71 days. Subsequently, the Langmuir curve-fitting method for water absorption of epoxy resin is analyzed, and the initial values of diffusion coefficient, bonding coefficient, and de-bonding coefficient are determined based on the results of molecular simulation, relevant experiment, and literature review. With the optimized prediction model, it takes only 1.5 days (reduced by 98% as compared with the standard prediction method) to determine the moisture absorbability. Then, the factors influencing the prediction accuracy are discussed. The results have shown that the fluctuation of balance at the initial stage will affect the test precision significantly. Accordingly, this study proposes a quantitative characterization method for initial trace moisture based on the terahertz method, by which the trace moisture in epoxy resin is represented precisely through the established terahertz time-domain spectroscopy system. When this method is used to predict the moisture absorbability, the experimental time may be further shortened by 33% to 1 day. For the whole water absorption cycle curve, the error is less than 5%.

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Electrical equipment used for detection and concentration measurement of refrigerant gases - Performance requirements and test methods

10.3403/30356946u ◽

2020 ◽

Keyword(s):

Electrical Equipment ◽

Test Methods ◽

Concentration Measurement ◽

Performance Requirements

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Considerations regarding test methods against dust and water ingress protection for Ex equipment

MATEC Web of Conferences ◽

10.1051/matecconf/202235400048 ◽

2022 ◽

Vol 354 ◽

pp. 00048

Author(s):

Niculina Vătavu ◽

Mihaela Părăian ◽

Sorin Vătavu ◽

Mihai Popa

Keyword(s):

Health And Safety ◽

Essential Element ◽

Electrical Equipment ◽

Test Methods ◽

Water Ingress ◽

Degree Of Protection ◽

Normal Degree ◽

Explosion Protection ◽

European Standards ◽

Explosion Risk

The explosion danger in all industries where explosive atmospheres generated by the mixture of combustible dusts or flammable gases with air may form, must be treated as a major hazard, as the explosions that may occur can seriously affect both health and safety people, as well as the environment. It is therefore necessary to assess the explosion risk and to establish appropriate measures to reduce it to acceptable levels in accordance with the requirements of the European Directives. An essential element in the assessment of the explosion risk for electrical and non-electrical equipment intended for use in potentially explosive atmospheres is the way in which an appropriate normal degree of protection is provided through the equipment housing (protection against touching of dangerous parts inside the equipment housing and protection against the ingress of dust and water inside it). The aim of the paper is to highlight compliance with the requirements of the ATEX Directive, given that this protection is a basic requirement for explosion protection and to present the important elements to be considered for the assessment of the normal degree of protection and the development of harmonized test methods with the requirements of European standards.

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Research on the improvement of test methods for the determination of dust penetration in enclosures of equipment intended for explosive atmospheres

MATEC Web of Conferences ◽

10.1051/matecconf/202030500063 ◽

2020 ◽

Vol 305 ◽

pp. 00063

Author(s):

Niculina Vătavu ◽

Adrian Jurca ◽

Sorin Vătavu ◽

Dan Gabor

Keyword(s):

Foreign Bodies ◽

State Of The Art ◽

Electrical Equipment ◽

Test Methods ◽

Water Penetration ◽

Degree Of Protection ◽

Explosion Protection ◽

European Method ◽

Solid Bodies

Carcasses of electrical or non-electrical equipment operating in potentially explosive atmospheres must provide a certain degree of protection against access to hazardous parts, penetration of solid bodies and/or water penetration, which must be tested according to the specifications of the Ex protection types. Normal protection classes are indicated by the international IP code followed by two characteristic digits referring to the protection against penetration of solid foreign bodies and water protection, followed by optional letters if required by the beneficiary according to the imposed conditions of use. Within the ENExEMEIP laboratory, have been developed laboratory tests to verify the first characteristic figure of the standard degree of protection according to the standardized European method. In the paper is presented the test stand of the large gauge equipment, a stand made with state-of-the-art equipment that provides the necessary performance for the accreditation of the test according to the standardized requirements. Checking dustproof protection to equipment used in areas where explosive atmospheres generated by combustion dust may occur is particularly important for assessing compliance with the requirements of the ATEX Directive [5], as this protection is a basic requirement for explosion protection.

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